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This 3-page document provides an overview and summary of the March 2009 issue of Compendium: Continuing Education for Veterinarians. It includes information about CE articles, editorial staff, peer review process, subscription information, and indexing. The key points are: - The issue contains CE articles on vomiting treatment options, stress-induced hypersensitivity in cats, and squamous cell carcinoma. - The editorial board and staff are listed, including the editor in chief, managing editor, veterinary advisor, art directors, and more. - Compendium is peer reviewed, indexed in several databases, and aims to provide continuing education to veterinarians. - Subscription rates and methods of payment are
![Letters
Five Common Toxins
and Activated Charcoal
I have a question for the author about his re-
search for the November 2008 Pharm Profile
article, “Activated Charcoal.” The article states
Pharm Profile
that charcoal is contraindicated for metalde- Activated Charcoal
hyde ingestion. Yet it is widely accepted that it Lotfi El Bahri, DVM, MSc, PhD
École Nationale de Médecine Vétérinaire
Sidi Thabet, Tunisia
is proper protocol to give activated charcoal in Indication: Emergency treatment of acute poisoning after ingestion of a large
amount of toxin or drug.
Activated charcoal—also known as active carbon, activated carbon, adsorbent charcoal,
these cases. In fact, in the article “Five Com-
medicinal charcoal, or carbo medicinalis1—is a carbon residue derived from vegetable
material (e.g., wood pulp). It is produced by exposing the original material to an oxi-
dizing gas compound of steam, oxygen, and acids at high temperatures (900°C). This
activation process creates a network of fine pores (10 to 20 nm in size) in the result-
ing charcoal.2 The result is a highly porous material with an enormous surface area
relative to its weight.3 The adsorptive capacity of activated charcoal is a function of
mon Toxins Ingested by Dogs and Cats” in the its binding surface area. In commercial products, the surface area varies from 1000 to
2000 m2 per gram.3,4
PHARMACOKINETICS
Activated charcoal comes as a very fine, porous, black powder or granules measuring
same issue, charcoal is recommended as an less than 1.0 mm in diameter. It does not contain any gritty material.2 It is insoluble in
water and all usual solvents.1 Activated charcoal is not absorbed in the gastrointestinal
tract, and all ingested activated charcoal is excreted in the feces.1 It is a stool marker,
indicating that the toxin has passed through the gastrointestinal tract and no further
significant toxin absorption from the original ingestion will occur.
antidote to help eliminate metaldehyde. I am PHARMACOLOGY
Owing to its large surface area, activated charcoal can adsorb many drugs and toxins
(e.g., acetaminophen, salicylates, digoxin, organophosphate and carbamate insecticides,
pyrethrins and pyrethroids, anticoagulant rodenticides, strychnine) in the upper gas-
trointestinal tract.1–3 It thereby facilitates the excretion of the adsorbed toxicant in the
curious about the discrepancy. Also, I was wondering if there is any Pharm Profile focuses on
new drugs or indications in the
veterinary market as well as
feces and reduces the amount of free agent available for absorption into the blood-
stream. Activated charcoal maintains its attachment to toxins through covalent binding
and van der Waals forces.5
Adsorption of substances onto charcoal is a reversible process, with rapid adsorption
pharmacologic products of high and slow desorption. Optimal adsorption occurs when the ratio of charcoal to toxin is
research on UAA gel, which is mentioned in the Pharm Profile article. interest to practitioners.
Send comments/questions via email to
editor@CompendiumVet.com
10:1 or higher.6 Administration of activated charcoal can lead to a 30% to 40% drop in
digoxin levels within 12 to 18 hours.7 In one canine study, oral administration of acti-
vated charcoal solution (2.5 g/kg) 30 minutes after a single oral dose of carprofen (16
mg/kg) effectively decreased the maximum plasma carprofen concentration (85.9 ±
or fax 800-556-3288. 11.9 mg/L to 58.1 ± 17.6 mg/L) by decreasing carprofen absorption in the gastroin-
testinal tract.8 Elimination of substances that undergo enterohepatic recirculation (e.g.,
Angela LeBrun, CVT Visit CompendiumVet.com for
full-text articles, CE testing, and CE
test answers.
NSAIDs, theobromine, cholecalciferol, tetrahydrocannabinol) may be enhanced by
repeated oral doses of activated charcoal.1,3
Puget Sound Veterinary Referral Center & Animal Emergency Clinic, Tacoma, Washington COMPENDIUM 596 November 2008
I have just finished reading the November tains activated hardwood charcoal and viously. Activated charcoal and a saline
2008 journal and am puzzled by the thermally activated attapulgite clay in cathartic may be given, although [ethyl-
contradiction between the paper by Drs. an aqueous gel suspension. The recom- ene glycol] is not significantly adsorbed
Luiz and Heseltine and that by Dr. El mended oral dosage is 1 to 3 mL/kg in by charcoal.” I verified this information
Bahri in reference to the effectiveness dogs, cats, and large animals. The manu- with the sources cited in the article.1,2
of activated charcoal in the treatment of facturer states that the product should I also gathered information from the
ethylene glycol and metaldehyde poison- be shaken well before use and protected sixth edition of Ettinger’s Textbook of
ings. The former says to use it; the latter from freezing. Veterinary Internal Medicine,3 which
says it’s ineffective. Is there an explana- Lotfi El Bahri, DVM, MSc, PhD states to administer activated charcoal
tion as to the correct information? for recent exposure (≤2 hr). The recom-
References
Philip T. Durfee, DVM, MPH, MVSc 1. Buck WB, Osweiler GD. Metaldehyde. In: Van Gelder mendation we stated is conditional on
GA, ed. Clinical and Diagnostic Veterinary Toxicology. the duration of exposure.
2nd ed. Dubuque, IA: Kendall/Hunt Publishing Compa-
The Authors’ Replies ny; 1976:227-228.
For metaldehyde, we wrote, “If the
The administration of activated charcoal 2. Andreasen JR Jr. Metaldehyde toxicosis in duck- patient presents acutely, is alert, and
in the treatment of metaldehyde intoxi- lings. J Vet Diagn Invest 1993;5:500-501. does not have excessive muscle tremors
3. Booth NH, McDonald LE, eds. Veterinary Pharma-
cation is controversial. Several references cology and Therapeutics. 5th ed. Ames: The Iowa State or seizures, an emetic should be given,
I consulted do not either include1,2 or University Press; 1982:1013-1014. followed by activated charcoal and a
4. Campbell A. Metaldehyde. In: Campbell A, Chap-
recommend3,4 the administration of acti- man M, eds. Handbook of Poisoning in Dogs and Cats.
cathartic.” Again, I verified this statement
vated charcoal in the treatment of met- Oxford: Blackwell Science; 2000:181-185. with the sources cited in the article4,5 as
aldehyde intoxication. The Handbook 5. Shintani S, Goto K, Endo Y, et al. Adsorption effects well as The 5-Minute Veterinary Consult
of activated charcoal on metaldehyde toxicity in rats. Vet
of Poisoning in Dogs and Cats, which Hum Toxicol 1999;41(1):15-18. by Tilley,6 which recommends emetics
is considered a veterinary toxicology or gastric lavage followed by adminis-
reference, states, “Metaldehyde report- I double-checked our sources about the tration of activated charcoal to prevent
edly does not bind to activated charcoal use of activated charcoal in ethylene gly- further absorption in animals with no
and therefore use of adsorbents is not col and metaldehyde toxicoses. For eth- clinical signs.
indicated.”4 On the other hand, activated ylene glycol, we wrote, “Early diagnosis Julie Ann Luiz, DVM
charcoal has been shown to help inhibi- and treatment are critical for a successful
References
tion of metaldehyde absorption in rats.5 outcome. Emetics should be adminis- 1. Osweiler GD. Common household products. In: Nie-
Universal Animal Antidote (UAA) gel tered if no signs are observed and the ginski EA, ed. The National Veterinary Medical Series:
(Vedco, Inc. St. Joseph, Missouri) con- exposure occurred less than 4 hours pre- CONTINUES ON PAGE 114
CompendiumVet.com | March 2009 | Compendium: Continuing Education for Veterinarians® 113](https://image.slidesharecdn.com/pv0309-091029165733-phpapp01/85/Pv0309-19-320.jpg)
Pv0309
- 1. Compendium CompendiumVet.com | Peer Reviewed | Listed in MEDLINE Vol 31(3) March 2009 6 CE Contact Hours CONTI N U I NG EDUCATION FOR VETERI NARIANS ® FREE CE Vomiting Treatment Options Understanding Behavior Stress-Induced Hypersensitivity in Cats FREE CE Squamous Cell Carcinoma t : us rs e 1 nt E t n 05 Tr rro e P Cl ic me Se ng ed ge ag ie al a or M an st ing e M Re los ctic sc Pra i Di
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- 3. March 2009 Vol 31(3) CompendiumVet.com | Peer Reviewed | Listed in MEDLINE EXECUTIVE EDITOR Tracey L. Giannouris, MA 800-426-9119, ext 52447 | tgiannouris@vetlearn.com MANAGING EDITOR Kirk McKay 800-426-9119, ext 52434 | kmckay@vetlearn.com Subscription inquiries: PUBLISHED BY SENIOR EDITOR 800-426-9119, option 2. Robin A. Henry Subscription rate: $79 for 1 year; $143 for 2 years; $217 800-426-9119, ext 52412 | rhenry@vetlearn.com for 3 years. Canadian and Mexican subscriptions (sur- ASSOCIATE EDITOR face mail): $95 for 1 year; Chris Reilly $169 for 2 years; $270 for 3 800-426-9119, ext 52483 | creilly@vetlearn.com years. Foreign subscriptions (surface mail): $175 for 1 EDITORIAL ASSISTANT Published monthly by Veteri- year; $275 for 2 years; $425 Benjamin Hollis nary Learning Systems, a for 3 years. Payments by 800-426-9119, ext 52489 | bhollis@vetlearn.com division of MediMedia, check must be in U.S. funds 780 Township Line Road, drawn on a U.S. branch of a VETERINARY ADVISER Yardley, PA 19067. Copyright U.S. bank only; credit cards Dorothy Normile, VMD, Chief Medical Officer © 2009 Veterinary Learning are also accepted. Change 800-426-9119, ext 52442 | dnormile@vetlearn.com Systems. All rights reserved. of Address: Please notify Printed in the USA. No part of the Circulation Department SENIOR ART DIRECTOR this issue may be reproduced 45 days before the change in any form by any means Michelle Taylor is to be effective. Send your without prior written permis- 267-685-2474 | mtaylor@vetlearn.com new address and enclose an sion of the publisher. address label from a recent ART DIRECTOR issue. Selected back issues Printed on acid-free paper, David Beagin effective with volume 29, are available for $15 (United 267-685-2461 | dbeagin@vetlearn.com issue 5, 2007. States and Canada) and $17 (foreign) each (plus postage). OPERATIONS Periodicals postage paid at Marissa DiCindio, Director of Operations Morrisville, PA, and at addi- Indexing: Compendium: Con- tinuing Education for Veteri- 267-685-2405 | mdicindio@vetlearn.com tional mailing offices. narians® is included in the Elizabeth Ward, Associate Production Manager–Journals Postmaster: Send address international indexing cover- age of Current Contents/ 267-685-2458 | eward@vetlearn.com changes to Compendium: Agriculture, Biology and Continuing Education for Environmental Sciences (ISI); SALES & MARKETING Veterinarians®, 780 Township SciSearch (ISI); Research Joanne Carson, National Account Manager Line Road, Yardley, PA 19067. Alert (ISI); Focus On: Veteri- 267-685-2410 | Cell 609-238-6147 | jcarson@vetlearn.com Canada Post international nary Science and Medicine publications mail product (ISI); Index Veterinarius Boyd Shearon, Account Manager (Canadian distribution) sales (CAB International, CAB 913-322-1643 | Cell 215-287-7871 | bshearon@vetlearn.com agreement no. 40014103. Abstracts, CAB Health); and Return undeliverable Canadian Agricola (Library of Congress). Lisa Siebert, Account Manager addresses to MediMedia, Article retrieval systems 913-422-3974 | Cell 215-589-9457 | lsiebert@vetlearn.com PO Box 7224, Windsor, ON include The Genuine Article N9A 0B1. Printed in USA. (ISI), The Copyright Clear- CLASSIFIED ADVERTISING ance Center, Inc., University Liese Dixon, Classified Advertising Specialist Compendium: Continuing Education for Veterinarians® Microfilms International, and 800-920-1695 | classifieds@vetlearn.com | www.vetclassifieds.com Source One (Knight-Ridder (ISSN 1940-8307) Information, Inc.). Yearly EXECUTIVE OFFICER author and subject indexes Derrick Kraemer, President for Compendium are pub- lished each December. CUSTOMER SERVICE 800-426-9119, option 2 | info.vls@medimedia.com CompendiumVet.com 97
- 4. March 2009 Vol 31(3) CompendiumVet.com | Peer Reviewed | Listed in MEDLINE EDITORIAL BOARD Anesthesia Internal Medicine Nora S. Matthews, DVM, DACVA Dana G. Allen, DVM, MSc, DACVIM AMERICAN Texas A&M University Ontario Veterinary College BOARD OF Cardiology Internal Medicine and Emergency/ VETERINARY Bruce Keene, DVM, MSc, DACVIM Critical Care PRACTITIONERS North Carolina State University Alison R. Gaynor, DVM, DACVIM (Internal Medicine), DACVECC (ABVP) REVIEW Clinical Chemistry, Hematology, North Grafton, Massachusetts BOARD and Urinalysis Betsy Welles, DVM, PhD, DACVP Nephrology Kurt Blaicher, DVM, DABVP Auburn University Catherine E. Langston, DVM, ACVIM Animal Medical Center (Canine/Feline) Dentistry Plainfield Animal Hospital New York, New York Gary B. Beard, DVM, DAVDC Plainfield, New Jersey Auburn University Neurology Canine and Feline Medicine EDITOR IN CHIEF R. Michael Peak, DVM, DAVDC Curtis W. Dewey, DVM, MS, DACVIM (Neurology), DACVS Douglass K. Macintire, The Pet Dentist—Tampa Bay Veterinary Cornell University Hospital for Animals Eric Chafetz, DVM, DABVP DVM, MS, DACVIM, DACVECC Dentistry (Canine/Feline) Largo, Florida Oncology Vienna Animal Hospital Department of Clinical Sciences Ann E. Hohenhaus, DVM, DACVIM Emergency/Critical Care and Vienna, Virginia College of Veterinary Medicine (Oncology and Internal Medicine) Respiratory Medicine Canine and Feline Medicine Auburn University, AL 36849 Animal Medical Center Lesley King, MVB, MRCVS, DACVECC, New York, New York DACVIM Henry E. Childers, DVM, University of Pennsylvania Gregory K. Ogilvie, DVM, DACVIM DABVP (Canine/Feline) (Internal Medicine and Oncology) Cranston Animal Hospital Endocrinology and Metabolic Disorders CVS Angel Care Cancer Center and Special Cranston, Rhode Island Marie E. Kerl, DVM, ACVIM, ACVECC Care Foundation for Companion Animals University of Missouri-Columbia Canine and Feline Medicine San Marcos, California EXECUTIVE Epidemiology Ophthalmology ADVISORY Philip H. Kass, DVM, MPVM, MS, PhD, David A. Wilkie, DVM, MS, DACVO David E. Harling, DVM, BOARD DACVPM DABVP (Canine/Feline), The Ohio State University University of California, Davis DACVO MEMBERS Parasitology Reidsville Veterinary Hospital Exotics Byron L. Blagburn, MS, PhD Reidsville, North Carolina Avian Behavior Auburn University Canine and Feline Medicine, Thomas N. Tully, Jr, DVM, MS, DABVP Sharon L. Crowell-Davis, (Avian), ECAMS David S. Lindsay, PhD Ophthalmology DVM, PhD, DACVB Louisiana State University Virginia Polytechnic Institute The University of Georgia and State University Jeffrey Katuna, DVM, DABVP Reptiles Douglas R. Mader, MS, DVM, DABVP (DC) Pharmacology Wellesley-Natick Veterinary Dermatology Marathon Veterinary Hospital Katrina L. Mealey, DVM, PhD, DACVIM, Hospital Craig E. Griffin, DVM, Marathon, Florida DACVCP Natick, Massachusetts DACVD Washington State University Canine and Feline Medicine Small Mammals Animal Dermatology Clinic Karen Rosenthal, DVM, MS, DABVP Rehabilitation and Physical Therapy San Diego, California (Avian) Darryl Millis, MS, DVM, DACVS Robert J. Neunzig, DVM, University of Pennsylvania University of Tennessee DABVP (Canine/Feline) The Pet Hospital Wayne S. Rosenkrantz, Feline Medicine Surgery Bessemer City, North Carolina DVM, DACVD Michael R. Lappin, DVM, PhD, Philipp Mayhew, BVM&S, MRCVS, Canine and Feline Medicine Animal Dermatology Clinic DACVIM (Internal Medicine) DACVS Colorado State University Columbia River Veterinary Specialists Tustin, California Compendium is a Vancouver, Washington Margie Scherk, DVM, DABVP (Feline Medicine) C. Thomas Nelson, DVM refereed journal. Articles Nutrition Cats Only Veterinary Clinic Animal Medical Center published herein have Kathryn E. Michel, DVM, MS, DACVN Vancouver, British Columbia Anniston, Alabama been reviewed by at least University of Pennsylvania Gastroenterology Surgery and Orthopedics two academic experts on Debra L. Zoran, DVM, MS, PhD, Ron Montgomery, DVM, MS, DACVS the respective topic and DACVIM (Internal Medicine) Auburn University Surgery Texas A&M University by an ABVP practitioner. Toxicology Elizabeth M. Hardie, Infectious Disease Tina Wismer, DVM, DABVT, DABT Any statements, claims, or product DVM, PhD, DACVS Derek P. Burney, PhD, DVM ASPCA National Animal Poison Control endorsements made in Compendium North Carolina State Gulf Coast Veterinary Specialists Center are solely the opinions of our authors and advertisers and do not necessarily University Houston, Texas Urbana, Illinois reflect the views of the Publisher or Editorial Board. 98 CompendiumVet.com m
- 5. E Each CE article is accredited for 3 contact hours by CE A Auburn University College of Veterinary Medicine. March 2009 Vol 31(3) Features CompendiumVet.com | Peer Reviewed | Listed in MEDLINE 105 Disclosing Medical Errors: Restoring Client Trust ❯❯ Kathleen A. Bonvicini, Daniel O’Connell, and Karen K. Cornell Discussing medical errors with affected clients can ultimately benefit your practice. This article provides tips on creating a protocol for resolving medical errors. 122 Vomiting FREE ❯❯ Héctor J. Encarnación, Joshua Parra, Erick Mears, and Valerie Sadler CE Antiemetic drugs act by affecting neurotrans- mitter–receptor interactions in many areas of the body. Learn why different drugs are used for different causes of vomiting. 133 Squamous Cell Carcinoma FREE ❯❯ Julie L. Webb, Rachel E. Burns, CE Holly M. Brown, Bruce E. LeRoy, and C i E K d Carrie E. Kosarek The authors review the causes, diagnosis, and treatment of this tumor type. Departments Cover image © 2009 Michael Woodruff/Shutterstock.com 100 CompendiumVet.com 102 The Editor’s Desk: Meet Our New Online Understanding Behavior CE “Sister” 116 Feline Hyperesthesia Syndrome ❯❯ Tracey L. Giannouris ❯❯ John Ciribassi 104 Clinical Snapshot The etiology of feline hyperesthesia Pruritus in a Great Dane syndrome can be difficult to determine. ❯❯ Karen A. Moriello Behavior modification and medications 113 Letters may help in treatment. 132 Product Forum Clinical Snapshot 143 Index to Advertisers PAGE 104 143 Market Showcase 143 Classified Advertising Compendium: Continuing Education for Veterinarians® 99
- 6. March 2009 Vol 31(3) WEB EXCLUSIVES CE ARTICLES CLINICAL SNAPSHOT WEB EXCLUSIVE ❯❯ Canine Thoracolumbar Intervertebral ❯❯ Pekinese With Acute Onset of Collapse VIDEOS Disk Disease: Pathophysiology, Neurologic Examination, and Emergency Medical Therapy ❯❯ John F. Griffin IV, Jonathan M. Levine, and Sharon C. Kerwin Thoracolumbar intervertebral disk disease (IVDD) is a common, important cause of paraspinal hyperesthesia, pelvic limb ataxia, paraparesis, NEWS BITES paraplegia, and urinary and fecal incontinence ❯❯ Laparoscopic in dogs. Recent research offers new insights into ❯❯ Vet Study Finds Aggressive Owners Gastropexy the pathophysiology, diagnosis, prognosis, and Have Aggressive Dogs Three videos show some treatment of this disorder. The comparative efficacy A University of Pennsylvania study has found that aspects of the techniques of many familiar therapies remains unknown and most aggressive dogs will remain aggressive when described in the February controversial. This article reviews the pathophysi- dog owners use confrontational or aversive methods 2009 Surgical Views ology and epidemiology of this condition and the to try to train their pets. column, “Laparoscopic- examination and emergency medical therapy of Assisted and Laparoscopic dogs with suspected thoracolumbar IVDD. ❯❯ Economy Means Slowdown for Some Prophylactic Gastropexy: Vet Practices Indications and Techniques.” ❯❯ Canine Thoracolumbar Intervertebral A number of small animal practices have reported a Disk Disease: Diagnosis, Prognosis, drop in client visits. and Treatment ❯❯ New SPCA Vet Hospital a San ❯❯ John F. Griffin IV, Jonathan M. Levine, Francisco Treat Sharon C. Kerwin, and Robert C. Cole The $29-million Leanne B. Roberts Animal Care Thoracolumbar intervertebral disk disease Center is the new home of the San Francisco SPCA’s (IVDD) is a common, important cause of nonprofit veterinary hospital, spay/neuter clinic, and paraspinal hyperesthesia, pelvic limb ataxia, shelter medicine program. paraparesis, paraplegia, and urinary and fecal incontinence in dogs. This article addresses the ❯❯ Beware of Cocoa Mulch diagnosis, prognosis, and treatment of dogs with A popular option for landscaping, cocoa mulch can thoracolumbar IVDD. be deadly to pets. E-NEWSLETTER ❯❯ COMPENDIUM EXTRA Our monthly e-newsletter provides Web Exclusive articles and news, as well as a preview of this month’s journal. Sign up at CompendiumVet.com. CONTACT US ❯❯ Email your questions, suggestions, corrections, or letters to the editor: editor@CompendiumVet.com 100 CompendiumVet.com
- 7. The potential for an animal poison emergency is always there, so we are too. A pill bottle accidently knocked off a sink. Everyday things can quickly become a poison emergency for a pet. It’s the reason the ASPCA® Animal Poison Control Center is here 24/7/365 to support you with critical recommendations. As the only center in North America dedicated solely to animals, we have an experienced team of board certified veterinary toxicologists* on staff with the special expertise needed to save a pet’s life. Our exclusive AnTox™database of more than one million cases of animal poisonings also gives us immediate access to crucial case information. When potential danger turns into a real emergency, don’t hesitate. Call us. ORDER A FREE MAGNET Visit www.aspca.org/freemagnet for your free ASPCA Animal Poison Control Center magnet − an easy way to keep our emergency number handy. For information on our online Toxicology CE courses, visit www.apcc.aspca.org. *American Board of Veterinary Toxicology www.abvt.org No animals were harmed during the production of this ad.
- 8. The Editor’s Desk ❯❯ Tracey L. Giannouris, MA, Executive Editor Tracey with her son, Michael Francis Meet Our New Online CE “Sister” F or more than 30 years, Compendium has 145,000 registered users (43.3% of whom are been your trusted source for continuing practicing veterinarians; 47.7%, veterinary tech- education (CE), both in print and, more nicians; 3%, veterinary technician students; and recently, on the Internet. Now, all of us here 1.2%, veterinary students) visit VetLearn.com. at Compendium are pleased to announce the While there, they investigate a total of 200,000 expansion of our CE efforts with the launch of a pages (40,000 of which are clinical CE review new Web site: CECenter.com. articles) and obtain a total of 2,000 CE credits. CECenter.com, a companion site to VetLearn. Based on these numbers, we saw a clear need to com (which comprises CompendiumVet.com, expand our CE offerings by creating a compan- CompendiumEquine.com, SOCNewsletter.com, ion portal dedicated to “all things CE.” VetTechJournal.com, VeterinaryTherapeutics.com, CECenter.com gives both veterinarians and and ForumVet.com), is devoted exclusively to provid- veterinar y technicians the ability to search ing interactive online CE to veterinarians and veteri- for and participate in CE activities. In addition nary technicians. The mission behind the site is to to the archive of our own peer-reviewed arti- provide veterinary practitioners with new, timely cles, CECenter.com offers exclusive, interactive, information that can be immediately incorporated sponsored courses accredited by the Registry into practice. To achieve this goal, we have gathered of Approved Continuing Education, as well in one central location a wide array of CE activities, as a complete list of CE requirements by state from peer-reviewed CE content from Compendium, and links to CE programs from other respected Compendium Equine, and Veterinary Technician to sources such as the AVMA, the American Animal presentations given by recognized experts. Hospital Association, and accredited universities Our realization of the need for a dedicated and institutions. Other features of CECenter.com veterinary CE portal crystallized with our rec- include a preview of upcoming courses and activ- ognition of the increasing number of veterinary ities. Users get individual accounts that contain a practitioners who are using the VetLearn.com and permanent online record of their CE history and CompendiumVet.com sites to meet CE require- allow them to reprint any CE certificate at any ments. In an average month, approximately time. And our plans call for more CE offerings— and more CE-related features and content—as CECenter.com grows throughout 2009. CECenter.com is accessible to everyone regis- tered on VetLearn.com or CompendiumVet.com, and registration is free. If you haven’t already registered, we invite you to sign up now so that you can explore CECenter—and our other sites—for yourself. We are confident that, along with CompendiumVet.com, CECenter.com will become the preferred online CE source for you and your technician staff. As always, we welcome your feedback, comments, and suggestions for both VetLearn.com and CECenter.com. Please feel free to email me at tgiannouris@vetlearn.com. 102 Compendium: Continuing Education for Veterinarians® | March 2009 | CompendiumVet.com
- 9. LETYOUR LET YOUR SCIENCE CONSCIENCE GUIDE YOU. Milbemycin oxime is trusted #1 by veterinarians for use on their own dogs.1 Veterinarians also believe that INTERCEPTOR® (milbemycin oxime) Flavor Tabs® provide better science and value for the money than Heartgard.2 Dogs and Cats should be tested for heartworm prior to use. In a small percentage of treated dogs, digestive and neurologic side effects may occur. In cats, safety studies at up to 10 times the label dose did not detect any adverse drug reactions. Please see brief summary on page XX for more information. 104 for more information. 1 Milbemycin oxime. Parasiticide Usage Study, June 2005. Data on file. Novartis Animal Health US, Inc. 2 Data on file. Novartis Animal Health US, Inc. ©2009 Novartis Animal Health US, Inc. INTERCEPTOR and Flavor Tabs are registered trademarks of Novartis AG. Heartgard is a registered trademark of Merial Ltd.
- 10. Clinical Snapshot Particularly intriguing or difficult cases Case Presentation #1 TO LEARN MORE ❯❯ Karen A. Moriello, DVM, DACVD, University of Wisconsin-Madison This Great Dane (A) was one of 12 border collies and seven cats in addi- Clinical Snapshot presents illustrated dogs in a kennel, all of which had had tion to these dogs. What are the treat- case histories and challenges you to intense pruritus for 1 year. The owners ment options for this kennel of dogs? answer the questions posed. This case reported that the other dogs looked 3. A similarly named condition occurs is part of the series of Self-Assessment similar and that all the dogs were los- in cats. What is the cause, and what Colour Review books on multiple topics ing weight and were irritable with the treatment can be used for this from Manson Publishing Ltd., London, available from Blackwell Publishing owners and each other. Close examina- condition? Professional. tion of the skin revealed a generalized SEE PAGE 114 FOR ANSWERS AND EXPLANATIONS. papular eruption without evidence of For more information or to obtain any of the pustules or epidermal collarettes. Any A books in the series, call 800-862-6657 manipulation of the skin triggered an or visit BlackwellProfessional.com intense episode of self-mutilation. All the dogs were currently vaccinated and B received monthly heartworm medica- tion and monthly spot-on flea control. The owners reported no lesions or dis- comfort after handling the dogs. Flea combings were negative. Skin scrap- ings revealed the organism shown (B). 1. What is the diagnosis? 2. The owners of the kennel have three INTERCEPTOR Flavor Tabs are palatable and most often will be consumed by the dog or cat when offered by the owner. As an alternative, the dual-purpose tablet may be offered in food or administered as other tablet medications. Watch the dog or cat closely following dosing to be sure the entire dose has been consumed. If it is not entirely consumed, redose once with the full recommended dose as soon as possible. INTERCEPTOR Flavor Tabs must be administered monthly, preferably on the same date each month. The first dose should be administered within one month of the dog or cat’s first exposure to mosquitoes and monthly thereafter until the end of the mosquito season. If a dose is missed and a 30-day interval between dosing is exceeded, administer INTERCEPTOR Flavor NADA 140-915, Approved by FDA Tabs immediately and resume the monthly dosing schedule. INTERCEPTOR® (milbemycin oxime) Flavor Tabs® for Dogs and Cats If INTERCEPTOR Flavor Tabs replace diethylcarbamazine (DEC) for heartworm prevention in dogs, the first dose must be Brief Summary—For full product information see product insert. given within 30 days after the last dose of DEC. Caution: Federal (USA) law restricts this drug to use by or on the order of a licensed veterinarian. Warnings: Not for human use. Keep this and all drugs out of the reach of children. Indications and Usage: INTERCEPTOR Flavor Tabs for dogs are indicated for use in the prevention of heartworm disease Precautions: caused by Dirofilaria immitis, the control of adult Ancylostoma caninum (hookworm), and the removal and control of adult Dogs: Do not use in puppies less than four weeks of age and less than two pounds of body weight. Prior to initiation of the Toxocara canis and Toxascaris leonina (roundworms) and Trichuris vulpis (whipworm) infections in dogs and in puppies INTERCEPTOR Flavor Tabs treatment program, dogs should be tested for existing heartworm infections. Infected dogs four weeks of age or greater and two pounds body weight or greater. INTERCEPTOR Flavor Tabs are indicated for use should be treated to remove adult heartworms and microfilariae prior to initiating treatment with INTERCEPTOR Flavor Tabs. in the prevention of heartworm disease caused by Dirofilaria immitis, and the removal of adult Ancylostoma tubaeforme Mild, transient hypersensitivity reactions manifested as labored respiration, vomiting, salivation, and lethargy may occur (hookworm) and Toxocara cati (roundworm) in cats and kittens six weeks of age or greater and 1.5 lbs. body weight or after treatment of dogs carrying a high number of circulating microfilariae. greater. Cats: Do not use in kittens less than six weeks of age or less than 1.5 lbs. body weight. Safety in heartworm positive cats has Dosage and Administration: not been established. Safety in breeding, pregnant, and lactating queens and breeding toms has not been established. Dogs: INTERCEPTOR Flavor Tabs for Dogs are given orally, once a month, at the recommended minimum dosage rate of 0.23 mg milbemycin oxime per pound of body weight (0.5 mg/kg). Adverse Reactions: The following adverse reactions have been reported following the use of INTERCEPTOR in dogs: depression/lethargy, vomiting, ataxia, anorexia, diarrhea, convulsions, weakness, and hypersalivation. Recommended Dosage Schedule for Dogs Body Weight INTERCEPTOR Flavor Tabs Efficacy: 2–10 lbs. One tablet (2.3 mg) Dogs: INTERCEPTOR Flavor Tabs eliminate the tissue stage of heartworm larvae and the adult stage of hookworm 11–25 lbs. One tablet (5.75 mg) ( Ancylostoma caninum), roundworms ( Toxocara canis, Toxascaris leonina ), and whipworm ( Trichuris vulpis) infestations 26–50 lbs. One tablet (11.5 mg) when administered orally according to the recommended dosage schedule. 51–100 lbs. One tablet (23.0 mg) Cats: INTERCEPTOR Flavor Tabs for Cats eliminate the tissue stage of heartworm larvae and hookworm (Ancylostoma Dogs over 100 lbs. are provided the appropriate combination of tablets. tubaeforme ) and roundworm ( Toxocara cati ) infections when administered orally according to the recommended dosage schedule. Cats: INTERCEPTOR Flavor Tabs for Cats are given orally, once a month, at the recommended minimum dosage rate of 0.9 mg milbemycin oxime per pound of body weight (2.0 mg/kg). For technical assistance or to report suspected adverse events, call 1-800-332-2761. Recommended Dosage Schedule for Cats Manufactured for: Novartis Animal Health US, Inc. Body Weight INTERCEPTOR Flavor Tabs Greensboro, NC 27408, USA 1.5–6 lbs. One tablet (5.75 mg) ©2008 Novartis Animal Health US, Inc. 6.1–12 lbs. One tablet (11.5 mg) 12.1–25 lbs. One tablet (23.0 mg) INTERCEPTOR and Flavor Tabs are registered trademarks of Novartis AG. Cats over 25 lbs. are provided the appropriate combination of tablets. NAH/INT-FT/BS/5 06/08 104 Compendium: Continuing Education for Veterinarians® | March 2009 | CompendiumVet.com
- 11. ©2009 Monkey Business Images/Shutterstock.com Disclosing Medical Errors: * Restoring Client Trust ❯❯ Kathleen A. Bonvicini, T he purpose of this article is to help Your nephew says, “I feel terrible—what EdD, MPHa veterinarians reach a mutually satis- should I tell my clients?” Institute for Healthcare fying resolution with clients when Communication individual, team, or system errors result in How would you respond? What one New Haven, Connecticut an adverse outcome. It offers a model that piece of advice would you give to your integrates the ethics of veterinary medi- nephew? ❯❯ Daniel O’Connell, PhDa Institute for Healthcare cine with specific skills and attitudes that Communication have been shown to promote psychologic Ethics, Values, and Moral Compass Seattle, Washington and practical resolution of these situations In examining this scenario and consid- for clients and veterinary practices. ering your own opinions, you are likely ❯❯ Karen K. Cornell, DVM, relying on the values that guide the way PhD, DACVS Case Scenario you practice veterinary medicine. Still, this The University of Georgia Consider the following1: will be a very tough conversation to have. Athens, Georgia Many clinicians report feelings of shame, Your nephew, a recent veterinary school heartbreak, and vulnerability in situations graduate who is newly employed at a pri- like this one. Our natural instinct for self- vate small animal hospital, calls you for preservation, coupled with advice we may advice. Four days ago, he admitted a dog have received previously, can tempt us to At a Glance to the hospital for vaccinations and board- be very guarded when talking with clients Case Scenario ing. During the admission process, he about adverse outcomes and to use cal- Page 105 administered a Bordetella bronchiseptica culated omissions and rationalizations to Ethics, Values, vaccine to the dog. The dog died this morn- conceal evidence of an error. In the above and Moral Compass ing. In retrospect, your nephew realizes scenario, one might argue that vaccination Page 105 that he picked up a syringe of intranasal has inherent risks. A frightened young vet- Disclosure and Resolution: B. bronchiseptica vaccine that still had a erinarian might be attracted to such seduc- A Protocol needle on it from being drawn from the tive reasoning as, “Disclosing the actual Page 106 vial, then gave the vaccine subcutaneously. cause of death will increase the clients’ dis- This inappropriate route of administration tress and certainly will not bring back the What to Do When resulted in the development of liver failure animal. What good could come from tell- an Error Occurs Page 108 while the dog was boarded at the hospital. ing the clients what really happened?” Guidelines for Disclosure *Adapted with permission from Compendium Page 110 Rationale for Openness Equine 2008;3(1):14-22. a The ethical positions of organizations such Establish Practice Protocol Drs. Bonvicini and O’Connell disclose that their nonprofit foundation receives funding as the American Medical Association,2 the Page 112 from Bayer Animal Health. American College of Physicians,3 and the CompendiumVet.com | March 2009 | Compendium: Continuing Education for Veterinarians® 105
- 12. Disclosing Medical Errors: Restoring Client Trust Joint Commission4 have clear statements that clude, and explain than the practice where the require accurate disclosure of adverse medi- adverse event took place? cal outcomes in human medicine. Similar ethi- Most client disappointments with veterinary cal positions exist in veterinary medicine.5 outcomes are not the result of negligent care. Research in human medicine and other pro- For instance, clients may have unreasonable fessions6–10 has described the potential advan- expectations that were not adequately addressed tages of a more open approach with patients, or corrected. They may not appreciate the vari- families, and “customers” in these situations. ability between animals or that diagnostic and When applied to veterinary medicine, these treatment plans are based on probabilities rather benefits include the following: than certainties. The clinical picture may change as additional signs emerge and the response to More situations can be worked out directly treatment is assessed.15 Almost every effective between the veterinarian, the client, and the treatment brings with it the potential for untow- insurance carrier without stimulating legal ard side effects and complications. Unless clients action or formal complaints to licensing boards. are apprised of these risks, they may mistakenly The AVMA Professional Liability Insurance believe that similarly trained clinicians would Trust (PLIT) recommends that veterinarians have been able to solve the problem more quickly, call the PLIT office as soon as possible after an with less suffering, and at a lower cost. Each of event that could give rise to a claim.b the above factors is a reminder of the importance Rebuilding rapport and trust and resolving of obtaining true owner consent, recognizing disagreements can turn initial client disap- and correcting unreasonable expectations, and QuickNotes pointment into an even stronger relationship. offering adequate explanations when diagnosis When the practice and the insurance carrier are and treatment are unsuccessful, even when the Most client disap- willing to initiate discussion of fair settlements standard of care is met.16 pointments with with clients who have been legitimately affected veterinary outcomes by errors in practice, the dollar amounts tend Errors and Harm in Veterinary Medicine are not the result of to be easier to negotiate and more reasonable While research into the incidence, type, and negligent care. than those obtained through legal action7,8,11 impact of errors in veterinary medicine is limited, because client bitterness is minimized and dol- it is clear that adverse events related to errors do lar amounts are focused on reasonable com- occur. For instance, one small UK study17 found pensation rather than punishment. that 78% of recent practicing veterinary gradu- ates surveyed reported they had made a mistake Adverse Outcomes and Medical Errors that resulted in a less-than-optimal or potentially Adverse outcome is the term used in veterinary adverse outcome for a patient. Most mistakes and human medicine to indicate unanticipated involved failure to conduct appropriate diagnostic harm that results from a medical treatment tests, surgical mistakes during procedures other rather than from a disease or condition itself.12 than neutering, and administration of inappro- An ethical approach to disclosure of harm priate drugs or medical treatment. Forty percent hinges on the veterinarian’s commitment to reported that they had not discussed the error determining and then sharing the most accurate with the client. These mistakes caused many of conclusions about how the harm was caused. the respondents considerable distress. While sometimes fairly clear, many situations require the veterinarian to draw a bright line Disclosure and Resolution: A Protocol through a gray situation to determine whether Research has consistently indicated that, in a breach of the standard of care caused the human medicine, patients and families typically harm (and, therefore, the harm was prevent- want to hear the following from the care provider able) or whether the harm occurred in the con- when an adverse event or outcome occurs10,18–21: text of care that most veterinarians would judge as reasonable in a similar instance.13,14 Practically What happened and emotionally, this can be difficult to do, yet How it happened who is in a better position to investigate, con- What the immediate medical consequences are, and what impact they will have on b Ellis LJ. Personal communication, AVMA PLIT, 2007. quality of life 106 Compendium: Continuing Education for Veterinarians® | March 2009 | CompendiumVet.com
- 13. ®
- 14. Disclosing Medical Errors: Restoring Client Trust What can be done now and heartbreak for the patient’s and client’s How the problem will be prevented in the situation may leap to self-blame too quickly, future (i.e., the promise that something good only to have the investigation determine that will come from the adverse event) no deviation from the standard of care was An apology if appropriate (if errors led to implicated in the outcome. There is usually the harm) enough time to consult with a trusted col- league to clarify your thinking and reestablish The following protocol (summarized in BOX 1) your emotional equilibrium before needing to provides specific approaches to assist you in make a full explanation to a client about how organizing a thorough, appropriate, construc- an adverse outcome arose. tive response that meets the needs of the patient and the expectations of clients and Investigate the details of the event. that restores clients’ trust, regardless of the Develop clarity about what happened. The severity of the adverse event. client is entitled to the most accurate under- standing of what happened, which may take Tend to the patient’s immediate clinical some time and investigation to clarify. You care. can ask for the client’s patience while you In the event of an adverse outcome, the pri- investigate. Make—and keep—a clear prom- mary responsibility of the veterinarian is to ise to discuss the conclusions when they are address the needs of the patient and, if appro- reached. In many cases, the cause of the harm priate, obtain medical consultation or arrange is never fully determined; however, it remains for necessary follow-up. Consider that charges the veterinarian’s responsibility to disclose QuickNotes for services in these circumstances may not the most likely causal pathway. Determining Emotional self- be billable if they are addressing conditions whether error was the cause of harm should awareness is key caused by errors (including equipment fail- be guided by asking,22 “What would have been to adopting the most ures and system or procedural mistakes that expected of a similarly trained individual in constructive attitude caused harm). that situation?” and behavior. Address your own emotions and needs. Prepare for discussion with the client. Emotional self-awareness is key to adopting Start by trying to imagine and anticipate what the most constructive attitude and behavior. A the client may be thinking and feeling when clinician who is flooded with worries about hearing the news. O’Connell and Reifsteck23 potential complaints and possible malpractice suggest asking yourself the following self- suits may be unconsciously pushed to mini- reflection questions to help guide you in your mize or even distort the facts and explana- discussion with the client: tion offered to the client. On the other hand, the clinician who is overwhelmed with guilt What is the most accurate explanation for the BOX 1 adverse event? How would I want the situation to be han- What to Do When an Error Occurs dled if I were in the client’s position? 1. Care for the patient. How would I feel if I suspected or later learned that the provider had not been forthright with 2. Compose yourself and investigate the ©2009 Phase4Photography/Shutterstock.com details of the event. me about the injury and its causes? 3. Disclose to the client what occurred and It is helpful to rehearse the actual words you apologize, if appropriate. will use in explaining the adverse event because 4. Discuss with the client the hearing them will help you determine whether plan of care for the animal. they are likely to be adequate to address the cli- 5. Be accountable and discuss ent’s expected thoughts and feelings. methods of reparation. Consider carefully who should attend the 6. Share how you plan to disclosure conversation. The veterinarian who keep this from happening is primarily responsible for the care of the in the future. animal should be there and take the lead in 108 Compendium: Continuing Education for Veterinarians® | March 2009 | CompendiumVet.com
- 15. 1 antidote In a poison emergency, trust ToxiBan. ® There’s a reason ToxiBan has been the number one selling poison treatment for more than 30 years. When it comes to emergencies, trust your patients’ lives to the poison treatment that has become the industry gold standard. Trust ToxiBan. 50+ • Recommended by the ASPCA Animal Poison Control Center and many other organizations • Three dosing options: granules, suspension and suspension with sorbitol • Sorbitol acts as a mild cathartic poisons When your patients’ lives are in your hands, make sure ToxiBan is on your shelf. 1,000,000+ animals treated
- 16. Disclosing Medical Errors: Restoring Client Trust the discussion, even if the adverse event was Elicit and acknowledge client reactions. primarily caused by another staff member’s Frequently throughout the discussion, you actions. The presence of a person who was should solicit the client’s perspective through not directly involved with the adverse event questions and statements such as, “What and who has credibility, maturity, and strong thoughts or questions do you have about communication skills, such as the practice what I have explained so far?” and “I imag- manager, can help facilitate and mediate what ine you have many emotions and questions, can be a difficult conversation. Plan when and and I want to hear from you first before going how to begin the discussion. An initial discus- on.” Eliciting reactions serves to validate the sion with the client should take place as soon client’s perspective on the medical error and as possible after the adverse event. adverse outcome and sets the stage for effec- tive interaction. Disclose to the client what occurred and Voice tone and body language are as apologize. important as actual words in conveying empa- Disclose what you know, but guard against thy for the client’s experience. Showing your premature conjecture until you are as certain “human side” through genuine expressions of as you can be about causes and consequences. empathy can strengthen the bond and trust When possible, make an initial phone call to between you and your client. An empathetic set up an in-person meeting rather than have veterinarian is not defensive, even when a cli- the discussion over the phone. If a phone dis- ent expresses anger and makes accusations. closure cannot be prevented, start the discus- Acknowledging the client’s reaction as a legiti- sion by acknowledging how sorry you are to mate one by making a statement such as, “It is QuickNotes have to be sharing the news over the phone. normal to feel shocked and angry to learn that Disclose what you In person, start the discussion by offering a something like this has happened,” does not know, but guard frame for the information to follow: indicate that you agree with the conclusions against premature that prompted it. conjecture until “I have some difficult news to share with you. I’m very sorry to have to tell you…” Apologize appropriately. you are as certain After an adverse event or outcome, the proper as you can be Then explain the situation by addressing type of apology can have a powerful effect about causes and each of the issues listed above. BOX 2 offers on the client, making him or her less angry consequences. some additional guidelines to approaching the and suspicious. There are two types of apol- disclosure conversation. ogy: an apology of sympathy and an apology of responsibility. An apology of sympathy is: BOX 2 Guidelines for Disclosure “I’m sorry this happened to you and your pet.” 1. Choose a quiet place. An apology of responsibility is: 2. Ensure that there will be no distractions (e.g., turn cell phones and pagers off). 3. Provide a warning (e.g., “ I have difficult “I am terribly sorry for this error we made news to share.”). that has caused more problems for your pet.” 4. Be attentive to your own and your client’s nonverbal messages. Mazor and colleagues6,24 demonstrated that ❯ Make eye contact. in situations in which a breach of the standard ❯ Sit at the client’s level. of care caused harm, respondents reported ❯ Respond appropriately to client nonverbal more trust and satisfaction and less likelihood cues (e.g., “I see that this is shocking to you. of changing doctors when they received full Should I go on or do you need a moment?”). disclosure with an apology of responsibility. 5. Facilitate discussion and encourage questions. In instances in which an adverse event is not 6. Finish with a plan for the next contact. the result of medical error, an apology of sym- pathy is appropriate. 110 Compendium: Continuing Education for Veterinarians® | March 2009 | CompendiumVet.com
- 17. Disclosing Medical Errors: Restoring Client Trust Discuss the plan for care of the animal. come from the harm they have experienced. In many instances, by the time the disclosure It is unacceptable to clients to think that a conversation takes place, steps have already veterinarian’s failure to change or reflect on been taken to care for the animal, and the the incident means that others are likely to veterinarian is thinking about other poten- suffer similarly.23 These sentiments become tial consequences of the error. However, it is expressed as complaints to licensing boards important to remember that the client has just as well as malpractice suits. Therefore, the vet- received the news. Discuss the recommended erinarian’s goal is to convey to the client that plan for continuing care of the animal, includ- he or she has learned everything that can be ing the potential short- and long-term out- learned from the adverse event: comes. Often, clients are unclear about what lasting effect the error will have on their pet “I can promise you that we’ll all be meeting and may not comprehend the gravity or—in later today to review every step of our proce- some cases—the limited impact of the error. It dures. We want to immediately change any- is critical that immediate concerns as well as thing that makes it more likely that this could the potential long-term impact be discussed in happen again to any other animal in our a manner the client understands. care.” Be accountable and offer reparation. Don’t rush. Finally, the practice must acknowledge respon- Keep in mind that all these elements of dis- sibility to help the client recover as much as closure may take more than one meeting or possible from the harm that has been caused. conversation to deliver effectively to the client. QuickNotes Appropriate fees for the animal’s care should Discussion of reparation may take the longest The heart of all be waived. The veterinarian should anticipate to resolve in cases in which the impact of the effective and ethical discussion of who will pay for follow-up care harm on the surviving animal and the extent disclosure is to before the disclosure conversation. Again, the of needed ongoing treatment are uncertain. AVMA PLIT recommends that it be contacted However, if a client has suffered serious loss provide the client early on to discuss how best to approach this or even financial harm (e.g., economic impact with an accurate situation. on a breeding kennel), he or she is going to understanding of Being accountable and willing to make rep- want to promptly hear that you (with your what has happened. arations is crucial in the disclosure process; liability carrier’s guidance) intend to offer fair however, it does not mean immediately offer- compensation. ing money. Rather, it means opening up the The heart of all effective and ethical disclo- conversation: sure is to provide the client with an accurate “Can we do more to resolve this with you? understanding of what has happened. The We stand ready to do what we can to help you form an apology takes and the offers made to recover from this as much as possible.” help a client recover from an injury caused by According to the Sorry Works! Coalition,25 a medical error should flow naturally from the leading advocacy organization for disclosure veterinarian’s own understanding of his or her after adverse medical events, paying for errors degree of responsibility for the injury. is the ethical thing to do. However, there may be a fear that it will appear as if you are “buy- Summary ing” clients off. This is an understandable con- Consider your recommendations to your cern. In veterinary medicine, all of the steps nephew in the scenario at the start of this col- of disclosure—admission of error, explanation, umn. Ask yourself the following questions: Are apology—can still be delivered sincerely, and my recommendations based on ethical stan- PLIT or your liability carrier can be consulted dards of openness, transparency, and integ- on how to offer reparation. rity? Would I be satisfied if I were the client? Despite our best efforts, animals will occasion- Describe plans to fi x the behavior or sys- ally be harmed by problems that occur while tem that contributed to the harm. they are in our or our staff’s care. Having a Consumers who are affected by a medical standard approach to disclosure and resolu- error want to know that something good has tion that is consistent with our values, despite CompendiumVet.com | March 2009 | Compendium: Continuing Education for Veterinarians® 111
- 18. Disclosing Medical Errors: Restoring Client Trust BOX 3 tate to embrace such openness for fear that it may increase malpractice risk. Acknowledging Establish Practice Protocol l errors has been evaluated positively, leading to increased trust and lessening the possibility of ©2009 Sarah Salmela/Shutterstock.com How will the practice handle an error? negative impact7; however, clinicians may still Who will discuss it with the client? worry about the potential costs of openness Who will be present during the discussion? n? ? and transparency. Although disclosure discus- Will individuals involved be identified? sions are difficult and may still result in formal What time frame do we recommend? Where is the contact information for our complaints and malpractice suits, evidence8 liability carrier? tells us that acknowledging errors can signifi- When and how will we discuss this with cantly reduce litigation costs, reduce bitterness staff members? and mistrust, and avoid unnecessarily lengthy legal proceedings with the accompanying emo- tional pain for consumers and clinicians alike. the fears and vulnerabilities we are likely to We encourage all veterinarians, whether feel at these times, can help us earn our cli- joining a practice or established in one, to ents’ forgiveness and enable us to forgive our- engage in conversations with their colleagues selves. BOX 3 lists some questions to ask when about the practice’s approach to and protocol developing a disclosure protocol. for disclosure discussions in the event of a We believe in using ethical standards and medical error. In addition, it is crucial to con- values of openness and honesty as a spring- sult your malpractice liability insurance carrier board for conversations about medical errors. to establish its position on the management of However, many veterinary practices may hesi- disclosure and resolution. References 1. Greene CE, Schulz RD. Immunoprophylaxis. In: Greene CE, ed. cessed January 2009 at www.nymc.edu/fammed/medicalerrors.pdf. Infectious Diseases of the Dog and Cat. St. Louis: Elsevier Saun- 13. Nunalee MM, Weedon GR. Modern trends in veterinary mal- ders; 2006:1097. practice: how our evolving attitudes toward non-human animals 2. Council on Ethical and Judicial Affairs. Code of Medical Eth- will change veterinary medicine. Animal Law 2004;10:125-161. ics—Current Opinions, 2006–2007 Edition. Chicago: American Accessed January 2009 at www.animallaw.info/journals/jo_pdf/ Medical Association; 2006. vol10_p125.pdf. 3. American College of Physicians. Ethics Manual. 5th ed. Ann 14. Wilson JF. Limited legal liability in zoonotic cases. NAVC Clin Intern Med 2005;142:560-582. Accessed January 2009 at www. Brief May 2005. Accessed January 2009 at www.cliniciansbrief. acponline.org/ethics/ethicman5th.htm. com/?p=articles&newsid=678. 4. Joint Commission on Accreditation of Healthcare Organiza- 15. O’Connell D, Bonvicini KA. Addressing disappointment in veterinary tions. 2006 Comprehensive Accreditation Manual for Hospitals: practice. Vet Clin North Am Small Anim Pract 2007;37(1):135-149. The Official Handbook. Oakbrook Terrace, IL: Joint Commission 16. Bonvicini KA. Are clients truly informed? Communication tools Resources; 2005. and risk reduction. Compend Equine 2007;2(2):74-80. 5. American Veterinary Medical Association. Principles of Veteri- 17. Mellanby RJ, Herrtage ME. Survey of mistakes made by recent nary Medical Ethics. 2003. Accessed January 2009 at www.avma. veterinary graduates. Vet Rec 2004;155:761-765. org/issues/policy/ethics.asp. 18. Liebman CB, Hyman CS. A mediation skills model to man- 6. Mazor KM, Simon SR, Yood RA, et al. Health plan members’ views age disclosure of errors and adverse events to patient. Health Aff about disclosure of medical errors. Ann Intern Med 2004;140(6):409- 2004;23:22-32. 418. 19. Witman AB, Park DM, Hardin SB. How do patients want physi- 7. Kraman S, Hamm G. Risk management: extreme honesty may cians to handle mistakes? A survey of internal medicine patients in be the best policy. Arch Intern Med 1999;131:963-967. an academic setting. Arch Intern Med 1996;156:2565-2569. 8. Boothman R. Apologies and a strong defense at the University 20. Lazare A. Apology in medical practice: an emerging clinical skill. of Michigan Health System. Physician Exec 2006;32(7):7-10. JAMA 2006;296(11):1401-1404. 9. American Society for Healthcare Risk Management. Disclosure 21. Blendon RJ, DesRoches CM, Brodie M, et al. Views of prac- of Unanticipated Events: The Next Step in Better Communication ticing physicians and the public on medical errors. N Engl J Med with Patients. Chicago: American Society for Healthcare Risk Man- 2002;347(24):1933-1940. agement; 2003. 22. Reason J. Human Error. New York: Cambridge University Press; 10. Schneider B, Bowen DE. Understanding customer delight and 1990. outrage. Sloan Manage Rev 1999;41(1):35-45. 23. O’Connell D, Reifsteck SW. Disclosing unexpected outcomes 11. COPIC Insurance Company. A success story. COPIC’s 3Rs and medical error. J Med Pract Manage 2004;19(6):317-323. Program Newsletter 2007;4(2). Accessed January 2009 at www. 24. Mazor KM, Simon SR, Gurwitz JH. Communicating with pa- callcopic.com/resources/custom/PDF/3rs-newsletter/vol-4-iss-2- tients about medical errors: a review of the literature. Arch Intern oct-2007.pdf. Med 2004;164:1690-1697. 12. Halbach JL, Sullivan L. Medical Errors and Patient Safety: A Curricu- 25. Question and answer. Sorry Works! Coalition Newsletter; De- lum Guide for Teaching Medical Students and Family Practice Residents. cember 4, 2006. Accessed January 2009 at www.sorryworks.net/ New York Medical College, Department of Family Medicine; 2003. Ac- newsletter20061204.phtml. 112 Compendium: Continuing Education for Veterinarians® | March 2009 | CompendiumVet.com
- 19. Letters Five Common Toxins and Activated Charcoal I have a question for the author about his re- search for the November 2008 Pharm Profile article, “Activated Charcoal.” The article states Pharm Profile that charcoal is contraindicated for metalde- Activated Charcoal hyde ingestion. Yet it is widely accepted that it Lotfi El Bahri, DVM, MSc, PhD École Nationale de Médecine Vétérinaire Sidi Thabet, Tunisia is proper protocol to give activated charcoal in Indication: Emergency treatment of acute poisoning after ingestion of a large amount of toxin or drug. Activated charcoal—also known as active carbon, activated carbon, adsorbent charcoal, these cases. In fact, in the article “Five Com- medicinal charcoal, or carbo medicinalis1—is a carbon residue derived from vegetable material (e.g., wood pulp). It is produced by exposing the original material to an oxi- dizing gas compound of steam, oxygen, and acids at high temperatures (900°C). This activation process creates a network of fine pores (10 to 20 nm in size) in the result- ing charcoal.2 The result is a highly porous material with an enormous surface area relative to its weight.3 The adsorptive capacity of activated charcoal is a function of mon Toxins Ingested by Dogs and Cats” in the its binding surface area. In commercial products, the surface area varies from 1000 to 2000 m2 per gram.3,4 PHARMACOKINETICS Activated charcoal comes as a very fine, porous, black powder or granules measuring same issue, charcoal is recommended as an less than 1.0 mm in diameter. It does not contain any gritty material.2 It is insoluble in water and all usual solvents.1 Activated charcoal is not absorbed in the gastrointestinal tract, and all ingested activated charcoal is excreted in the feces.1 It is a stool marker, indicating that the toxin has passed through the gastrointestinal tract and no further significant toxin absorption from the original ingestion will occur. antidote to help eliminate metaldehyde. I am PHARMACOLOGY Owing to its large surface area, activated charcoal can adsorb many drugs and toxins (e.g., acetaminophen, salicylates, digoxin, organophosphate and carbamate insecticides, pyrethrins and pyrethroids, anticoagulant rodenticides, strychnine) in the upper gas- trointestinal tract.1–3 It thereby facilitates the excretion of the adsorbed toxicant in the curious about the discrepancy. Also, I was wondering if there is any Pharm Profile focuses on new drugs or indications in the veterinary market as well as feces and reduces the amount of free agent available for absorption into the blood- stream. Activated charcoal maintains its attachment to toxins through covalent binding and van der Waals forces.5 Adsorption of substances onto charcoal is a reversible process, with rapid adsorption pharmacologic products of high and slow desorption. Optimal adsorption occurs when the ratio of charcoal to toxin is research on UAA gel, which is mentioned in the Pharm Profile article. interest to practitioners. Send comments/questions via email to editor@CompendiumVet.com 10:1 or higher.6 Administration of activated charcoal can lead to a 30% to 40% drop in digoxin levels within 12 to 18 hours.7 In one canine study, oral administration of acti- vated charcoal solution (2.5 g/kg) 30 minutes after a single oral dose of carprofen (16 mg/kg) effectively decreased the maximum plasma carprofen concentration (85.9 ± or fax 800-556-3288. 11.9 mg/L to 58.1 ± 17.6 mg/L) by decreasing carprofen absorption in the gastroin- testinal tract.8 Elimination of substances that undergo enterohepatic recirculation (e.g., Angela LeBrun, CVT Visit CompendiumVet.com for full-text articles, CE testing, and CE test answers. NSAIDs, theobromine, cholecalciferol, tetrahydrocannabinol) may be enhanced by repeated oral doses of activated charcoal.1,3 Puget Sound Veterinary Referral Center & Animal Emergency Clinic, Tacoma, Washington COMPENDIUM 596 November 2008 I have just finished reading the November tains activated hardwood charcoal and viously. Activated charcoal and a saline 2008 journal and am puzzled by the thermally activated attapulgite clay in cathartic may be given, although [ethyl- contradiction between the paper by Drs. an aqueous gel suspension. The recom- ene glycol] is not significantly adsorbed Luiz and Heseltine and that by Dr. El mended oral dosage is 1 to 3 mL/kg in by charcoal.” I verified this information Bahri in reference to the effectiveness dogs, cats, and large animals. The manu- with the sources cited in the article.1,2 of activated charcoal in the treatment of facturer states that the product should I also gathered information from the ethylene glycol and metaldehyde poison- be shaken well before use and protected sixth edition of Ettinger’s Textbook of ings. The former says to use it; the latter from freezing. Veterinary Internal Medicine,3 which says it’s ineffective. Is there an explana- Lotfi El Bahri, DVM, MSc, PhD states to administer activated charcoal tion as to the correct information? for recent exposure (≤2 hr). The recom- References Philip T. Durfee, DVM, MPH, MVSc 1. Buck WB, Osweiler GD. Metaldehyde. In: Van Gelder mendation we stated is conditional on GA, ed. Clinical and Diagnostic Veterinary Toxicology. the duration of exposure. 2nd ed. Dubuque, IA: Kendall/Hunt Publishing Compa- The Authors’ Replies ny; 1976:227-228. For metaldehyde, we wrote, “If the The administration of activated charcoal 2. Andreasen JR Jr. Metaldehyde toxicosis in duck- patient presents acutely, is alert, and in the treatment of metaldehyde intoxi- lings. J Vet Diagn Invest 1993;5:500-501. does not have excessive muscle tremors 3. Booth NH, McDonald LE, eds. Veterinary Pharma- cation is controversial. Several references cology and Therapeutics. 5th ed. Ames: The Iowa State or seizures, an emetic should be given, I consulted do not either include1,2 or University Press; 1982:1013-1014. followed by activated charcoal and a 4. Campbell A. Metaldehyde. In: Campbell A, Chap- recommend3,4 the administration of acti- man M, eds. Handbook of Poisoning in Dogs and Cats. cathartic.” Again, I verified this statement vated charcoal in the treatment of met- Oxford: Blackwell Science; 2000:181-185. with the sources cited in the article4,5 as aldehyde intoxication. The Handbook 5. Shintani S, Goto K, Endo Y, et al. Adsorption effects well as The 5-Minute Veterinary Consult of activated charcoal on metaldehyde toxicity in rats. Vet of Poisoning in Dogs and Cats, which Hum Toxicol 1999;41(1):15-18. by Tilley,6 which recommends emetics is considered a veterinary toxicology or gastric lavage followed by adminis- reference, states, “Metaldehyde report- I double-checked our sources about the tration of activated charcoal to prevent edly does not bind to activated charcoal use of activated charcoal in ethylene gly- further absorption in animals with no and therefore use of adsorbents is not col and metaldehyde toxicoses. For eth- clinical signs. indicated.”4 On the other hand, activated ylene glycol, we wrote, “Early diagnosis Julie Ann Luiz, DVM charcoal has been shown to help inhibi- and treatment are critical for a successful References tion of metaldehyde absorption in rats.5 outcome. Emetics should be adminis- 1. Osweiler GD. Common household products. In: Nie- Universal Animal Antidote (UAA) gel tered if no signs are observed and the ginski EA, ed. The National Veterinary Medical Series: (Vedco, Inc. St. Joseph, Missouri) con- exposure occurred less than 4 hours pre- CONTINUES ON PAGE 114 CompendiumVet.com | March 2009 | Compendium: Continuing Education for Veterinarians® 113
- 20. Clinical Snapshot Answers and Explanations Case Presentation #1 A B SEE PAGE 104 FOR CASE PRESENTATION. ity (e.g., tremors, salivation) 1. Scabies infestation. The organism within 24 hours, I administer is a Sarcoptes egg. One mite or egg a full treatment dose of 200 is diagnostic for scabies. Definitive μg/kg PO the next day. evidence of a scabies infestation Herding breeds of dogs, (eggs or mites) is not always found, especially collies, are known to 3. Canine scabies is not considered con- even in “classic cases.” Most dogs be sensitive to ivermectin. Thus, tagious to cats. However, Sarcoptes with scabies are diagnosed based this drug is best avoided in collies. mites have been reported in a small on response to treatment; therefore, Dogs sensitive to ivermectin can number of cats with severe debilita- if scabies is suspected, it should be often tolerate milbemycin oxime tion and in pruritic cats in England. treated accordingly. at 3 mg/kg PO weekly for 3 to 6 There may be some geographic varia- 2. Scabies mites can live for a short weeks. Lime sulfur dips are also tion with respect to contagion to period of time off the host. The an effective therapy. Doramectin at cats. These cats do not need to be kennel facilities should be thor- 0.2 mg/kg SC or IM has also been treated. True “feline scabies” is caused oughly cleaned with high-pressure reported to be effective. Finally, by Notoedres cati, a contagious mange water, scrubbed with detergent, and two applications of selamectin or mite. In contrast to canine scabies mites, sprayed with an environmental par- fipronil at 30-day intervals may be N. cati is easily found in large numbers asiticidal agent. All dogs in contact effective. Selamectin is licensed on skin scrapings. Lesions occur on with these Great Danes should be for the treatment of scabies, and the head, feet, and perineum. This treated for scabies. Lime sulfur dips the manufacturer reported it to be infestation can cause large amounts once weekly for 6 weeks or amitraz effective in 70% of cases. Fipronil of crust; cats should be sedated, the dips every 2 weeks for 6 weeks are is not licensed for scabies treat- haircoat clipped, and the cats bathed effective topical therapies. Lime sul- ment but has been found to be to remove the contaminated crusts fur can be combined with ivermec- effective. It is important to remem- before treatment. Because cats are tin therapy. Ivermectin (200 μg/kg ber that no treatment is 100% effi- extremely sensitive to parasiticidal PO or SC) every 2 weeks for 6 weeks cacious in all patients. If scabies is agents, lime sulfur and ivermectin are is also an effective treatment. I use suspected and the patient does not the most commonly used treatments. a test dose of 100 μg/kg PO in all respond, retreatment with a differ- Affected cats, and all animals in con- dogs. If there are no adverse effects ent therapy should be performed tact with them, should be treated for consistent with ivermectin sensitiv- before scabies is ruled out. at least 6 weeks. Letters Call for Papers CONTINUED FROM PAGE 113 Toxicology. Philadelphia: Williams and Editor’s note: Thank you to the attentive readers who Wilkins; 1996:317-328. pointed out the difference Are you involved in research? 2. Gaynor AR, Dhupa N. Acute ethyl- between these articles and to ene glycol intoxication. Part II. Compend Contin Educ Pract Vet 1999;21(12):1124- the authors for their clarifica- Veterinary Therapeutics: Research in Applied 1133. tion. As in many aspects of Veterinary Medicine® is a quarterly journal dedicated 3. Dorman DC, Dye JA. Chemical tox- icities. In: Ettinger SJ, Feldman EC, eds. veterinary medicine, differ- to rapid publication. Textbook of Veterinary Internal Medicine. ent recommendations exist We invite the submission of clinical and laboratory 6th ed. St. Louis: Elsevier Saunders; based on clinical experience research manuscripts in small animal, large animal, 2005:257-258. 4. Richardson JA, Welch SL, Gwaltney- and patient presentation ver- and comparative medicine, including pathophysiology, Brant SM, et al. Metaldehyde toxicoses diagnosis, treatment, and prognosis. Prospective, sus laboratory chemistry, and in dogs. Compend Contin Educ Pract Vet retrospective, and corroborative studies are all 2003;25(5):376-380. different references reflect welcome. Submitted articles are scheduled to be 5. Mull RL. Metaldehyde poisoning. In: these variations. Awareness published 90 to 120 days after acceptance. Kirk RW, ed. Current Veterinary Therapy: of both laboratory and clini- Small Animal Practice VIII. London: WB Contact Cheryl Hobbs, 800-426-9119, ext 52408, Saunders; 1983:106-107. cal data is useful when deter- or email chobbs@vetlearn.com. 6. Tilley LP, Smith FWK Jr. The 5-Min- mining the most appropriate ute Veterinary Consult: Canine and Feline. treatment for an individual It’s not just therapeutics! 2nd ed. Philadelphia: Lippincott Williams & Wilkins;2000:958-959. patient. 114 Compendium: Continuing Education for Veterinarians® | March 2009 | CompendiumVet.com
- 21. C A S E i n B R I E F Probiotic Therapy Improves Chronic Feline Diarrhea Christy Evans Cutting, DVM Companion Animal Clinic Roseburg, Oregon Patient: Calliope, an 11-year-old domestic short-haired cat History: In January 2004, Calliope presented with constipation. We administered two enemas and prescribed 1 mL lactulose once every 12 to 24 hours. She did reason- ably well on lactulose for approximately 1 year, but the constipation returned. At this point, we increased the dose of lactulose to 1 mL every 8 hours, which worked until January 2006. This time, the constipation didn’t respond to enemas, so we sedated Calliope for ©Jeannine Cook manual removal of the impacted feces. Unfortunately, she didn’t tolerate sedation well. She became hypothermic and almost comatose; intensive care, including intravenous fluids with corticosteroids, was needed to help pull her through. She slowly improved over the next 3 days and began eating on the fourth day. She was sent home but returned the next day with diarrhea and vomiting. I referred Calliope her owner to the nearest specialist for more involved diagnostics and treatment. Luck- ily they obliged—Calliope was diagnosed with an abnormal colon that required a partial colectomy 2 days later. Veterinarian’s Comments Calliope has had no more problems with constipation, but she developed diarrhea I have been recommending Purina Veteri- for 6 months following surgery. nary Diets ® FortiFlora ® as a nutritional supplement for more than 2 years. I like Therapy Plan: After her surgery, I expected Calliope to have some loose stools, but FortiFlora for several reasons: It’s conven- when she presented with persistent diarrhea, I felt that her digestive system needed a ient to dispense and administer, it’s easy little help to restore its normal microflora balance. I recommended that we try Purina on the GI tract, cats love the taste, and it Veterinary Diets® FortiFlora® Feline Nutritional Supplement. I started sprinkling FortiFlora on her food each day. FortiFlora was definitely what she needed. Within the first week, works! Calliope’s owner really feels that she started eating more and her diarrhea resolved. FortiFlora made the difference for her cat. Eating has always been a challenge for Calliope; she’s very particular and will be- I commonly use the nutritional supple- come anorectic if she doesn’t like a particular food. She’s small to begin with (6 lb), ment in dogs and cats that develop mild so we’re constantly watchful for any weight loss. Because Calliope’s digestive system diarrhea when receiving antibiotics. It’s was so delicate after surgery, maintaining her appetite was a priority for us and her nice to have something to offer owners owner. In addition, Calliope had lost a significant when they call with this problem, without amount of weight, so we offered her a variety of having to change antibiotics or bring the commercial foods to encourage her to eat. pet back in for a recheck. I also com- monly use FortiFlora for pets with stress Outcome: Calliope really didn’t seem “better” until diarrhea—It seems to work very well for we started FortiFlora. Until recently, her owner was these cases. giving her the nutritional supplement daily because if I recommend that my veterinary col- she missed one dose, the diarrhea would return. Af- leagues try FortiFlora. It’s easy to admin- ter 2 years, her owner was able to discontinue ister; you just sprinkle the nutritional sup- FortiFlora, and Calliope is now eating well and doing plement on the pet’s food. It works fast great without any gastrointestinal problems! and is so simple and effective! This information has not been peer reviewed and does not necessarily reflect the opinions Sponsored by of, nor constitute or imply endorsement or recommendation by, the Publisher or Editorial Board. The Publisher is not responsible for any data, opinions, or statements provided herein.
- 22. Understanding Behavior Feline Hyperesthesia Syndrome* About This Column ❯❯ John Ciribassi, DVM, DACVB Behavior problems are a signifi- Chicagoland Veterinary Behavior Consultants Carol Stream, Illinois cant cause of death (euthanasia) in companion animals. While most veterinary practices are necessarily geared toward the medical aspect F eline hyperesthesia syndrome (FHS) is known by several names, including rolling skin disease, neurodermatitis, neuritis, psychomotor epilepsy, and pru- ritic dermatitis of Siamese.1,2 As evidenced by these names and by the use of of care, there are many opportuni- the term syndrome, FHS is not characterized as having a single etiology. In fact, ties to bring behavior awareness it is often a diagnosis of exclusion. The differential diagnosis for FHS includes into the clinic for the benefit of diseases related to the fields of dermatology, neurology, and behavior. Only after the pet, the owner, and ourselves. conditions relating to skin and the nervous system have been ruled out can this This column acknowledges the condition be labeled a behavior disorder. importance of behavior as part of veterinary medicine and speaks Signalment FHS can occur in cats of any age, but it is commonly seen in cats aged 1 to 5 practically about using it effectively years. Males and females are equally affected. While all breeds can be affected, in daily practice. Siamese, Burmese, Persian, and Abyssinian cats are more commonly afflicted.3 Clinical Signs As indicated by the name rolling skin disease, affected cats often show rippling or rolling skin along the lum- bar spine. Palpation of the lumbar musculature may elicit signs of pain. Mydriasis is common during bouts of FHS. Affected cats commonly stare at their tail, then attack QuickNotes the tail and/or flanks. Biting of the tail base, forelegs, and FHS can occur in cats paws is common. These cats of any age, but it is often run wildly around the commonly seen in home, vocalizing at the same cats aged 1 to 5 years. time. Normally calm cats may display aggression toward people or other cats in the household, while aggressive cats may display increased affection. The behavior may be induced by pet- ting or stroking the cat’s fur and most commonly occurs in the morning ©2009 Kelpfish/Shutterstock.com or later in the evening.2 Diagnosis The differential diagnosis for FHS *Adapted with permission from John Ciribassi, DVM, and the Veterinary can be categorized by the type of Information Network (VIN). clinical signs displayed: 116 CompendiumVet.com | March 2009
- 23. Raising the level of care “AAHA is continually looking for ways to help member practices run better. AAHA endorses Vetstreet because it offers clinics an important client outreach tool. The Vetstreet Pet Portal® service allows us to better connect with and educate our clients, increase compliance and, most importantly, raise the level of health care for our patients. ” Anna Worth, VMD 2008-2009 AAHA President West Mountain Veterinary Hospital Bennington, VT Recommended by Easy to set up and easy to use, Vetstreet® is a powerful practice communication and management tool that keeps you in touch with your clients via Pet Portals. To discover how Vetstreet can help you increase client satisfaction, build compliance, and enhance your bottom line, visit Vetstreet.com, call toll-free 888-799-8387 or email info@vetstreet.com. , Vetstreet and Pet Portal are registered trademarks of VetInsite.com, Inc.
- 24. Understanding Behavior Dermatologic: Flea allergy dermatitis, food unrelated, behavior such as grooming. If this allergy, atopy, infectious dermatitis conflicting situation persists over a prolonged Neurologic: Epilepsy, brain tumors, spinal period, the cat may engage in the displace- disease (disk disease, neoplasia, infectious ment behavior even when the competing myelitis) motivations are no longer present. This is Musculoskeletal: Myositis, myopathy then defined as a compulsive behavior. Behavioral: Compulsive disorder, displace- The environmental factors that trigger ment behavior compulsive behaviors exert their influence by stimulating the hypothalamus and the limbic A minimum database to aid in diagnos- system, which in turn activate motor activity ing FHS should include a physical exami- through the basal ganglia. Three types of neu- nation, neurologic examination, complete rotransmitters are reported to be involved: blood count, serum chemistry profile (espe- cially hepatic and renal function), urinalysis, Dopamine. Increased dopamine levels can and spinal radiography. Depending on these result in increased frequency of compulsive results, further diagnostics might include skin behaviors. scraping, fungal culture, skin and/or muscle Opiates. One theory is that when animals biopsy, spinal or cranial imaging (computed engage in compulsive behaviors, levels of QuickNotes tomography or magnetic resonance imaging), opiates in the brain are elevated, and the electromyography, food trials, and pharma- pleasurable effects that opiates promote Successful therapy is ceutical trials (flea control, corticosteroids, reinforce the behaviors. Another theory is based on reasonable antiseizure medication). The decision of that opiates initiate stereotypic behavior. owner expectations which tests to run and in what order depends This theory is based on the observation that and the ability to on the patience and financial situation of the administration of opioids enhances the dis- monitor the degree owner and the severity of the clinical signs. play of amphetamine-induced stereotypic of improvement. While running the gamut of tests is ideal, it behaviors, but these behaviors are blocked may be more practical to use pharmaceuti- when narcotic antagonists (such as nalox- cal trials once the baseline database has been one) are administered.4 collected. I typically suggest a trial of flea Serotonin. Serotonin is produced in the dor- control medication and, if there is no change, sal raphe nucleus, and its influence on the treatment with corticosteroids at antiinflam- basal ganglia and frontal cortex affects behav- matory doses. If the patient does not respond iors such as compulsive disorders. Higher to steroid treatment, treatment with an anti- levels of serotonin reduce the incidence of seizure medication is indicated. Phenobarbital compulsive disorders, which is the rationale is my initial antiseizure drug of choice; some for the use of selective serotonin reuptake practitioners also use gabapentin. inhibitors (SSRIs) to treat these disorders. If none of the above approaches results in an improvement in the cat’s condition, then a Treatment presumed diagnosis of behavioral FHS can be Successful therapy is based on reasonable made. owner expectations and the ability to moni- tor the degree of improvement. This can be Pathophysiology accomplished by recording the frequency and FHS is commonly considered to be a com- severity of signs of FHS during the treatment pulsive disorder resulting in self-injurious period. behavior. One proposed trigger of FHS is displacement behavior. Displacement behav- Behavior Modification ©2009 Dr. Margorius/Shutterstock.com ior occurs as an alternative to two other con- As with many behavior problems in compan- flicting behaviors. An example might be a cat ion animals, the treatment of FHS combines that wants to eat but is being prevented from behavior modification protocols and the use doing so by an aggressive cat in the house- of psychoactive pharmaceuticals. Behaviorally, hold. The competing motivations, hunger and the goal is to create a stable and consistent fear, cause the affected cat to want to simulta- environment for the cat. This can be accom- neously perform the conflicting behaviors of plished in the following ways: eating and escaping. As a consequence, the Institute a regular feeding schedule to pro- cat might perform a species-appropriate, but vide a more predictable source of food. 118 Compendium: Continuing Education for Veterinarians® | March 2009 | CompendiumVet.com
- 25. So you think you know everything about SevoFlo®(sevoflurane)… ...a few dollars more* gives you all that SevoFlo has to offer. • SevoFlo is only a few dollars more per procedure and with your normal markups can increase your potential profits. • SevoFlo can provide the opportunity to differentiate your talents and practice from others. • SevoFlo doesn’t irritate airways1 and is less of a respiratory depressant than isoflurane2. • SevoFlo has low blood:gas solubility and a greater range of vaporizer settings to give veterinarians rapid, precise control over the depth of anesthesia. For only a few dollars more* you get all of the benefits of SevoFlo. Speak to your sales representative, contact Abbott Animal Health at 888-299-7416 or visit us at www.abbottanimalhealth.com today. Important Information: How Supplied: SevoFlo is packaged in amber colored bottles containing 250 mL sevoflurane. Indications: SevoFlo is indicated for induction and maintenance of general anesthesia in dogs. Warnings, Precautions, and Contraindications: Like other inhalation anesthetics, sevoflurane is a profound respiratory depressant. Respiration must be monitored closely in the dog and supported when necessary with supplemental oxygen and/or assisted ventilation. Due to sevoflurane’s low solubility in blood, increasing concentration may result in rapid hemodynamic changes compared to other volatile anesthetics. SevoFlo is contraindicated in dogs with a known sensitivity to sevoflurane or other halogenated agents. Adverse Reactions: The most frequently reported adverse reactions during maintenance anesthesia were hypotension, followed by tachypnea, muscle tenseness, excitation, apnea, muscle fasciculations and emesis. See package insert for full prescribing information. 1 T Mutoh, A Kanamura, H Suzuki, H Tsubone, R Nishimura, N Sasaki. AJVR 2001:62:311-319 2 DS Galloway JCH Ko, HF Reaugh, RE Mandsager, ME Payton, T Inoue, E Portillo. JAVMA (2004) Vol 255, No 5, 700-704 * Per procedure. SEVO-210 February 2009 ©2009 Abbott Laboratories See Page 120 for Product Information Summary
- 26. PRECAUTIONS: Halogenated volatile anesthetics can react with desiccated decreased at hourly intervals, from 500 mL/min (36 and 18 ppm Compound A) to 250 SevoFlo® 5458 carbon dioxide (CO2) absorbents to produce carbon monoxide (CO) that may mL/min (43 and 31 ppm) to 50 mL/min (61 and 48 ppm).8 (sevoflurane) result in elevated carboxyhemoglobin levels in some patients. To prevent this Fluoride ion metabolite: Sevoflurane is metabolized to hexafluoroisopropanol (HFIP) reaction, sevoflurane should not be passed through desiccated soda lime or with release of inorganic fluoride and CO2. Fluoride ion concentrations are influenced by Inhalation Anesthetic For Use in Dogs barium hydroxide lime. the duration of anesthesia and the concentration of sevoflurane. Once formed, HFIP is Caution: Federal law restricts this drug to use by or on the order of a Replacement of Desiccated CO2 Absorbents: When a clinician suspects rapidly conjugated with glucuronic acid and eliminated as a urinary metabolite. No other licensed veterinarian. that the CO2 absorbent may be desiccated, it should be replaced before metabolic pathways for sevoflurane have been identified. In humans, the fluoride ion DESCRIPTION: SevoFlo (sevoflurane), a volatile liquid, is a halogenated administration of sevoflurane. The exothermic reaction that occurs with half-life was prolonged in patients with renal impairment, but human clinical trials general inhalation anesthetic drug. Its chemical name is fluoromethyl 2,2,2- sevoflurane and CO2 absorbents is increased when the CO2 absorbent contained no reports of toxicity associated with elevated fluoride ion levels. In a study in trifluoro-l- (trifluoromethyl) ethyl ether, and its structural formula is: becomes desiccated, such as after an extended period of dry gas flow through which 4 dogs were exposed to 4% sevoflurane for 3 hours, maximum serum fluoride the CO2 absorbent canisters. Extremely rare cases of spontaneous fire in the concentrations of 17.0-27.0 mcmole/L were observed after 3 hours of anesthesia. respiratory circuit of the anesthesia machine have been reported during Serum fluoride fell quickly after anesthesia ended, and had returned to baseline by 24 sevoflurane use in conjunction with the use of a desiccated CO2 absorbent, hours post-anesthesia. In a safety study, eight healthy dogs were exposed to specifically those containing potassium hydroxide (e.g. BARALYME). sevoflurane for 3 hours/day, 5 days/week for 2 weeks (total 30 hours exposure) at a Potassium hydroxide containing CO2 absorbents are not recommended for use flow rate of 500 mL/min in a semi-closed, rebreathing system with soda lime. Renal Sevoflurane Physical Constants are: with sevoflurane. An unusually delayed rise in the inspired gas concentration toxicity was not observed in the study evaluation of clinical signs, hematology, serum Molecular weight 200.05 (decreased delivery) of sevoflurane compared with the vaporizer setting may chemistry, urinalysis, or gross or microscopic pathology. Boiling point at 760 mm Hg 58.6°C indicate excessive heating of the CO2 absorbent canister and chemical DRUG INTERACTIONS: In the clinical trial, sevoflurane was used safely in dogs that Specific gravity at 20°C 1.520-1.525 g/mL breakdown of sevoflurane. The color indicator of most CO2 absorbent may not received frequently used veterinary products including steroids and heartworm and flea Vapor pressure in mm Hg at 20°C 157 change upon desiccation. Therefore, the lack of significant color change preventative products. at 25°C 197 should not be taken as an assurance of adequate hydration. CO2 absorbents Intravenous Anesthetics: Sevoflurane administration is compatible with barbiturates, at 36°C 317 should be replaced routinely regardless of the state of the color indicator. propofol and other commonly used intravenous anesthetics. Benzodiazepines and Distribution Partition Coefficients at 37°C: Opioids: Benzodiazepines and opioids would be expected to decrease the MAC of The use of some anesthetic regimens that include sevoflurane may result in Blood/Gas 0.63-0.69 sevoflurane in the same manner as other inhalational anesthetics. Sevoflurane is bradycardia that is reversible with anticholinergics. Studies using sevoflurane Water/Gas 0.36 compatible with benzodiazepines and opioids as commonly used in surgical practice. anesthetic regimens that included atropine or glycopyrrolate as premedicants Olive Oil/Gas 47-54 Phenothiazines and Alpha2-Agonists: Sevoflurane is compatible with phenothiazines showed these anticholinergics to be compatible with sevoflurane in dogs. Brain/Gas 1.15 and alpha2- agonists as commonly used in surgical practice. During the induction and maintenance of anesthesia, increasing the Mean Component/Gas Partition Coefficients at 25°C for Polymers Used In a laboratory study, the use of the acepromazine/oxymorphone/ thiopental/sevoflurane concentration of sevoflurane produces dose dependent decreases in blood Commonly in Medical Applications: anesthetic regimen resulted in prolonged recoveries in eight (of 8) dogs compared to pressure and respiratory rate. Due to sevoflurane’s low solubility in blood, Conductive rubber 14.0 recoveries from sevoflurane alone. these changes may occur more rapidly than with other volatile anesthetics. Butyl rubber 7.7 CLINICAL EFFECTIVENESS: Excessive decreases in blood pressure or respiratory depression may be Polyvinyl chloride 17.4 The effectiveness of sevoflurane was investigated in a clinical study involving 196 dogs. related to depth of anesthesia and may be corrected by decreasing the Polyethylene 1.3 Thirty dogs were mask-induced with sevoflurane using anesthetic regimens that inspired concentration of sevoflurane. RESPIRATION MUST BE MONITORED included various premedicants. During the clinical study, one hundred sixty-six dogs CLOSELY IN THE DOG AND SUPPORTED WHEN NECESSARY WITH Sevoflurane is nonflammable and nonexplosive as defined by the requirements of received sevoflurane maintenance anesthesia as part of several anesthetic regimens SUPPLEMENTAL OXYGEN AND/OR ASSISTED VENTILATION. The low International Electrotechnical Commission 601-2-13. Sevoflurane is a clear, that used injectable induction agents and various premedicants. The duration of solubility of sevoflurane also facilitates rapid elimination by the lungs. colorless, stable liquid containing no additives or chemical stabilizers. anesthesia and the choice of anesthetic regimens were dependent upon the procedures The use of sevoflurane in humans increases both the intensity and duration of Sevoflurane is nonpungent. It is miscible with ethanol, ether, chloroform and that were performed. Duration of anesthesia ranged from 16 to 424 minutes among the neuromuscular blockade induced by nondepolarizing muscle relaxants. The petroleum benzene, and it is slightly soluble in water. Sevoflurane is stable when individual dogs. Sevoflurane vaporizer concentrations during the first 30 minutes of use of sevoflurane with nondepolarizing muscle relaxants has not been stored under normal room lighting condition according to instructions. maintenance anesthesia were similar among the various anesthetic regimens. The evaluated in dogs. INDICATIONS: SevoFlo is indicated for induction and maintenance of general quality of maintenance anesthesia was considered good or excellent in 169 out of 196 Compromised or debilitated dogs: Doses may need adjustment for geriatric or anesthesia in dogs. dogs. The table shows the average vaporizer concentrations and oxygen flow rates debilitated dogs. Because clinical experience in administering sevoflurane to DOSAGE AND ADMINISTRATION: Inspired Concentration: The delivered during the first 30 minutes for all sevoflurane maintenance anesthesia regimens: dogs with renal, hepatic and cardiovascular insufficiency is limited, its safety in concentration of SevoFlo should be known. Since the depth of anesthesia may these dogs has not been established. Average Average Average Average be altered easily and rapidly, only vaporizers producing predictable percentage Breeding dogs: The safety of sevoflurane in dogs used for breeding purposes, Vaporizer Vaporizer Oxygen Oxygen concentrations of sevoflurane should be used. Sevoflurane should be vaporized during pregnancy, or in lactating bitches, has not been evaluated. Concentrations Concentrations Flow Flow using a precision vaporizer specifically calibrated for sevoflurane. Sevoflurane Neonates: The safety of sevoflurane in young dogs (less than 12 weeks of among among Rates Rates contains no stabilizer. Nothing in the drug product alters calibration or operation age) has not been evaluated. Anesthetic Individual among among of these vaporizers. The administration of general anesthesia must be Regimens Dogs Anesthetic Individual HUMAN SAFETY: Not for human use. Keep out of reach of children. Regimens Dogs individualized based on the patient’s response. WHEN USING SEVOFLURANE, Operating rooms and animal recovery areas should be provided with 3.31 - 3.63% 1.6 - 5.1% 0.97 - 1.31 0.5 - 3.0 PATIENTS SHOULD BE CONTINUOUSLY MONITORED AND FACILITIES adequate ventilation to prevent the accumulation of anesthetic vapors. L/minute L/minute FOR MAINTENANCE OF PATENT AIRWAY, ARTIFICIAL VENTILATION, AND There is no specific work exposure limit established for sevoflurane. However, OXYGEN SUPPLEMENTATION MUST BE IMMEDIATELY AVAILABLE. the National Institute for Occupational Safety and Health has recommended an During the clinical trial, when a barbiturate was used for induction, the times to Replacement of Desiccated CO2 Absorbents: When a clinician suspects that 8 hour time-weighted average limit of 2 ppm for halogenated anesthetic agents extubation, sternal recumbency and standing recovery were longer for dogs that the CO2 absorbent may be desiccated, it should be replaced. An exothermic in general. Direct exposure to eyes may result in mild irritation. If eye exposure received anesthetic regimens containing two preanesthetics compared to regimens reaction occurs when sevoflurane is exposed to CO2 absorbents. This reaction is occurs, flush with plenty of water for 15 minutes. Seek medical attention if containing one preanesthetic. Recovery times were shorter when anesthetic regimens increased when the CO2 absorbent becomes desiccated (see PRECAUTIONS). irritation persists. Symptoms of human overexposure (inhalation) to used sevoflurane or propofol for induction. The quality of recovery was considered good Premedication: No specific premedication is either indicated or contraindicated sevoflurane vapors include respiratory depression, hypotension, bradycardia, or excellent in 184 out of 196 dogs. Anesthetic regimen drug dosages, physiological with sevoflurane. The necessity for and choice of premedication is left to the shivering, nausea and headache. If these symptoms occur, remove the responses, and the quality of induction, maintenance and recovery were comparable discretion of the veterinarian. Preanesthetic doses for premedicants may be individual from the source of exposure and seek medical attention. The between 10 sighthounds and other breeds evaluated in the study. During the clinical lower than the label directions for their use as a single medication.1 material safety data sheet (MSDS) contains more detailed occupational safety study there was no indication of prolonged recovery times in the sighthounds. Induction: For mask induction using sevoflurane alone, inspired concentrations information. For customer service, adverse effects reporting, and/or a HOW SUPPLIED: SevoFlo (sevoflurane) is packaged in amber colored bottles up to 7% sevoflurane with oxygen are employed to induce surgical anesthesia in copy of the MSDS, call (888) 299-7416. containing 250 mL sevoflurane, List 5458. the healthy dog. These concentrations can be expected to produce surgical CLINICAL PHARMACOLOGY: Sevoflurane is an inhalational anesthetic STORAGE CONDITIONS: Store at controlled room temperature 15°-30°C (59°-86°F). anesthesia in 3 to 14 minutes. Due to the rapid and dose dependent changes agent for induction and maintenance of general anesthesia. The Minimum REFERENCES: in anesthetic depth, care should be taken to prevent overdosing. Alveolar Concentration (MAC) of sevoflurane as determined in 18 dogs is 1. Plumb, D.C. ed., Veterinary Drug Handbook, Second Edition, University of Iowa Respiration must be monitored closely in the dog and supported when 2.36%.2 MAC is defined as that alveolar concentration at which 50% of healthy Press, Ames, IA: p. 424 (1995). necessary with supplemental oxygen and/or assisted ventilation. 2. Kazama, T. and Ikeda, K., Comparison of MAC and the rate of rise of alveolar patients fail to respond to noxious stimuli. Multiples of MAC are used as a Maintenance: SevoFlo may be used for maintenance anesthesia following mask guide for surgical levels of anesthesia, which are typically 1.3 to 1.5 times the concentration of sevoflurane with halothane and isoflurane in the dog. Anesthesiology. induction using sevoflurane or following injectable induction agents. The MAC value. Because of the low solubility of sevoflurane in blood (blood/gas 68: 435-437 (1988). concentration of vapor necessary to maintain anesthesia is much less than that partition coefficient at 37°C = 0.63-0.69), a minimal amount of sevoflurane is 3. Scheller, M.S., Nakakimura, K., Fleischer, J.E. and Zornow, M.H., Cerebral effects of required to induce it. Surgical levels of anesthesia in the healthy dog may be required to be dissolved in the blood before the alveolar partial pressure is in sevoflurane in the dog: Comparison with isoflurane and enflurane. Brit. J. Anesthesia maintained with inhaled concentrations of 3.7-4.0% sevoflurane in oxygen in the equilibrium with the arterial partial pressure. During sevoflurane induction, 65: 388-392 (1990). absence of premedication and 3.3-3.6% in the presence of premedication. The there is a rapid increase in alveolar concentration toward the inspired 4. Frink, E.J., Morgan, S.E., Coetzee, A., Conzen, P.F. and Brown, B.R., Effects of use of injectable induction agents without premedication has little effect on the concentration. Sevoflurane produces only modest increases in cerebral blood sevoflurane, halothane, enflurane and isoflurane on hepatic blood flow and oxygenation concentrations of sevoflurane required for maintenance. Anesthetic regimens that flow and metabolic rate, and has little or no ability to potentiate seizures.3 in chronically instrumented greyhound dogs. Anesthesiology 76: 85-90 (1992). include opioid, alpha2-agonist, benzodiazepine or phenothiazine premedication Sevoflurane has a variable effect on heart rate, producing increases or 5. Kazama, T. and Ikeda, K., The comparative cardiovascular effects of sevoflurane will allow the use of lower sevoflurane maintenance concentrations. decreases depending on experimental conditions.4,5 Sevoflurane produces with halothane and isoflurane. J. Anesthesiology 2: 63-8 (1988). CONTRAINDICATIONS: SevoFlo is contraindicated in dogs with a known dose-dependent decreases in mean arterial pressure, cardiac output and 6. Bernard, J. M., Wouters, P.F., Doursout, M.F., Florence, B., Chelly, J.E. and Merin, sensitivity to sevoflurane or other halogenated agents. myocardial contraction.6 Among inhalation anesthetics, sevoflurane has low R.G., Effects of sevoflurane on cardiac and coronary dynamics in chronically WARNINGS: Sevoflurane is a profound respiratory depressant. DUE TO THE arrhythmogenic potential.7 Sevoflurane is chemically stable. No discernible instrumented dogs. Anesthesiology 72: 659-662 (1990). RAPID AND DOSE DEPENDENT CHANGES IN ANESTHETIC DEPTH, degradation occurs in the presence of strong acids or heat. Sevoflurane reacts 7. Hayaski, Y., Sumikawa, K., Tashiro, C., Yamatodani, A. and Yoshiya, I., RESPIRATION MUST BE MONITORED CLOSELY IN THE DOG AND through direct contact with CO2 absorbents (soda lime and barium hydroxide Arrhythmogenic threshold of epinephrine during sevoflurane, enflurane and isoflurane SUPPORTED WHEN NECESSARY WITH SUPPLEMENTAL OXYGEN lime) producing pentafluoroisopropenyl fluoromethyl ether (PIFE, C4H2F6O), anesthesia in dogs. Anesthesiology 69: 145-147 (1988). AND/OR ASSISTED VENTILATION. also known as Compound A, and trace amounts of pentafluoromethoxy 8. Muir, W.W. and Gadawski, J., Cardiorespiratory effects of low-flow and closed circuit In cases of severe cardiopulmonary depression, discontinue drug administration, isopropyl fluoromethyl ether (PMFE, C5H6F6O), also known as Compound B. inhalation anesthesia, using sevoflurane delivered with an in-circuit vaporizer and ensure the existence of a patent airway and initiate assisted or controlled Compound A: The production of degradants in the anesthesia circuit results concentrations of compound A. Amer. J. Vet. Res. 59 (5): 603-608 (1998). ventilation with pure oxygen. Cardiovascular depression should be treated with from the extraction of the acidic proton in the presence of a strong base plasma expanders, pressor agents, antiarrhythmic agents or other techniques as (potassium hydroxide and/or NaOH) forming an alkene (Compound A) from NADA 141-103, Approved by FDA appropriate for the observed abnormality. Due to sevoflurane’s low solubility in SevoFlo® is a registered trademark of Abbott Laboratories. sevoflurane. blood, increasing the concentration may result in rapid changes in anesthetic Compound A is produced when sevoflurane interacts with soda lime or barium Manufactured by Abbott Laboratories, North Chicago, IL depth and hemodynamic changes (dose dependent decreases in respiratory rate hydroxide lime. Reaction with barium hydroxide lime results in a greater 60064, USA and blood pressure) compared to other volatile anesthetics. Excessive decreases production of Compound A than does reaction with soda lime. Its concentration Product of Japan in blood pressure or respiratory depression may be corrected by decreasing or in a circle absorber system increases with increasing sevoflurane discontinuing the inspired concentration of sevoflurane. Under license from concentrations and with decreasing fresh gas flow rates. Sevoflurane Maruishi Pharmaceutical Co., LTD Potassium hydroxide containing CO2 absorbents (e.g. BARALYME®) are not degradation in soda lime has been shown to increase with temperature. Since 2-3-5, Fushimi-Machi, Chuo-Ku, recommended for use with sevoflurane. the reaction of carbon dioxide with absorbents is exothermic, this temperature Osaka, Japan ADVERSE REACTIONS: The most frequently reported adverse reactions during increase will be determined by the quantities of CO2 absorbed, which in turn maintenance anesthesia were hypotension, followed by tachypnea, muscle For customer service call (888) 299-7416. will depend on fresh gas flow in the anesthetic circle system, metabolic status tenseness, excitation, apnea, muscle fasciculations and emesis. of the patient and ventilation. Although Compound A is a dose-dependent Infrequent adverse reactions include paddling, retching, salivation, cyanosis, ©Abbott 8/2006 nephrotoxin in rats, the mechanism of this renal toxicity is unknown. Two Taken from Commodity Number 03-5474/R6, SevoFlo, sevoflurane, package insert, January 11, 2007 premature ventricular contractions and excessive cardiopulmonary depression. spontaneously breathing dogs under sevoflurane anesthesia showed Transient elevations in liver function tests and white blood cell count may occur increases in concentrations of Compound A as the oxygen flow rate was with sevoflurane, as with the use of other halogenated anesthetic agents. SEVO-152 January 2007 page 1 of 1 ©2007 Abbott Laboratories
- 27. Understanding Maintain consistency in interactions with the administration of the medication. If the patient Behavior cat. When managing dogs with a compulsive is receiving combination therapy (an SSRI or disorder, one common recommendation is TCA with a benzodiazepine), the medications for the owners to use a command–response– should be weaned one at a time to determine reward technique for all interactions. For which drug is responsible if signs return as the example, the owner asks the dog to sit and, dose is reduced. after the dog obeys, gives it a treat. The same technique can be used with cats. Selective Serotonin Reuptake Inhibitors Provide regular play sessions using target- The following dosages are recommended for type toys (e.g., feather toys). cats with FHS6: Anticipate situations that trigger the behavior. When the behavior is likely to occur, redirect Fluoxetine: 0.5 to 2.0 mg/kg PO q24h the cat’s activity to more appropriate behav- Paroxetine: 0.5 to 1.0 mg/kg PO q12–24h iors, such as training exercises or play.3,5 The adverse effects of SSRIs include seda- FHS behaviors should not be punished tion, anorexia, irritability, vomiting, and diar- because punishment will increase the cat’s con- rhea. In addition, SSRIs inhibit the function of QuickNotes flict and stress, resulting in a likely increase in the liver cytochrome P450 enzymes CYP2C9, the problem behaviors. CYP2D6, CYP2C19, and CYP3A4. As a conse- FHS behaviors should quence, care should be taken when prescrib- not be punished Pharmaceutical Intervention ing concurrent medications that rely on these because punishment There are no US Food and Drug Administration– enzymes for their metabolism (e.g., pheno- will increase the cat’s approved medications for treating FHS or barbital, carbamazepine, benzodiazepines, conflict and stress, any other compulsive disorder in pets. Con- TCAs). SSRIs should not be used in combina- resulting in a likely sequently, owners should be informed of the tion with each other or with other drugs that increase in the potential risks as well as the possible benefits increase serotonin levels, such as monoam- problem behaviors. of the use of behavior medications. It is always ine oxidase inhibitors (e.g., selegiline), other wise to conduct appropriate laboratory testing SSRIs (e.g., paroxetine, sertraline), or TCAs to confirm normal hepatic and renal function (e.g., amitriptyline, imipramine, doxepin). before prescribing these medications, which are metabolized and eliminated by the liver Tricyclic Antidepressants and kidneys. It is also helpful to repeat test- Of the TCAs, clomipramine (0.5 to 1.0 mg/kg ing approximately 4 weeks after instituting PO q24h)7 can be used to treat FHS. Adverse therapy to evaluate the medication’s effect on effects associated with this drug include organ (particularly hepatic) function. sedation, anticholinergic effects, potentiation The three main classes of medications used of arrhythmias in predisposed patients, and to treat FHS are SSRIs, tricyclic antidepressants lowering of the seizure threshold in patients (TCAs), and benzodiazepines. When using any with seizure disorders. of these medications in cats, it is best to begin at the lower end of the dose range, then titrate Benzodiazepines upward as needed to achieve the desired The following dosages 8 are recom- response. This approach minimizes the poten- mended for cats with FHS. These tial for serious side effects such as prolonged benzodiazepines are recommended anorexia or excessive sedation. in cats because they do not have active Once the frequency of the behavior metabolites. Diazepam has been impli- reaches an acceptable level, treatment should cated in cases of hepatic necrosis in cats. ©2009 Vasiliy Koval/Shutterstock.com be maintained for 4 to 6 months. The dose Lorazepam: 0.125 to 0.50 mg PO q8–24h can then be gradually reduced (25% reduction Oxazepam: 0.20 to 0.50 mg/kg PO q12–24h every 1 to 2 weeks) until the patient has been weaned off the drug. If the behavior recurs The potential adverse effects of these drugs or increases in frequency during the weaning include sedation, ataxia, and temperament process, the previously effective dose should changes. Combination therapy with an SSRI or be reinstituted. Another reduction may be a TCA is acceptable with either of these drugs attempted after another 4 to 6 months of ther- if no agent alone provides sufficient response. apy; however, some patients require lifelong CONTINUES ON PAGE 132 CompendiumVet.com | March 2009 | Compendium: Continuing Education for Veterinarians® 121
- 28. 3 CE CREDITS CE Article 1 Vomiting ❯❯ Héctor J. Encarnación, DVM Abstract: Vomiting is the forceful expulsion of stomach contents through the mouth, caused by Gulf Coast Veterinary humoral stimulation of the chemoreceptor trigger zone (CRTZ) or neural stimulation of the emetic Specialists Houston, Texas center. The CRTZ is activated and controlled by neurotransmitter manipulation at the receptor level. Clinical signs preceding vomiting may include ptyalism, tachycardia, depression, hiding, ❯❯ Joshua Parra, DVM and yawning. Gastritis, gastrointestinal ulceration, pancreatitis, motion sickness, uremia, chemo- Florida Veterinary Referral therapy, and drug administration are common initiating causes of vomiting. This article reviews Center and 24-Hour the anatomic and physiologic aspects of the vomiting reflex and its neurotransmitters, associated Emergency and Critical Care Hospital receptors, and rational management. Estero, Florida E mesis, or vomiting, is one of the components. The emetic center (1)2,6–12 ❯❯ Erick Mears, DVM, DACVIM most common reasons dogs and receives input from (2) the gastrointestinal Valerie Sadler, DVM, DACVR cats present for medical evalua- tract (afferent neurons),2,7–11,13 (3) the higher Florida Veterinary Specialists tion.1 Vomiting is often associated with centers of the brain,2,7–9,13 (4) the vestibu- and Cancer Treatment Center mild, self-limiting diseases that resolve lar apparatus,2,6–13 and (5) the CRTZ.2,6–13 Tampa, Florida with minimal diagnostic tests and therapy. Finally, to coordinate the vomiting reflex, However, it can be related to debilitating the vomiting center sends signals through conditions that have life-threatening con- (6) the efferent motor neurons.7,8,10 The sequences. The history obtained from the vagal and sympathetic afferent neurons client should be as detailed as possible originate from the gastrointestinal tract, because historical details are often helpful particularly the duodenum, as well as in selecting the appropriate treatment and other areas, including the urinary and diagnostic plan. Questions to ask during reproductive system, liver, pancreas, peri- At a Glance the history should include onset of vomit- toneum, and cardiac vessels. Stimulation ing, duration of clinical signs, type and of these neurons initiates the impulse that The Vomiting Reflex Page 122 frequency of vomiting, relation to food travels directly to the emetic center. The ingestion, characteristics of the vomited higher centers of the brain, including the Antiemetics contents, diet history, and environment. cerebral cortex and the limbic system, can Page 124 Questions about known medical condi- trigger emesis through three mechanisms: Vomiting Reflex tions and current therapies are also per- direct stimulation of the vomiting center by Components, Receptors, tinent because these factors may play an inflammatory diseases, hydrocephalus, or and Controlling active role in the inciting cause. neoplasia; psychogenic stimulation caused Neurotransmitters by fear, stress, excitement, or pain; and trau- and Medications The Vomiting Reflex matic stimulation related to head injuries Page 125 Pathophysiology and increased intracranial pressure.7,9 Most Common Antiemetics Vomiting is a reflex act that is mediated The CRTZ is a bilateral set of centers in Used in Small Animal neurologically by the activation of the the brainstem, located on the floor of the Medicine bilateral nucleus tractus solitarii, or emetic fourth ventricle. It possesses free nerve end- Page 127 center, situated in the parvicellular reticu- ings that maintain direct contact with the Treatment of Common lar formation in the lateral region of the cerebrospinal fluid via ependymal pores or Vomiting Conditions medulla oblongata. This is the area that the sheath surrounding fenestrated capil- Page 128 initiates, controls, regulates, and orga- laries.9,14 These free nerve endings are acti- Most Common Causes of nizes the vomiting reflex.2–5 vated by the vestibular system or through Vomiting in Dogs and Cats Vomiting can be triggered by both the humoral pathway by conditions affect- Page 129 neural and humoral pathways.2 The neu- ing the blood or cerebrospinal fluid (e.g., ral pathway comprises six fundamental drug administration, infection, osmolar 122 Compendium: Continuing Education for Veterinarians® | March 2009 | CompendiumVet.com
- 29. You can’t always be sure what a patient has gotten into, and you know tapeworms. It’s the proven intestinal parasite treatment veterinarians he’ll never talk. If you don’t know what he got into, you can’t know what have relied on for years. intestinal parasites got into him. Treat him with Drontal® Plus. If he did eat something he shouldn’t have, you know he’ll never confess. Drontal® Plus effectively removes most of the common intestinal parasites Don’t take chances. Choose Drontal® Plus. that can infect dogs, including hookworms, roundworms, whipworms and Federal (U.S.A.) law restricts this drug to use by or on the order of a licensed veterinarian. Do not use in pregnant animals. © 2009 Bayer HealthCare LLC, Animal Health Division, Shawnee Mission, Kansas 66201. Bayer, the Bayer Cross and Drontal are registered trademarks of Bayer. D08676n See Page 124 for Product Information Summary
- 30. FREE CE Vomiting and acid–base disorders, electrolyte negative intrathoracic pressure and derangements, metabolic diseases).15 positive intraabdominal pressure, Finally, to initiate the vomiting facilitating the movement of gastric reflex, efferent motor signals must contents into the esophagus. Before be transmitted to the upper gastro- expulsion, the respiratory center is intestinal tract through the sensory inhibited and the nasopharynx and aspect of cranial nerves V, VII, IX, glottis close to prevent pulmonary X, and XII and to the diaphragm aspiration and nasal regurgitation of and abdominal muscles via the spi- the gastric contents. The third and nal nerves.8 last phase of vomiting is the expul- sion of stomach contents through the Anatomy mouth. The act of vomiting is composed of three phases: nausea, retching, and Antiemetics expulsion of proximal duodenal Antiemetics are drugs that block the and gastric contents.6,7,16 Nausea is vomiting reflex9,23,24 by impeding the conscious recognition of sub- neurotransmission at central (CRTZ, conscious excitation in an area of emetic center) and peripheral (gas- the medulla that is closely associ- trointestinal epithelium) recep- ated with the vomiting center. This tor sites. These drugs are classified excitation is caused by irritative based on the type of receptor they impulses coming from the gastroin- block (TABLE 1). However, antiemet- testinal tract, lower brain, or cerebral ics have the potential to prolong gas- cortex.15,17–19 Ptyalism, tachycardia, trointestinal infections, predispose nervousness, hiding or seeking patients to such infections, and pre- attention, shivering, and yawning vent toxin elimination by decreas- are all characteristic signs of nau- ing gastrointestinal motility. The use sea triggered by general activation of most of these drugs in animals of the sympathetic and parasympa- is off-label, and some dosages are thetic branches of the autonomic extrapolated from the human medi- nervous system. Hypersalivation cal literature (TABLE 2). stimulates swallowing, which stimu- lates relaxation of the gastroesopha- Phenothiazines geal sphincter. The bicarbonate-rich Phenothiazines are broad-spec- saliva secreted by the salivary glands trum antiemetics that have antido- in the mouth lubricates the esopha- paminergic and antihistaminergic gus and helps neutralize the stom- properties at low doses in the ach’s acidic environment before CRTZ and anticholinergic effects at vomiting.8,13 Before retching, abo- higher doses at other central sites, ral gastric and esophageal motility including the emetic center.9 These diminishes and the lower esopha- drugs also block norepinephrine geal and pyloric sphincters relax. at peripheral α-adrenergic recep- Retching is the second phase of tors. Drugs in this group include vomiting and begins with the onset chlorpromazine, prochlor perazine, of a retrograde giant contraction.20,21 and acetylpromazine. Common This contraction is a single-phase, ret- adverse effects in small animals, rograde, peristaltic motion that emp- especially dogs, include ataxia, ties the proximal duodenal contents hypotension, and excessive seda- into the stomach.20–22 It is followed by tion. Generalized central nervous deep inspiratory movements, force- system (CNS) stimulation, aggres- ful contractions of the abdominal siveness, violent behavior, extrapy- muscles and diaphragm, and closure ramidal effects, and seizures are of the glottis. These actions produce rare. Fluid therapy is indicated in 124 Compendium: Continuing Education for Veterinarians® | March 2009 | CompendiumVet.com
- 31. FREE Vomiting CE patients undergoing phenothiazine therapy barrier. They have a short duration of action because of the vasodilatory properties of and can cause excitement in cats. Peripherally these drugs. acting anticholinergics include propantheline and methscopolamine. Isopropamide and pro- Anticholinergics pantheline are the drugs in this group that are Anticholinergic drugs block cholinergic afferent most commonly used in small animals for vom- pathway transmission from the gastrointesti- iting related to motion sickness.25 Side effects nal tract (peripheral action) and the vestibular reported in humans and small animals include system to the emetic center (central action).9 xerostomia (dry mouth), sedation, visual distur- Scopolamine and isopropamide are centrally act- bances, drowsiness, dysphoria, confusion, gas- ing anticholinergics that cross the blood–brain trointestinal ileus, and disorientation.9,26 TABLE 1 Vomiting Reflex Components, Receptors, and Controlling Neurotransmitters and Medications Receptor Receptor Agonists Receptor Antagonists Chemoreceptor trigger zone D2-Dopaminergic Dopamine Metoclopramide Prochlorperazine Haloperidol Trimethobenzamide Acetylpromazine Droperidol Chlorpromazine M1-Cholinergic Acetylcholine Propantheline Chlorpromazine Methscopolamine Isopropamide Scopolamine Acetylpromazine Prochlorperazine H1-Histaminergic Histamine Diphenhydramine Prochlorperazine Acetylpromazine Dimenhydrinate Chlorpromazine Promethazine Meclizine α2-Adrenergic Norepinephrine Prochlorperazine Chlorpromazine Yohimbine Acetylpromazine QuickNotes 5-HT3-Serotonergic Serotonin Ondansetron Mirtazapine Metoclopramide Vomiting is a neuro- Dolasetron Propofol Granisetron logically mediated ENKμ,δ-Enkephalinergic Met-enkephalin Butorphanol Leu-enkephalin reflex that depends Neurokinin-1 antagonist Substance P Maropitant on neural or Emetic center humoral activation 5-HT1A-Serotonergic Serotonin Diphenhydramine Dimenhydrinate Meclizine of the emetic center. α2-Adrenergic Norepinephrine Prochlorperazine Chlorpromazine Yohimbine Glucocorticoid receptors Dexamethasone Cyproterone Mifepristone Neurokinin-1 antagonist Substance P Maropitant Vestibular apparatus M1-Cholinergic Acetylcholine Propantheline Chlorpromazine Methscopolamine Isopropamide Scopolamine Acetylpromazine Prochlorperazine H1-Histaminergic Histamine Diphenhydramine Prochlorperazine Cyclizine Dimenhydrinate Chlorpromazine Promethazine Meclizine Diazepam Vagal afferents 5-HT3-Serotonergic Serotonin Ondansetron Mirtazapine Granisetron Dolasetron Metoclopramide Neurokinin-1 antagonist Substance P Maropitant Vagal efferents D2-Dopaminergic Dopamine Metoclopramide Prochlorperazine Haloperidol Trimethobenzamide Acetylpromazine Droperidol Chlorpromazine 5-HT4-Serotonergic Cisapride Piboserod Metoclopramide Serotonin M2-Cholinergic Acetylcholine Propantheline Chlorpromazine Methscopolamine Isopropamide Scopolamine Acetylpromazine Prochlorperazine Motilin Erythromycin — Motilin CompendiumVet.com | March 2009 | Compendium: Continuing Education for Veterinarians® 125
- 32. FREE CE Vomiting Antihistamines at high concentrations.9,25 Metoclopramide is Antihistamines can intercept cholinergic and known for its potent dopaminergic antagonism, histaminic nerve transmission responsible for but trimethobenzamide, which is also a weak vestibular stimulation of the vomiting center.25 antihistamine, has not been a very effective anti- Drugs in this classification include diphen- dopaminergic agent clinically. Metoclopramide hydramine, dimenhydrinate, and meclizine. has more action on D2-dopaminergic recep- These drugs display H 1-antihistaminergic tors than trimethobenzamide and is 20 times properties and are mainly used to control the more potent than phenothiazines.7 As a result, clinical signs of motion sickness. Mild seda- metoclopramide should not be used in patients tion, xerostomia, and drowsiness are some of receiving dopamine.12 the adverse effects. Meclizine can be terato- Cisapride, another substituted benzamide, genic if administered at high doses.25 activates neuronal 5-HT4 receptors, which Cats do not have histamine receptors in the facilitates gastric emptying. Metoclopramide CRTZ, and antihistaminic drugs do not control also activates neuronal 5-HT4 receptors their vomiting.27 and blocks 5-HT3 -serotonergic receptors, increases the lower esophageal sphincter Serotonin Antagonists tone, and enhances aboral gastrointestinal Serotonin antagonists are specific inhibitors motility; therefore, these drugs are classi- of 5-HT-serotonergic receptors. They control fied as prokinetics as well.9 Adverse effects vomiting by acting on receptors located on of these drugs include CNS excitement and the periphery of vagal nerve terminals and behavioral changes, especially during rapid QuickNotes centrally on the CRTZ.25,26 These receptors intravenous administration or if given at high Antiemetics are are normally stimulated by serotonin released doses. Metoclopramide controls peripherally drugs that block from the enterochromaffin cells of the small induced and humorally mediated vomiting intestine in response to damage to the gastro- due to numerous conditions, but it should specific superficial intestinal mucosa. Ondansetron, a member of be avoided if gastrointestinal obstruction is cell receptor sites, this class of antiemetic drugs, has been shown suspected because its prokinetic properties consequently dis- to control vomiting in dogs28,29 and is used in could predispose these patients to gastric or rupting the vomiting dogs receiving radiation and chemotherapy intestinal perforation. This contraindication reflex. when metoclopramide and other antiemet- also applies to cisapride. ics fail to control vomiting.28,29 Dolasetron, another member of this group, acts on recep- Butyrophenone and Benzimidazole tors in the CRTZ.25 Both of these drugs are Derivatives used extensively in human medicine, and Butyrophenone derivatives (e.g., haloperidol, they seem to be safe antiemetic alternatives droperidol) are potent dopamine antagonists in veterinary medicine.30,31 However, they are in the CRTZ and are used as tranquilizers.9 not effective in controlling vomiting caused by Their side effects are very similar to those of motion sickness.25,26 phenothiazines. The benzimidazole deriva- Side effects of these drugs that have been tives antagonize dopamine receptors in the reported in people include electrocardiographic gastrointestinal smooth muscle and display changes, including PR and QT prolongation and prokinetic properties like those of metoclo- QRS widening, that are believed to be caused pramide,32 but their use in veterinary medicine by sodium channel blockage by dolasetron is minimal if any. metabolites. Diarrhea, headache, dizziness, and musculoskeletal pain have been reported as Opioids well. These medications can be expensive. Enkephalins—endogenous opiates belong- ing to the endorphin family—are believed to Substituted Benzamides have antiemetic properties. Neurons containing Substituted benzamides exert antiemetic effects enkephalins have been identified near the CRTZ through different mechanisms. Some, such as and the emetic center.33 Evidence suggests that metoclopramide and trimethobenzamide, antag- opioid κ and/or μ receptors are present in the onize dopamine receptors in the CNS and block vomiting center and are involved in inhibition 5-HT3-serotonergic receptors when administered of emesis in dogs and cats.34 Butorphanol, a pri- 126 Compendium: Continuing Education for Veterinarians® | March 2009 | CompendiumVet.com
- 33. FREE Vomiting CE TABLE 2 Most Common Antiemetics Used in Small Animal Medicine Drugs Site of Action Dosage Side Effects α2-Adrenergic antagonists Prochlorperazinea,13 CRTZ and emetic center Dogs and cats: 0.1–0.5 mg/kg SC or IM q6–8h Hypotension, sedation Chlorpromazinea,2,13 CRTZ and emetic center Dogs: 0.1–0.5 mg/kg SC, IM, or IV q6–8h Hypotension, sedation Cats: 0.2–0.5 mg/kg SC, IM, or IV q6–8h Yohimbinea,2 CRTZ and emetic center Dogs: 0.25–0.5 mg/kg SC or IM q12h Hypotension, sedation D2-Dopaminergic antagonists Metoclopramidea,2,13 CRTZ, GI smooth muscle Dogs: 0.1–0.4 mg/kg PO, SC, or IM q6h Extrapyramidal signs, constipation Cats: 0.2–0.4 mg/kg PO, or SC q6–8h CRI: 1–2 mg/kg/day Trimethobenzamide2,13 CRTZ Dogs: 3 mg/kg IM q8–12h Allergic reactions H1-Histaminergic antagonists Diphenhydraminea,2,13 CRTZ Dogs and cats: 2–4 mg/kg PO or IM q8h Sedation, GI effects a,2,13 Dimenhydrinate CRTZ Dogs and cats: 4–8 mg/kg PO q8h Sedation, GI effects a Meclizine CRTZ Dogs and cats: 4 mg/kg PO q24h Sedation, xerostomia, tachycardia M1-Cholinergic antagonists Propanthelinea Parasympathetic nervous system Dogs and cats: 0.25 mg/kg PO q8h Gastric retention, ileus, tachycardia Isopropamideb Parasympathetic nervous system Dogs and cats: 0.2–0.4 mg/kg PO q8–12h Gastric retention, ileus, tachycardia 5-HT3-Serotonergic antagonists Ondansetrona,2 CRTZ and vagal afferent neurons Dogs: 0.11–0.176 mg/kg slow IV push q24h Sedation Cats: 0.1–0.15 mg/kg slow IV push q24h Dolasetrona CRTZ Dogs: 0.6 mg/kg IV q24h or 0.5 mg/kg PO, SC, or IV q24h Electrocardiogram changes Cats: 0.6 mg/kg IV q12h or 0.6–1 mg/kg PO q12h Mirtazapinea CRTZ and vagal afferent neurons Dogs: 0.6 mg/kg PO q24h, not to exceed 30 mg/day Sedation, ataxia, depression, vocalization Cats: 3–4 mg/cat PO q72h NK1-Neurokinin antagonist Maropitant40 CRTZ and emetic center Dogs: 1 mg/kg SC q24h up to 5 days or 2 mg/kg PO q24h up Injection site soreness, ataxia, anorexia, to 5 days diarrhea 5-HT4-Serotonergic antagonist Cisapridea,2 Myenteric neurons Dogs: 0.1–0.5 mg/kg PO q8h None Cats: 0.1–1.0 mg/kg or 5 mg (total dose) PO q8–12h Motilin agonist Erythromycina,2 GI smooth muscle Dogs and cats: 0.5–1.0 mg/kg IV q8h, up to 5.0 mg/kg PO q8h Vomiting at antimicrobial doses (15 mg/ kg tid) Opioid Butorphanola,13 Emetic center Dogs: 0.2–0.4 mg/kg IM 30 min before cisplatin infusion Sedation, ataxia, anorexia, diarrhea Others Propofola CRTZ None reported in veterinary medicine Apnea, hypotension, seizurelike signs 13 Dexamethasone Emetic center, medulla Dogs: 0.1 mg/kg SC or IV before chemotherapy GI ulceration a Diazepam Vestibular system suppression 0.1–0.2 mg/kg PO q6h Sedation a Plumb DC. Veterinarian Drug Handbook. 6th ed. Ames, IA: Wiley-Blackwell; 2008. b Richter KP. Treating acute vomiting in dogs and cats. Vet Med 1992;87(8):814-818. CompendiumVet.com | March 2009 | Compendium: Continuing Education for Veterinarians® 127
- 34. FREE CE Vomiting marily κ and σ agonist, is used to prevent vomit- Mirtazapine is a piperazinoazepine drug used ing related to cisplatin therapy in dogs.35,36 as an antidepressant in people. It antagonizes central presynaptic α 2-receptors and blocks Neurokinin Antagonists serotonin receptors.50 It is a weak 5-HT1 sero- Neurokinin (NK1) antagonists are a new group tonin receptor antagonist, a potent 5-HT2 and of antiemetics that includes maropitant, an agent 5-HT3 serotonin receptor antagonist, and an developed for dogs that acts as a ligand for the H1-histamine antagonist.50 It is used to control substance P receptors located in many areas chemotherapy-associated nausea and vomiting in of the brain, including the emetic center and humans50,51 and, more recently, in small animals. CRTZ.37 It is believed that the substance P–NK1 receptor complex is in the final common path- Treatment of Common Vomiting Conditions way of the neural and humoral pathways of the BOX 1 lists several conditions and diseases that vomiting reflex.38 Studies in dogs have showed commonly cause vomiting. that maropitant prevents vomiting caused by peripheral and central emetogens, including Gastritis or Gastric Ulceration apomorphine, cisplatin, and syrup of ipecac,39 Treatment to manage vomiting caused by gas- and clinical conditions such as pancreatitis tritis or gastric ulceration must include proper and gastroenteritis.39 Maropitant is also effec- fluid therapy and gastric mucosal protection. tive against vomiting caused by motion sick- Many clinicians use broad-spectrum antiemetics ness.39 Adverse effects reported with this drug because they cover local and peripheral recep- include ataxia, anorexia, diarrhea, and injection tors. Chlorpromazine, serotonin antagonists, and QuickNotes site soreness.40 This drug should not be used in metoclopramide are good options. Maropitant Phenothiazines are dogs younger than 16 weeks because bone mar- seems to work extremely well in dogs. If vomit- broad-spectrum row hypoplasia has been reported.40 ing is associated with gastrointestinal ulceration due to NSAID administration, therapy with antiemetics that Other Drugs misoprostol, a prostaglandin E1 (PGE) analog, have antidopamin- Other drugs used to control vomiting centrally may be effective in controlling both the ulcer- ergic and antihista- include yohimbine, diazepam, dexamethasone, ative lesion and vomiting as a secondary prob- minergic properties propofol, and mirtazapine. Yohimbine, a pure lem.52 Proton pump inhibitors and H2-histamine in the CRTZ and α2-adrenergic antagonist, is a very potent antiemetic antagonists provide more complete inhibition of anticholinergic used in dogs and cats. It may cause CNS excitement, gastric acid secretion in severe cases of ulcer- effects in the emetic excessive sedation, muscle tremors, tachypnea, pty- ation.12,25,53 If Helicobacter spp are the underly- center. alism, and hyperemic mucous membranes.36 ing cause of ulceration, appropriate antibiotic Diazepam relieves nausea and vomiting in therapy and antacids should relieve the clinical people.41 Studies with animal models and clin- signs of the infection. ical trials in human medicine suggest that this Patients with neoplastic diseases often have drug suppresses the vestibular system.41–43 gastrointestinal ulceration. Mast cell tumors of The antiemetic properties of corticosteroids any stage, grade, and size can cause vomit- are incompletely understood, but their mecha- ing in dogs by increasing the plasma hista- nism involves the activation of glucocorticoid mine concentration.16,54 Histamine acts on the receptors in the medulla, especially the emetic CRTZ and the gastric mucosa. Mast cell tumor center in cats.44 Dexamethasone has been ulceration and its effects are treated with shown to be useful in controlling chemother- H2-histamine antagonists. Tumor size and his- apy-associated nausea and vomiting in human tamine release in dogs are controlled with the patients45 and dogs.45,46 administration of corticosteroids.12,55 Propofol, an alkylphenol derivative, is used as an antiemetic in people with chemotherapy-asso- Pancreatitis ciated nausea and vomiting that is unresponsive Pancreatitis causes ileus due to intestinal to serotonin antagonists or dexamethasone.47,48 It inflammation, resulting in direct afferent input has been proposed that its antiemetic mechanism to the vomiting center.12 Metoclopramide is the involves reduction of the serotonin concentration most common antiemetic used in these patients in the CRTZ via γ-aminobutyric acid activity and because it acts centrally and peripherally. In 5-HT3 serotonin receptor antagonism.49 dogs, phenothiazines, 5-HT 3 -serotonergic 128 Compendium: Continuing Education for Veterinarians® | March 2009 | CompendiumVet.com
- 35. FREE Vomiting CE antagonists, and maropitant can be useful if ing inputs from the two vestibular systems (the metoclopramide fails to control vomiting. semicircular canals and the otolith organs); or (3) comparison of input from these systems Chemotherapy and Other Drugs with the individual’s expectations derived Emesis caused by cancer chemotherapy and from previous experiences.59 Vomiting caused other drugs (e.g., digitalis) is mediated by by motion sickness involves M1-cholinergic 5-HT3-serotonergic receptors.2,12,25 In humans, and H1-histaminergic receptors,2,11 and treat- the chemotherapeutic drugs most commonly ment should antagonize both receptors. associated with vomiting include cisplatin, Phenothiazines like chlorpromazine and cyclophosphamide, dacarbazine, and doxorubi- prochlorperazine can antagonize both receptors cin.56 Drugs with 5-HT3-serotonergic antagonist at the same time, but diphenhydramine, dimen- properties, especially the serotonin antago- hydrinate, cyclizine, meclizine, and promethaz- nists ondansetron, granisetron, dolasetron, ine are H1-histamine blocking agents only, and block these receptors in the CRTZ in cats and they should be combined with a M1-cholinergic in the vagal afferent neurons in dogs.25,26,28,29,57 receptor blocker for effective control of emetic Metoclopramide is widely used to control signals originating from the vestibular appara- chemotherapy-induced vomiting.6,58 The new tus. Maropitant prevents kinetosis in dogs by agent maropitant is also effective in controlling blocking the final common pathways of the cisplatin-induced vomiting in dogs, and even vomiting reflex, including signals from the ves- though there is coexpression of substance P tibular system.40 Scopolamine is a muscarinic with 5-HT receptors in the primate brain,37 this M1-cholinergic antagonist used to treat motion has not been documented in dogs or cats. sickness, but results are not consistent. QuickNotes Vomiting caused Motion Sickness Uremia by motion sick- Motion sickness, or kinetosis, is generated from Uremic toxins cause decreased gastrin clear- ness involves the vestibular apparatus.2,9,11 Studies in humans ance and irritate the gastrointestinal mucosa, have revealed that motion sickness is caused by resulting in ulcerative lesions and gastritis. M1-cholinergic and three mechanisms: (1) conflicting inputs from When these toxins cross the blood–brain H1-histaminergic the visual and vestibular systems; (2) conflict- barrier, they stimulate central and peripheral receptors, and treat- receptors and activate D2-dopaminergic recep- ment should antago- BOX 1 tors in the CRTZ.2,11 Dopamine antagonists nize both receptors. like metoclopramide and chlorpromazine Most Common Causes of effectively block these receptors. Vomiting in Dogs and Cats Diuresis with appropriate fluid therapy and a proton pump inhibitor or H2-histaminergic Abdominal disorders antagonist helps relieve uremia by diminish- Dietary factors ing the secretion of hydrogen ions into the Disorders of the small and large intestines stomach, providing protection and promoting Disorders of the stomach mucosal healing. Drugsa Endocrine disorders Gastrointestinal Motility Disorders ❯ Hypoadrenocorticism Prokinetics—cisapride, metoclopramide, and ❯ Hypoparathyroidism erythromycin—should be used to control vom- Neurologic disorders iting due to nonobstructive delayed gastric Parasitism emptying. These drugs exert their effects on ❯ Ollulanus tricuspis in cats different receptors. Cisapride, the most effective ❯ Physaloptera prokinetic agent available,11 lacks direct anti- ❯ Salmon poisoning (Neorickettsia helminthoeca) emetic effects but stimulates 5-HT4-serotonergic Systemic diseases receptors.60 Metoclopramide’s antagonism of Toxins, chemicals, and poisons D2-dopaminergic receptors enables it to stimu- a late motility in areas where these receptors are Almost any drug can cause vomiting, especially if given orally. present (the higher gastrointestinal tract, lower esophageal sphincter, stomach, and duode- CompendiumVet.com | March 2009 | Compendium: Continuing Education for Veterinarians® 129
- 36. FREE CE Vomiting num).2,11 Erythromycin, a macrolide used for its Undetermined Etiology antimicrobial properties, is useful as a prokinetic Patients with vomiting of undetermined etiology at low doses.2,11 In dogs, it stimulates the release must be treated with the safest approach pos- of motilin, which initiates phase III of the migrat- sible once systemic diseases (e.g., liver disease, ing myoelectric complex,61,62 the sequence of renal disease, endocrine disease) have been motor activity during the interdigestive period in ruled out. Patients that are uncomfortable from the small bowel.63 This cyclic pattern originates excessive vomiting or are at high risk for aspira- in the gastric antrum and extends over the entire tion pneumonia and have not been exposed to length of the small intestine.62,63 The third and a toxic agent should be treated with antiemetics final phase of this pattern is generally associated when available. α2-Adrenergic antagonists and with the propulsion of ingesta.64,65 It is unknown D2-dopaminergic receptors are first-line anti- whether cats can benefit from this effect. emetics. Maropitant is a good alternative not Dogs that vomit bile in the morning before only because it seems to block impulses in the eating may have bilious vomiting syndrome. final common pathways of the vomiting reflex This is a condition characterized by grass inges- but also because it is administered once daily, tion, vomiting, and lack of other definitive clin- dogs seem to tolerate it fairly well, and, so far, ical signs. It mostly occurs in the morning and adverse effects are minimal. 5-HT3-serotonergic is believed to be commonly associated with antagonists have become very popular over the gastritis, inflammatory bowel disease, and bile past few years and have good results. The addi- and gastroesophageal reflux. Affected patients tion of other drugs to antiemetic therapy should usually respond to a single evening dose of be considered if vomiting becomes refractory QuickNotes cisapride, metoclopramide, or erythromycin. in these patients. 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J Otolar- 56. American Cancer Society. Nausea and vomiting. Accessed January 2009 at cancer.org/do- yngol 1982;11(4):253-259. croot/MBC/content/MBC_2X_Nausea_and_Vomiting.asp?sitearea=MBC. 42. Sekitani T, McCabe BF, Ryu JH. Drug effects on the medical vestibular nucleus. Arch Otolaryngol 57. Tucker ML, Jackson MR, Scales MDC, et al. Ondansetron: pre-clinical safety evaluation. Eur 1971;93:581-589. J Cancer Clin Oncol 1989;25:S79. 43. Zanjoc TP, Roland PS. Vertigo and motion sickness. Part II: pharmacologic treatment. Ear 58. Ogilvie GK, Moore AS, Curtis CR. Evaluation of cisplatin-induced emesis in dogs with ma- Nose Throat J 2006;85(1):25-35. lignant neoplasia: 115 cases (1984-1987). JAVMA 1989;195:1399. 44. Ho GM, Ho ST, Wang JJ, et al. Dexamethasone has a central antiemetic mechanism in decer- 59. Eyeson-Annan M, Peterken C, Brown B, et al. Visual and vestibular components of motion ebrated cats. Anesth Analg 2004;99(3):734-739. sickness. Aviat Space Environ Med 1996;67(10):955-962. 45. Dexamethasone alone or in combination with ondansetron for the prevention of delayed 60. Gullikson GW, Loeffler RF, Viriña AM. Relationship of serotonin-3 receptor antagonist activ- nausea and vomiting induced by chemotherapy. The Italian Group for Antiemetic Research. N ity to gastric emptying and motor-stimulating actions of prokinetic drugs in dogs. J Pharmacol Engl J Med 2000;342(21):1554-1559. Exp Ther 1991;258:103. 46. Fukui H, Yamamoto M. Methotrexate produces delayed emesis in dog: a potential model of 61. Itoh Z. Erythromycin mimics exogenous motilin in gastrointestinal contractile activity in the delayed emesis induced by chemotherapy. Eur J Pharmacol 1999;372:261-267. dog. Am J Physiol 1984;247:G688. 47. Borgeat A, Wilder-Smith OH, Saiah M, et al. Subhypnotic doses of propofol possess direct 62. Granger DN, Barrowman JA, Kvietys PR. Clinical Gastrointestinal Physiology: A Saunders antiemetic properties. Anesth Analg 1992;74:539-541. Monograph in Physiology. Philadelphia: WB Saunders; 1985. 48. Gan TJ, El-Molem H, Ray J, et al. Patient-controlled antiemesis: a randomized, double-blind 63. Thomas EA, Sjovall H, Borstein JC. Computational model of the migrating motor complex comparison of two doses of propofol versus placebo. Anesthesiology 1999;90:1564-1570. of the small intestine. Am J Physiol Gastrointest Liver Physiol 2004;286(4):G564-G572. 49. Cechetto DF, Daib T, Gibson CJ, Gelb AW. The effect of propofol in the area postrema in rats. 64. Kruis W, Azpiroz F, Phillips SF. Contractile patterns and transit of fluid in canine terminal Anesth Analg 2001;92:934-942. ileum. Am J Physiol 1985;249(2 Pt 1):G264-G270. 50. Pae C. Low-dose mirtazapine may be successful treatment option for severe nausea vomit- 65. v Schönfeld J, Evans DF, Goebell H, et al. Comparison of the small bowel motor response to ing. Prog Neuropsychopharmacol Biol Psychiatry 2006;30:1143-1145. solid and liquid meals in man. Digestion 1997;58(4):402-406. 3 CE CREDITS CE TEST 1 This article qualifies for 3 contact hours of continuing education credit from the Auburn University College of Veterinary Medicine. Subscribers may take individual CE tests online and get real-time scores at CompendiumVet.com. Those who wish to apply this credit to fulfill state relicensure requirements should consult their respective state authorities regarding the applicability of this program. 1. Emesis is initiated, controlled, regulated, b. M1-cholinergic 8. ___________ can be used for chemother- and organized by the c. H2-histaminergic apy-associated nausea and/or vomiting, a. higher centers of the brain. d. 5-HT3-serotonergic especially when patients do not respond b. CRTZ. to the newer serotonin antagonists and c. vestibular apparatus. 5. Which antiemetic is also classified as a when multiple medication therapy fails. d. emetic center. prokinetic? a. Propofol a. ranitidine b. Diazepam 2. The vomiting pathways are controlled by b maropitant c. Mirtazapine a. neurotransmitter–receptor interactions. c. metoclopramide d. Dexamethasone b. the higher centers of the brain. d. propofol c. the peripheral nervous system. 9. Which antiemetic antagonizes neuroki- d. vestibular neurons. 6. Which condition or pathogen is the least nin receptors in many areas of the brain? likely to cause gastric ulceration? a. mirtazapine 3. ___________ are considered broad- a. Helicobacter spp b. maropitant spectrum antiemetics because of their b. mast cell tumor c. dolasetron effect on multiple receptors. c. gastrinoma d. prochlorperazine a. Anticholinergics d. kinetosis b. Phenothiazines 10. Select the correct antiemetic–adverse c. Serotonin antagonists 7. Mirtazapine does not antagonize effect pair. d. Opioids ___________ receptors. a. ondansetron; renal toxicity a. H1-histaminergic b. chlorpromazine; hypotension 4. Emesis caused by cancer chemotherapy b. 5-HT3-serotonergic c. metoclopramide; sedation and other drugs is mediated by c. central presynaptic α2- d. meclizine; gastrointestinal perforation ___________ receptors. d. D2-dopaminergic a. D2-dopaminergic CompendiumVet.com | March 2009 | Compendium: Continuing Education for Veterinarians® 131
- 38. Product Forum Digital Imaging System effective in the treatment of Cushing’s syndrome in dogs. The product The newly designed IDEXX-CR will be indicated for use in pituitary-dependent hyperadrenocorticism, 1417 Model 140 Digital Imaging which causes most cases of Cushing’s syndrome in dogs. It is the first System offers improved resolution drug to receive a Minor Use designation for the treatment of hyperad- and tissue contrast in addition to renocorticism caused by adrenal tumors in dogs. easy-to-use controls. Considered a Dechra Veterinary Products | 866-933-2472 | www.dechra-us.com very flexible system, it can be easily adjusted for different-sized ani- mals. The Model 140 is preconfigured to integrate with leading prac- tice management software packages, including IDEXX Cornerstone. Handheld Ultrasound IDEXX Laboratories | 877-433-9922 | www.idexx.com Northgate Veterinary Supply claims that the Ultra- EZ Scan personal ultrasound is the world’s first palm-sized, high-performance ultrasound system. Nitrile Gloves It offers high-quality image resolution, long battery Henry Schein’s Criterion Pure Nitrile life, and quick startup. Images can be zoomed in or Gloves are latex-free and meet ASTM D out, identified on the touch screen or by simultane- 6319-00a standards. These gloves help ous voice recorder, and downloaded to computers. A 1-year warranty prevent type IV allergic reactions because and tutorial disk are included, with free software upgrades available. they do not contain thiurams, carbamates, Northgate Veterinary Supply or thiazole. Textured fingers provide an 888-364-2243 | www.northgatevetsupply.com optimum grip in both dry and wet conditions, and the delicate-touch nitrile provides tactile sensitivity. The gloves come in five sizes. Henry Schein Animal Health Pet Supplements 800-872-4346 | www.henryscheinanimalhealth.com PetLabs360 offers nutritional supplements for dogs with arthritis, as well as those with excessive shedding problems. Arthogen Cushing’s Syndrome Plus is a blend of glucosamine HCI, chon- Medication droitin sulfate, hyaluronic acid, and methyl- Dechra Veterinary Products has sulfonymethane. It is designed to control received FDA approval to market inflammation and promote joint health. The Shed No More supplement VETORYL capsules. VETORYL is a blend of vitamins and minerals created to help provide dogs with a contains trilostane, which has healthy skin and coat. been demonstrated to be PetLabs360 | 888-738-7360 | www.petlabs360.com The product information presented here is provided by the manufacturers and does not reflect endorsement by Compendium. Understanding CONTINUED FROM PAGE 121 FHS can be controlled but is not likely to be Behavior Conclusion cured. By developing a clear diagnostic plan and following it closely, veterinarians can FHS has multiple possible etiologies. It requires avoid confusion for the owner and foster a patience and close communication with the sense of cooperation between the owner and pet’s owner in order to arrive at the correct themselves. Overall, this is the true measure diagnosis. As with most behavior disorders, of success. References 5. Tail chasing and spinning: canine and feline. In: Horwitz D, Neilson J. 1. Fears, anxieties and stereotypes. In: Overall K. Clinical Behav- Blackwell’s Five-Minute Veterinary Consult Clinical Companion: Canine ioral Medicine for Small Animals. St. Louis: Mosby; 1997:227. and Feline Behavior. Ames: Blackwell Publishing; 2007:475-483. 2. Lundgren B. Feline hyperesthesia syndrome. Accessed January 6. Selective serotonin reuptake inhibitors. In: Crowell-Davis S, 2009 at VeterinaryPartner.com. Murray T. Veterinary Psychopharmacology. Ames: Blackwell Pub- 3. Psychogenic alopecia/overgrooming: feline. In: Horwitz D, Neilson J. lishing; 2006:80-110. Blackwell’s Five-Minute Veterinary Consult Clinical Companion: Canine 7. Tricyclic antidepressants. In: Crowell-Davis S, Murray T. Veterinary and Feline Behavior. Ames: Blackwell Publishing; 2007:425-431. Psychopharmacology. Ames: Blackwell Publishing; 2006:179-206. 4. Opioids and opioid antagonists. In: Crowell-Davis S, Murray T. Veteri- 8. Benzodiazepines. In: Crowell-Davis S, Murray T. Veterinary Psy- nary Psychopharmacology. Ames: Blackwell Publishing; 2006:212. chopharmacology. Ames: Blackwell Publishing; 2006:34-71. 132 Compendium: Continuing Education for Veterinarians® | March 2009 | CompendiumVet.com
- 39. CE Article 2 3 CE CREDITS Squamous Cell Carcinoma ❯❯ Julie L. Webb, DVM, DACVP Abstract: Squamous cell carcinoma (SCC) is a relatively common, malignant neoplasm of dogs ❯❯ Rachel E. Burns, DVM and cats that can arise in a variety of locations. The gross appearance of SCC can be variable and ❯❯ Holly M. Brown, DVM nonspecific, so definitive diagnosis requires microscopic examination of the tissue (cytology or ❯❯ Bruce E. LeRoy, DVM, PhD, histology). Several treatment modalities exist, but surgical excision, if possible, is regarded as the DACVPa best treatment option. Early diagnosis and treatment of SCC are key because small, early-stage ❯❯ Carrie E. Kosarek, DVM, tumors are the most amenable to treatment and carry the best prognosis. MS, DACVIM (Oncology) S quamous cell carcinoma (SCC) is a conjunctiva, cornea, nasal passages, larynx, The University of Georgia malignant neoplasm arising from lung, esophagus, bladder, prostate, penis, squamous epithelium. The skin, oral cervix, vagina, and anal sac.1,8,9 cavity, and digits are the most common sites Most SCCs are locally invasive and, in of SCC in dogs and cats.1 SCCs account for certain areas of the body, exhibit bone inva- 15% of skin tumors in cats.2 Most cutaneous sion and osteolysis. Tumor spread to local SCCs in cats occur on the head (FIGURE 1), lymph nodes may occur, but distant metas- often involving the pinna, eyelid, and nasal tases are rare and usually do not occur until planum.2 In dogs, less than 5% of cutane- late in the disease process. However, cer- ous neoplasms are SCC, and common sites tain anatomic locations have a higher rate include the legs, scrotum, perineum, nasal of metastasis. TABLE 1 lists some common At a Glance planum, and various lightly pigmented sites of SCC and the biologic behavior asso- Risk Factors and Etiology areas.1,3 SCCs account for 70% of feline and ciated with those sites.1 Page 134 25% of canine oral neoplasms and may arise A premalignant form of SCC, composed from virtually any surface in the oral cavity, of dysplastic cells that do not cross the epi- Common Locations including the gingiva (FIGURE 2), tongue, ton- thelial basement membrane, is called SCC and Associated Biologic Behavior of SCC sils, pharynx, lips, and buccal mucosa.1 In a in situ.10 Complete excision of an SCC in situ Page 134 retrospective series evaluating lingual lesions is curative for that lesion, but new lesions in dogs, more than one-half of the lesions may develop in other areas. Two forms of Gross Description were neoplastic, and 17% of those neo- SCC in situ have been reported in dogs and and Clinical Signs Page 135 plasms were SCC.4 Of digital tumors in dogs cats: solar keratosis and multicentric SCC (FIGURE 3), 38% to 50% are SCC, and multi- in situ (MSCC). The lesions of solar kerato- Diagnosis ple digits may be involved.5,6 Digital SCC was sis are usually singular and range from an Page 136 previously reported to be rare in cats, but a erythematous, scaly thickening of the skin Distinguishing Features recent study diagnosed SCC in 24% of ampu- to shallow, crusting lesions. They occur on of Cytologic Samples That tated feline digits.7 Other locations reported lightly haired, nonpigmented skin and are Contain Squamous Cells to develop SCC in dogs and cats include the associated with ultraviolet (UV) light expo- Page 137 Treatment Options Courtesy of Carrie E. Kosarek, DVM, MS, DACVIM (Oncology) FIGURE 1 FIGURE 2 and Prognosis Page 137 Courtesy of Dr. Kosarek a Dr. LeRoy discloses that he has received financial support from Novartis Animal Health and Pfiz- er Animal Health. Periocular SCC in a cat. Maxillary gingival SCC in a dog. CompendiumVet.com | March 2009 | Compendium: Continuing Education for Veterinarians® 133
- 40. FREE CE Squamous Cell Carcinoma FIGURE 3 sure.3 With time and continued The mechanism frequently proposed for exposure to UV light, most solar cutaneous SCC and its association with UV light keratosis lesions can progress to involves the tumor suppressor gene p53.13 This SCC. MSCC, similar to Bowen’s gene encodes a protein (p53) that arrests the cell disease in humans, presents as cycle when DNA damage is present, giving the multiple plaque-like or papillary cell time to repair the damage before continu- lesions on pigmented, haired ing mitosis. If the damage cannot be repaired, skin and is not related to UV p53 will induce apoptosis of the cell. UV light is light exposure. MSCC is rare in a common carcinogen that can mutate the p53 cats and very rare in dogs.1,10 Its gene. Cells in which the p53 gene is mutated progression to SCC seems to be continue replication even if DNA damage is pres- slow, if it occurs at all. ent, leading to the accumulation of other muta- Courtesy of Dr. Kosarek tions and a greater chance of neoplasia.13 The Risk Factors and Etiology mutant form of p53 has been detected in 82% of Older animals are at greater risk feline pinna SCCs, emphasizing the importance for developing SCC, with the of p53 in preventing solar-induced SCC.13 average age at presentation being Few studies investigating carcinogens that Digital SCC in a dog. 8 to 10 years for dogs and 10 to may contribute to the development of SCC in 12 years for cats.2,3,10 Prolonged cats and dogs have been conducted. Reported exposure to UV light, lack of skin pigment, and risk factors for oral SCC in cats include wearing a sparse haircoat all contribute to the develop- flea collars and eating canned food (especially ment of cutaneous SCC.1 Siamese cats, with tuna-based food).14 Small but statistically insig- their pigmented extremities, may be less likely nificant correlations have been found between to develop cutaneous SCC.2 Cats with long hair- environmental tobacco smoke and feline oral coats, such as Himalayans and Persians, also SCC.14,15 Urban pollutants may increase the risk have a decreased risk, whereas domestic short- for tonsillar SCC.3 haired cats are overrepresented.1 Dogs with Another potential contributor to the devel- white haircoats are more susceptible to cuta- opment of SCC in dogs and cats is chronic neous SCC, whereas dogs with dark haircoats inflammation. Chronic dermatosis is a reported appear to be overrepresented in cases of digi- risk factor for cutaneous SCC,16 and, although tal tumors.1,6 Rarely has a sex predilection been extremely rare, bilateral aural SCC was reported reported; in one study, female dogs appeared to in two dogs that had a history of chronic aural be at increased risk for development of lingual inflammation.17 In addition, multiple corneal SCC4, while tonsillar SCC may be more common SCCs developed in a dog with keratoconjunc- in male dogs.11,12 tivitis sicca.18 TABLE 1 Common Locations and Associated Biologic Behavior of SCC Tumor Location Local Regional Lymph Distant Comments Invasion Node Spread Metastasis Skin Frequent Rare Rare Lymph node spread mostly occurs in poorly differentiated tumors or those present for longer periods Gingiva Frequent Rare Rare Frequent bone invasion and destruction Tongue Frequent Common Rare Local recurrence common after surgical removal Tonsil Frequent Frequent Common Lungs, liver, and spleen are the most common metastatic sites Cheek/Lip Common Rare Rare — Nasal passages Frequent Rare Rare Bone invasion common Lung Frequent Common Common Solitary or multiple masses; metastases to one or multiple digits reported in cats Digit Frequent Common Common Bone invasion and destruction common; lungs are the most common metastatic site 134 Compendium: Continuing Education for Veterinarians® | March 2009 | CompendiumVet.com
- 41. FREE Squamous Cell Carcinoma CE FIGURE 4 FIGURE 5 Courtesy of Julie L. Webb, DVM, DACVP Courtesy of Dr. Webb Fine-needle aspirate from a cutaneous SCC. Asynchronous maturation in a neoplastic A small cluster of cells displays anisocytosis, aniso- squamous cell. The mature, fully keratinized cell karyosis, multinucleation, prominent nucleoli (thin has retained a large nucleus (arrow; Wright’s stain, arrow), keratohyaline granules (thick arrow), and 1000×). emperipolesis (arrowhead; Wright’s stain, 1000×). Viral etiologies have been linked to certain Deeply ulcerated lesion SCCs in people. Papillomavirus type 16 infection Proliferative, raised, red plaque is associated with a significant number of SCCs Cauliflower-shaped growth of the head and neck in humans, particularly in the oropharynx and in patients lacking the risk The appearance of the lesion may change factors of tobacco and alcohol consumption.19 over time, often progressing from a shallow or QuickNotes Papillomavirus DNA has been detected within ulcerated lesion to a more proliferative, raised approximately 20% of canine and feline cutane- tumor. The time from lesion occurrence to diag- The most common ous and mucosal SCCs, but the significance of nosis also varies but is generally prolonged. In locations for cats this association has yet to be determined.20,21 two studies of cats with SCC of the nasal pla- and dogs to develop Radiation-induced carcinogenesis is well doc- num or pinnae, lesions were reportedly present SCC are the skin, umented in people and animals, as reviewed for a median duration of 3 to 5 months before digits, and oral cav- by Suit and colleagues in 2007.22 In one study23 diagnosis.25,26 Often, the tumor is initially misdi- ity, but tumors may evaluating orthovoltage radiotherapy for the agnosed as an inflammatory or traumatic lesion, also arise at other treatment of acanthomatous epulides (now and therapies such as antibiotics and corticos- sites, including called acanthomatous ameloblastomas), seven teroids may have been used before diagnosis.25 the cornea, lungs, of 39 dogs (18%) developed second tumors Clinical signs of SCC depend on the tumor’s within the radiation field; 71% of the tumors location. Digital tumors often cause lameness and esophagus, and were SCC. However, a more recent study24 found ulceration of the digit.5 Nasal tumors can cause bladder. that the risk of developing a second tumor was facial deformity, nasal discharge, and sneezing. less than 4%. In this study, only two of 57 dogs Signs of oral tumors include excess salivation, that underwent definitive radiation therapy (RT) oral bleeding, anorexia, loose teeth, dysphagia, for acanthomatous epulides developed second weight loss, and halitosis.27 Numerous other clini- tumors, both of which were sarcomas. The cal signs have been reported: coughing and dys- authors of the more recent study suggest that pnea with pulmonary tumors, regurgitation with the earlier paper may have included patients esophageal masses, voice change with laryngeal whose original tumors were SCC, misdiagnosed SCC, and ocular discharge with periocular and as acanthomatous epulides. ocular tumors.1 Hypertrophic osteopathy is a rare complication with pulmonary SCC.28 Gross Description and Clinical Signs There are no consistent abnormal labora- In many cases of SCC, the animal presents with tory findings in animals with SCC. One study a visible mass. The mass may appear as any of found that 32% of cats with oral SCC had a the following3: neutrophilic leukocytosis, likely reflecting sec- Shallow crusting lesion (often SCC in situ) ondary infection of ulcerated masses.27 One CompendiumVet.com | March 2009 | Compendium: Continuing Education for Veterinarians® 135
- 42. FREE CE Squamous Cell Carcinoma FIGURE 6 FIGURE 7 Courtesy of Dr. Webb Courtesy of Dr. Webb Septic purulent inflammation with squamous cell hyperplasia. A small cluster of dysplastic squamous cells is surrounded by degenerate neutro- phils and numerous bacteria. The squamous cells dis- Tadpole cells in a cutaneous SCC aspirate play cytoplasmic basophilia and mild anisocytosis. A (Wright’s stain, 500×). binucleated cell is also present (Wright’s stain, 1000×). case of paraneoplastic neutrophilic leukocyto- As with other epithelial neoplasms, SCCs tend sis has been reported with pulmonary SCC,29 to exfoliate readily, leading to highly cellular and several cases of paraneoplastic hypercal- samples. The cells may be in closely adherent cemia have been documented.30 sheets or clusters, although numerous individual cells are often present. Squamous cells undergo QuickNotes Diagnosis several stages of maturation; thus, a pleomorphic Early diagnosis of SCC is paramount for early population of cells may be observed. Immature On initial presenta- therapeutic intervention, which may result in (basal-type) squamous cells are small, round tion, many SCCs long-term control or cure for affected patients. to cuboidal cells with a scant amount of glassy, are misdiagnosed SCC may be suspected based on the gross basophilic cytoplasm and a high nuclear–cyto- as inflammatory or appearance of a lesion and its location, but plasmic ratio. Mature (superficial) squamous traumatic lesions. definitive diagnosis requires microscopic exam- cells are large, angular cells with a large amount ination of the affected tissue. Cytology is a rapid, of lightly basophilic cytoplasm and pyknotic or easy, noninvasive method that may provide the absent nuclei.31 Keratinized cells have deeply diagnosis of SCC and is often attempted as the basophilic cytoplasm with angular borders. first diagnostic technique, especially for cutane- Poorly differentiated SCCs consist predominantly ous lesions. Biopsy with histopathology may be of immature cells, and well-differentiated tumors required to obtain a definitive diagnosis if cytol- contain more mature cells. ogy is nondiagnostic or equivocal. Asynchronous nuclear and cytoplasmic maturation, in which large, fully keratinized Cytology cells retain large nuclei, is commonly seen Several methods may be used to obtain a spec- with SCC (FIGURE 4). Other criteria of malig- imen for cytologic analysis. The best method nancy found in SCC include prominent aniso- depends on the lesion location and gross cytosis and anisokaryosis, multinucleated cells, appearance. Fine-needle aspiration is used to and variable numbers and sizes of nucleoli. obtain material from nodular lesions, whereas Keratohyaline granules are frequently present surface imprints and scrapings are often used as small, round, cytoplasmic vacuoles concen- to collect material from shallow or plaquelike trated around the nucleus. SCC cells may also lesions. Unfortunately, many SCCs are ulcer- display emperipolesis, in which other cells ated and inflamed, so superficial sampling are able to passively penetrate the neoplastic may retrieve only the inflammation and not squamous cell and are found within its cyto- the deeper neoplastic cells. Impression smears plasm31 (FIGURE 5). Cells with a long cytoplas- from biopsy samples also provide material for mic process resembling a tail, called tadpole cytologic examination. cells, are occasionally observed (FIGURE 6). 136 Compendium: Continuing Education for Veterinarians® | March 2009 | CompendiumVet.com
- 43. FREE Squamous Cell Carcinoma CE The cytologic diagnosis of SCC is often com- FIGURE 8 plicated by concurrent inflammation. Secondary inflammation, often present when the tumor is ulcerated, may mask the neoplastic cell popula- tion. Additionally, primary inflammatory condi- tions can induce epithelial hyperplasia, creating dysplastic changes, such as increased cytoplas- mic basophilia, anisocytosis, and anisokaryo- sis, that mimic neoplasia (FIGURE 7). Therefore, Courtesy of Dr. Webb extreme caution should be used when attempt- ing to diagnose SCC on cytology in a highly inflamed area. Histologic examination of the lesion may be necessary for a definitive diagno- sis in these situations. An aspirated sample from a follicular cyst (keratin- Other samples containing squamous cells, producing lesion) containing abundant, anucleate, keratinized such as contaminated slides, papillomas, and squamous cells and keratin debris (Wright’s stain, 200×). Grossly, keratin-producing cysts or tumors (FIGURE 8), these lesions contain caseous white material. must be differentiated from SCC on cytology. TABLE 2 details features that can help distin- analysis, urinalysis, local lymph node evalu- guish these lesions from SCC.31 ation, three-view thoracic radiography, and abdominal imaging (radiography and ultra- Histology sonography). The extent of staging that is under- Biopsy of the lesion and histologic analy- taken is often dictated by the primary tumor sis are often needed to definitively diagnose location. Advanced imaging techniques, such SCC, especially if the tumor is poorly differ- as computed tomography, may be required to entiated or highly inflamed. If not excisional, further define the location and extent of the the biopsy should always contain the junction primary tumor, especially for tumors involving of grossly normal and abnormal epithelium, the ear canal, oral, and sinonasal cavities.32–34 as this is usually the most diagnostic region. Imaging is also useful for surgical and radia- A typical well-differentiated SCC maintains a tion treatment planning. loose epithelial maturation sequence from basal layer to stratum corneum, but instead of Treatment Options and Prognosis growing toward the skin surface, the neoplas- Early diagnosis and implementation of therapy tic cells form irregular whorls and cords within is advised for all patients with SCC, especially the tumor (FIGURE 9). Nests of neoplastic cells because small tumors are more amenable to surrounded by stroma may have the equiva- lent of the basal cell layer at the outer edge of the nest and the keratin-producing layer in Distinguishing Features of Cytologic TABLE 2 the center, creating the classic appearance of Samples That Contain Squamous Cells intensely eosinophilic, densely packed rings of Lesion Cytologic Description keratin (a keratin pearl, FIGURE 10). In less dif- ferentiated tumors, epithelial layering is indis- SCCa Pleomorphic population of nucleated squamous tinct, cells are smaller, and keratinization is less cells with numerous features of malignancy likely to be seen. Highly anaplastic SCCs may Mature squamous cells lacking features of Papillomaa require special immunohistochemical stains, malignancy such as cytokeratin, to positively identify the cell of origin.1 Keratin-producing cyst Numerous anucleate squamous cells and keratin or tumorb (FIGURE 8) debris ± cholesterol crystals Staging Contaminated sample A few anucleate squamous cells and a small amount SCC is typically a locally aggressive neoplasm (often due to handling) of keratin debris with a variable potential for distant metastasis. a Diagnostic staging tests that may be advised It may be difficult to differentiate between a well-differentiated SCC and a papilloma on cytology. b Includes epidermal inclusion cysts, follicular cysts, pilomatrixomas, and trichoepitheliomas. include routine hematologic and biochemical CompendiumVet.com | March 2009 | Compendium: Continuing Education for Veterinarians® 137
- 44. FREE CE Squamous Cell Carcinoma FIGURE 9 are incompletely excised. It is inexpensive and readily available and provides excellent cos- metic results. Studies have reported that cryo- therapy provides good local control for 1 year or longer for SCCs of the cornea.18,36 For the pinna and nasal planum, cryotherapy provided a median disease-free interval of 254 days in 11 cats.25 In a larger study37 of cats with nasal pla- num SCC treated with cryotherapy, the median remission time was 26.7 months. Courtesy of Dr. Webb Radiation Therapy Definitive RT is a local treatment modality that is generally recommended as an adjuvant treat- ment for incompletely excised tumors or as a Nests of neoplastic squamous epithelium in a moderately differen- primary treatment for inoperable tumors. In the tiated SCC (hematoxylin–eosin stain, 400×). case of SCC, RT is most commonly employed for tumors of the nasal planum, nasal cavity, local control. Local treatment options for dogs and oral cavity. The response to definitive RT and cats with SCC include surgery, cryother- for dogs with oral SCC varies with the size of apy, RT, plesiotherapy, photodynamic therapy the tumor: small, early-stage tumors had the (PDT), and intratumoral chemotherapy. Systemic best response and the longest progression-free therapy, such as chemotherapy and cyclooxy- intervals38 (FIGURE 11). In cats with nasal planum genase-2 (COX-2) inhibitors, may be advised for SCC treated with definitive RT, the 1- and 5-year patients with SCCs that are inoperable, are poorly survival rates were 60% and 10%, respectively.39 differentiated, have metastasized at the time of In dogs, nasal planum tumors treated with RT diagnosis, or are in a location with a report- recurred in an average of 2 to 3 months, and edly aggressive biologic behavior (TABLE 1). It the median survival time was 6 months.40,41 The is important to note that, with certain forms of median survival time of eight dogs with tonsillar SCC (i.e., those induced by UV light), cellular SCC treated with surgery plus definitive RT was damage may already be present at other sites. 110 days.11 Protocols vary among institutions; QuickNotes Therefore, new lesions may develop even with however, most protocols involve low-dose frac- Many SCCs excellent local control of the primary lesion. tions (3 to 4 Gy) given daily to every other day are ulcerated over a 3- to 4-week period. The side effects of Surgical Excision these protocols are generally mild and limited and inflamed. Surgical excision is the primary treatment to acute reactions such as mucosal inflamma- Superficial sam- option for most patients with SCC. The ability tion. No radiation-induced tumors have been pling (impression to completely excise the tumor depends on fac- specifically reported with these protocols, but smears, scrapings, tors such as the size and location of the tumor. any RT has the potential to induce neoplasia. or swabs) may In a retrospective study25 evaluating response Palliative RT typically involves a total of three retrieve only the to therapy (surgery, RT, or cryotherapy) in 61 to four treatments given at a higher dose per inflammation and cats with nasal planum or pinna SCC, sur- fraction than definitive RT. The goals of pallia- miss the underlying gery provided the longest disease-free inter- tive RT are to provide pain relief, stabilize tumor val, with a median of 594 days. Early surgical growth, or improve dysfunction associated with neoplastic cells. intervention is also advised for digital tumors. the tumor. Palliative RT may be recommended Digital amputation resulted in complete tumor for patients for which a cure is not possible due control for all but one of 21 dogs with subun- to advanced local or metastatic disease or other gual SCC.35 If complete surgical excision is not severe illness. Unfortunately, reports evaluating possible, adjuvant therapies may be pursued. the efficacy of palliative RT in dogs and cats with SCC are limited, and the few that exist are Cryotherapy not encouraging. A 2001 study evaluating pal- Cryotherapy may be considered for local con- liative RT in seven cats with nonresectable oral trol of small, superficial tumors or tumors that SCC found that 87% of the cats had tumor pro- 138 Compendium: Continuing Education for Veterinarians® | March 2009 | CompendiumVet.com
- 45. FREE Squamous Cell Carcinoma CE gression or acute radiation side effects, with a FIGURE 10 mean survival time of only 60 days.42 Plesiotherapy Plesiotherapy involves the topical applica- tion of a radiation source to the target lesion. Topical radiation doses drop off significantly after a depth of 2 mm; therefore, the use of plesiotherapy is limited to superficial or incom- Courtesy of Dr. Webb pletely excised tumors, particularly those of the nasal planum or ocular region. In a recent retrospective study26 evaluating the efficacy of strontium-90 plesiotherapy for cats with nasal planum SCC, 13 of 15 cats achieved a complete response with a median disease-free interval A single nest of neoplastic squamous epithelial cells sur- of 692 days. Excellent cosmetic results were rounded by fibrous stroma (keratin pearl; hematoxylin–eosin stain, also obtained. Strontium-90 plesiotherapy has 400×). This is a common finding in well-differentiated SCCs. also been used to treat SCC in dogs.43 volume, and 62% of the dogs were euthanized Photodynamic Therapy because of progressive disease.12 PDT is yet another local treatment modality There are few reports of the use of intra- that has been used for treatment of SCC. The tumoral chemotherapy for cats and dogs with process involves the topical administration or SCC.48–50 Intratumoral therapy with a cisplatin intravenous injection of a photosensitizer that analog was ineffective in cats with oral SCC, preferentially accumulates in neoplastic cells. many of which experienced signs of toxicity Once activated by light of a specific wavelength, ranging from lethargy and inappetence to acute the photosensitizer causes cytotoxicity and tis- anaphylactoid reactions.49 In comparison, intra- sue necrosis. Studies of intravenous PDT 44,45 in tumoral treatment with carboplatin appeared dogs and cats with oral and cutaneous SCC have safe and effective for cats with nasal planum QuickNotes shown moderate to good response rates (62% SCC.48 In a study of 13 dogs with cutaneous SCC Surgical excision to 73% of patients experience a cure or good treated with intratumoral sustained-release is the treatment of local control) that last 1 year or longer. In a more chemotherapy (5-fluorouracil or cisplatin), all choice for SCC, but recent study46 evaluating topical PDT in cats with the dogs had a 50% or greater response, and a variety of local facial SCC, 85% achieved a complete response. 54% achieved a complete response.50 The mean Unfortunately, 63% of these cats developed disease-free interval was 153 weeks. The use and systemic treat- recurrence in a median time of 21 weeks. The of chemotherapeutics as sensitizers before RT ment modalities are results of these studies suggest that PDT may be has also been evaluated in dogs and cats with available to treat an effective local treatment modality, but PDT SCC. Cisplatin combined with RT has shown tumors that can- is not readily available in private practice. some promise in dogs with nasal SCC,51 while not be completely results of combining gemcitabine with RT are excised. Chemotherapy less encouraging.52,53 SCCs generally are not considered chemore- sponsive tumors; however, chemotherapy may COX-2 Inhibitors be considered under certain circumstances. COX-2 is an inducible enzyme responsible for For example, chemotherapy may be advised the production of inflammatory prostaglandins. for tumors that are inoperable, anaplastic, or Overexpression of COX-2 has been implicated metastatic at the time of diagnosis. Single-agent in the progression of certain cancers, specifi- or combination therapy protocols containing cally carcinomas. Several studies in dogs and bleomycin, cisplatin, carboplatin, cyclophos- cats have reported increased expression of phamide, doxorubicin, and 5-fluorouracil have COX-2 in SCCs in various locations.54–58 In light been evaluated.12,47 In 16 dogs with tonsillar of these findings, the role of COX-2 inhibitors SCC treated with multidrug chemotherapy, in the management of SCC needs to be further there was no appreciable reduction in tumor explored. CompendiumVet.com | March 2009 | Compendium: Continuing Education for Veterinarians® 139
- 46. FREE CE Squamous Cell Carcinoma FIGURE 11 In addition to their antiin- liver enzymes and neutropenia in one cat). Mandibular gingival SCC in a dog. flammatory effects, COX-2 Retinoids (vitamin A derivatives) have been inhibitors may have anti- evaluated for the treatment of solar-induced tumor properties. The use SCC and its associated preneoplastic lesions A of piroxicam, a nonspecific (solar keratosis). In a study assessing the effi- COX inhibitor, given alone cacy of etretinate for dogs with solar-induced or in combination with other preneoplastic lesions, five of 10 dogs showed a therapies has been evalu- partial or complete response.65 However, thera- ated in dogs with SCC.59–62 peutic efficacy of 13-cis-retinoic acid was not Schmidt and colleagues 60 evident in 10 cats with preneoplastic lesions or prospectively evaluated the SCC of the head.66 efficacy of daily oral piroxi- A multimodal approach to treating dogs and cam in 17 dogs with mea- cats with SCC may provide the most therapeutic surable oral SCC. Three benefit when surgery cannot be curative. The dogs obtained partial efficacy of a combination of surgery, carboplatin, or complete remission and RT was reported in five dogs with tonsil- for a median of 180 days; lar SCC: the mean survival time was 211 days.67 five other dogs had stable In an earlier study, five of six dogs with tonsil- B disease for a median of lar SCC treated with a combination of surgery, 102 days. A recent pharma- doxorubicin, cisplatin, and RT had a complete cokinetic study evaluat- response with a median disease-free interval of ing piroxicam in cats with 240 days.12 Carboplatin combined with RT has carcinoma suggested that also been employed for treatment of nasal pla- a dose of 0.3 mg/kg/day num SCC in cats with a good response (six of six PO would be appropri- cats had a complete response and no recurrence ate for clinical trial use in for up to 268 days).68 Further prospective studies cats with COX-2–positive evaluating multimodal therapy are warranted. oral SCC.58 Although these Courtesy of Dr. Kosarek studies have shown only Conclusion minimal toxicity (mild SCCs are common tumors of dogs and cats. vomiting or diarrhea in a They vary in appearance, location, and biologic (A) Before radiation therapy. (B) Two months after radiation therapy. few animals), it should be behavior; however, they are typically locally noted that, as a nonspe- aggressive, with a reported low to moderate cific COX inhibitor, piroxi- metastatic potential. Early recognition, diagnosis, cam can induce serious side effects, including and treatment are essential. Diagnosis of SCC gastrointestinal ulceration and renal failure. relies on cytologic or histologic examination of COX-2–selective inhibitors have a lower inci- the tumor. Many treatment modalities are avail- dence of these side effects, but, as yet, there able, with surgical excision being the mainstay are no studies evaluating their effect on SCC. of therapy. The prognosis for patients with SCC varies. A favorable prognosis exists for patients Novel and Multimodality Therapies with well-differentiated tumors that can be com- Immunotherapy, the stimulation of the immune pletely excised and without evidence of vascu- system to “reject” a tumor, has been employed lar or lymphatic invasion or distant metastases. in human medicine for treating a variety of Conversely, the prognosis is poor for patients cancers, including SCC. Experience with this with inoperable or poorly differentiated tumors therapy in small animal medicine is limited. or with metastatic disease. Further investiga- Imiquimod is a topical immunomodulator that tion into the tumorigenesis of SCC is warranted. induces cytokine production and may induce The findings of these studies may lead to addi- tumor apoptosis.63 In a small retrospective tional preventive measures and novel treatment study64 evaluating the efficacy and toxicity of modalities that improve outcomes for dogs and topical imiquimod in cats with MSCC, treatment cats with this type of cancer. appeared effective in all 12 cats and was associ- ated with mild toxicity (local erythema in three Acknowledgment: The authors thank Dr. C. G. Couto cats, partial anorexia in one cat, and increased for his editing assistance. 140 Compendium: Continuing Education for Veterinarians® | March 2009 | CompendiumVet.com
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Atlas of Canine and Feline Cytology. Philadelphia: WB Saun- for the treatment of oral malignant melanoma and oral squamous cell carcinoma in dogs. ders; 2001. JAVMA 2004;224(3):388-394. 32. Saunders JH, Van Bree H, Gielen I, et al. Diagnostic value of computed tomography in 62. Langova V, Mutsaers AJ, Phillips B, et al. Treatment of eight dogs with nasal tumors dogs with chronic nasal disease. Vet Radiol Ultrasound 2003;44(4):409-413. with alternating doses of doxorubicin and carboplatin in conjunction with oral piroxicam. Aust 33. Schoenborn WC, Wisner ER, Kass PP, et al. Retrospective assessment of comput- Vet J 2004;82(11):676-680. CompendiumVet.com | March 2009 | Compendium: Continuing Education for Veterinarians® 141
- 48. FREE CE Squamous Cell Carcinoma 63. Shon M, Schon MP. The antitumoral mode of action of imiquimod acid for the treatment of squamous cell carcinoma and preneoplastic and other imidazoquinolones. Curr Med Chem 2007;14(6):681-687. lesions of the head in cats. Am J Vet Res 1985;46(12):2553-2557. 64. Gill V, Bergman P, Baer K, et al. Evaluation of imiquimod 5% (Al- 67. Murphy S, Hayes A, Adams V, et al. Role of carboplatin in multi- dara) in cats with multicentric squamous cell carcinoma in situ (MSC- modality treatment of canine tonsillar squamous cell carcinoma—a CIS). Proc 26th Vet Cancer Soc 2006:18. case series of five dogs. J Small Anim Pract 2006;47(4):216-220. 65. Marks SL, Song MD, Stannard AA, et al. Clinical evaluation of etret- 68. De Vos JP, Burm AGO, Focker BP. Results from the treatment of inate for the treatment of canine solar-induced squamous cell carcino- advanced stage squamous cell carcinoma of the nasal planum in cats, ma and preneoplastic lesions. J Am Acad Dermatol 1992;27(1):11-16. using a combination of intralesional carboplatin and superficial radio- 66. Evans AG, Madewell BR, Stannard AL. A trial of 13-cis-retinoic therapy: a pilot study. Vet Comp Oncol 2004;2(2):75-81. 3 CE CREDITS CE TEST 2 This article qualifies for 3 contact hours of continuing education credit from the Auburn University College of Veterinary Medicine. Subscribers may take individual CE tests online and get real-time scores at CompendiumVet.com. Those who wish to apply this credit to fulfill state relicensure requirements should consult their respective state authorities regarding the applicability of this program. 1. The most common sites of SCC in dogs 5. Which statement regarding solar kera- b. large, fully keratinized cells with and cats are tosis is false? retained large nuclei. a. the reproductive and gastrointestinal a. Solar keratosis always results in wide- c. small, eosinophilic cells with multiple, tracts. spread, multiple skin lesions in dogs irregular nuclei. b. within the abdominal and thoracic cavities. and cats. d. small, anucleate cells with granular, c. the skin, oral cavity, and digits. b. The lesions of solar keratosis range eosinophilic cytoplasm and vacuoles. d. the urinary bladder and prostate gland. from an erythematous, scaly thicken- ing of the skin to shallow, crusting 8. Which statement regarding the appear- 2. Most cutaneous SCCs in cats occur lesions. ance of SCC is false? a. on the head, often involving the pinna, c. The lesions of solar keratosis occur on a. Many SCCs are ulcerative lesions. eyelids, and nasal planum. lightly haired, nonpigmented skin and b. Secondary inflammation is often pres- b. on the torso, often along the dorsal are associated with UV light exposure. ent when an SCC lesion is ulcerated. midline and at the tail base. d. With time and continued exposure to c. An inflamed SCC can always be eas- c. on the digits. UV light, solar keratosis lesions may ily differentiated from nonneoplastic d. in the perianal region. progress to SCC. inflammatory lesions by cytologic examination. 3. Which statement regarding the growth 6. Which statement regarding the develop- d. Histologic examination may be neces- and spread of SCC is true? ment of cutaneous SCC is false? sary to differentiate inflammatory a. Most tumors are well circumscribed a. Prolonged exposure to UV light, lack from neoplastic cutaneous lesions. and encapsulated, with no risk of local of skin pigment, and a sparse haircoat spread or distant metastasis. all contribute to the development of 9. Which statement regarding treatment of b. Most tumors are locally invasive, cutaneous SCC. SCC is true? and spread to local lymph nodes b. The mechanism frequently proposed a. The size of the tumor does not affect may occur. for cutaneous SCC and its association treatment decisions. c. Most tumors are accompanied by with UV light involves the tumor sup- b. Surgery is only necessary if primary paraneoplastic leukocytosis or hyper- pressor gene p53. treatment modalities fail. trophic osteopathy. c. In SCC, the p53 gene is activated c. Tumors respond rapidly and com- d. Most tumors develop rapidly, with dis- by UV light, and the protein product pletely to chemotherapy. tant metastases present upon initial signals increased cell cycling and d. RT is most commonly applied to examination. uncontrolled proliferation of neoplas- tumors of the nasal planum, nasal tic squamous cells. cavity, and oral cavity. 4. SCC in situ is d. Cells in which the p53 gene is mutated a. a large, cauliflower-like SCC, often continue replication even if DNA dam- 10. The prognosis for animals with SCC present on the digit of an affected cat. age is present, leading to mutation depends on the b. a large, intrathoracic SCC resulting accumulation and a greater chance of a. size of the tumor. from metastasis. neoplasia. b. location of the tumor. c. the scar that remains within the der- c. treatment modalities employed. mis of cats afflicted with an SCC that 7. Asynchronous nuclear and cytoplasmic d. all of the above has spontaneously resolved. maturation, which is a common cyto- d. a premalignant form of SCC in which logic finding with SCC, is typified by the dysplastic cells do not cross the a. large, anucleate cells that are fully epithelial basement membrane. keratinized. 142 Compendium: Continuing Education for Veterinarians® | March 2009 | CompendiumVet.com
- 49. MARKET SHOWCASE CLASSIFIED T SHOWC A SE M A R K E ADVERTISING MARKET SHOWCASE Northgate VETERINARIANS WANTED VETERINARIANS WANTED GLASS DOORS Veterinary Supply, the makers of CALIFORNIA – Incredible opportunity, great lifestyle. WASHINGTON – Fifteen-year-old small animal practice in Ultra Cage and Make over $125K/year—work a flexible schedule. No after- new, state-of-the-art facility seeks dedicated full- or part-time Econocage, hours, no emergencies, no night calls, no on-call respon- associate veterinarian or intern with the highest professional now offers choice sibility. Work in close proximity to LA, Palm Springs, Big ethics; a strong work ethic; and a relaxed, friendly personality. of glass door Bear, and coastal living in a fully equipped, progressive, We have an impeccable reputation for providing high-quality or rod gates. multi-doctor small animal practice that cares about you. and compassionate medicine to a large client base with high Available in We offer compensation packages with perks. APPLY NOW expectations. Email resume to petcarehospital@msn.com standard and — there’s no limit to your earning potential! Contact or fax to 425-316-3804. Visit us at www.petcarehospital.net. custom sizes. Steven Butchko, DVM: 5488 Mission Blvd., Riverside, CA 4140 Redwood Highway 92509; phone 951-686-2242; fax 951-686-7681. San Rafael, CA 94903 BUSINESS OPPORTUNITIES 1-888-DOGCAGE NEW YORK – Enthusiastic, compassionate, part-time small FAX (415) 499-5738 animal veterinarian wanted at a central New York practice lo- www.northgatevetsupply.com cated near the Finger Lakes. Our friendly, accommodating staff; full laboratory; and affluent clientele await you! Experience pre- ferred; the right new graduate considered. No after-hour emer- gencies, late nights, or holidays required. Flexible schedule. Need Techs? Salary commensurate with experience. Please send resume to Dr. T. Lovesky, PO Box 47, Tully, NY 13159; email Support Staff? randtlovesky@msn.com; or fax 315-696-8898. Take charge of your career! NORTH CAROLINA – Well-established, 24-hour, AAHA- Unique member-based organization will accredited small animal hospital in central North Carolina set you up in your own staffing company needs an emergency/critical care veterinarian and an associ- in the veterinary industry. Work in a nat- ate veterinarian. Located only hours from the mountains and ional network of like-minded colleagues coastlines, our busy, progressive, and expanding five-doctor to create wealth. We train & support practice is fully equipped and staffed by 25 highly motivated veterinarians, technicians, and lay staff. Established more than you. Huge income potential. 27 years, our hospital has an excellent client base and strong Jay Bishop: (800) 394-0005 emphasis on quality care. Work in a great practice environ- ment with an excellent opportunity for career development. Competitive salary and benefits include 401(k), profit shar- PRACTICES FOR SALE ing, CE, and insurance. Experience preferred. Send resume to Dr. Karl B. Milliren, 303 National Highway, Thomasville, NC 27360; email tvh303@cs.com; fax 336-475-0140. MARYLAND – Single-doctor small animal Fast. Easy. Inexpensive. practice, established 28 years, available for immediate sale or lease. Recently remodeled WhereTechsConnect.com TEXAS 2,000–sq. ft. freestanding facility on 1 acre in is your answer! Associate Veterinarian new town, Columbia, just 1 mile from town center Full-time position for enthusiastic individual with excellent work ethic. Busy small animal clinic — ideal location for specialty practice. located in thriving West Texas has full diagnostic Contact Gary S. Gross, DVM, and surgical capabilities, including ultrasound, Hickory Ridge Animal Hospital: EXCEPTIONAL endoscopy, and neurosurgery. All interested applicants welcome. 410-913-2338; 410-531-3107; pethospitalad@gmail.com. DISCOUNTS Call 432-332-5782. in Market Showcase VIRGINIA – Small animal practice in Shenandoah Valley TEXAS – For sale: AAHA-accredited small animal and ex- otics practice specializing in diagnostic medicine and laser now available! seeks full-time associate. Spacious, newly remodeled small animal hospital with in-house laboratory with IDEXX Vet Test surgery, established in 1982. Located in university area of Houston; excellent demographics. Grossed $860,000 in and QVC machine. Emergency clinic 20 minutes away. Great 2008 — great growth potential for 2009. Equipped with C ll t d to lock in Call today t l k i savingsi location to live, beautiful country, fishing, camping, great computer technology and in-house diagnostic equipment, outdoors. Seventy-five minutes from District of Columbia. including ultrasound and digital x-ray. Highly motivated, cer- for the entire year. Excellent compensation and benefits. Must be client-orient- tified staff; many with college degrees. Interactive, custom- ed; equine experience a plus. Contact Shenandoah Animal designed website. Business and real estate package; asking Hospital, PO Box 503, Woodstock, VA 22664; fax 540- $1,599,000 — financing available. Call 713-446-3399 or 459-4998; phone 540-459-2930, ask for Paula Cooper. email vetdoc81@hotmail.com for your appointment. Index to Advertisers For free information about products advertised in this issue, email the product names to productinfo@compendiumvet.com. Company Product Page Abbott Animal Health SevoFlo 119, 120 ASPCA Animal Poison Control Free magnet 101 (US only) Bayer Animal Health Drontal Plus 123, 124 Dristech, LLC Fovea Digital Radiography Inside back cover Fort Dodge Animal Health ProMeris Inside front cover (US only) Hill’s Pet Nutrition PetFitness VetSync Inside front cover (Canada only) Lloyd, Inc. ToxiBan 109 Nestlé Purina PetCare Case in Brief: FortiFlora 115 Northgate Veterinary Supply Glass cage doors and rod gates 143 Novartis Animal Health Interceptor 103, 104 Osteoarthritis Multimodal Case Challenge Back cover Veterinary Therapeutics Call for papers 114 Vet-Stem, Inc. Stem Cell Therapy 107 Contact Lisa Siebert to place your ad today. Vetstreet Pet Portal Service 117 Call 215-589-9457 or email lsiebert@vetlearn.com. WhereTechsConnect.com Job marketplace 143 CompendiumVet.com | March 2009 | Compendium: Continuing Education for Veterinarians® 143
- 50. CLASSIFIEDS ORDER FORM Please Place My Ad In: ® The Complete Journal for the Veterinary Health Care Team for ____________ issue(s) for ____________ issue(s) for ____________ issue(s) for ____________ issue(s) Pricing, Discounts, and Options* New Ad Placement Price per word $2.20 Available Discounts Single ad in multiple issues (e.g., one ad placed in Veterinary Forum for 2 issues). 10% off Single ad in multiple journals (e.g., one ad placed in Veterinary Forum and Compendium for one issue each). 15% off Single ad in multiple journals for multiple months (e.g., one ad placed in Veterinary Forum and Compendium for two issues each). 20% off Advertising Options ❏ Early Internet Exposure — Place your ad on VetClassifieds.com up to 30 days before your first issue release. (one-time cost) $30 ❏ Instant Internet Exposure —Your ad appears on VetClassifieds.com up to 7 weeks before your first issue release. (one-time cost) $45 ❏ Confidential Forwarding Service — Direct inquiries to our attention; we send them to you via mail, fax, or email. (one-time cost) $40 ❏ Deluxe Package — Add a box border and bold contact information. Choose from six styles (see below). $50 ❏ Premium Package — Deluxe Package plus your clinic/company logo (email as high-resolution tiff, jpeg, or eps file). $100 Deluxe/Premium Package Style Sample (circle letter) A B C D E F Payment VISA MasterCard American Express Call for details regarding check or money order payments. Credit Card Number Expiration Date ____________ / ____________ Contact Name _______________________________________________________ Contact Phone ( ) ________________________________________ Clinic/Company _____________________________________________________________________________________________________________________ Address ____________________________________________________________________________________________________________________________ City__________________________________________________________________ State _____________ Zip _______________________________________ Telephone ( ) ____________________________________________________ Fax ( )___________________________________________________ Cardholder Name ________________________________________________________________________ Billing Zip ________________________________ Authorized Signature________________________________________________________________________________________________________________ Mail or fax completed order form and your ad to: Email your ad and clinic/company information to: information Veterinary Learning Systems, Classified Advertising, VetForumClassifieds@vetlearn.com; CompendiumClassifieds@vetlearn.com; 780Township Line Road, Yardley, PA 19067 • Fax 201-231-6373 CompendiumEquineClassifieds@vetlearn.com; VetTechClassifieds@vetlearn.com *All ads are subject to a 40-word minimum charge and may be edited for grammar and style. All ads are posted on VetClassifieds.com on the first day of the issue month at no charge; all other advertising options incur an additional charge. Discounts are not applicable to first ad placement. Limit one discount per ad, barring promotional specials. All ads received after deadline will be printed in the next available issue(s). No cancellation after deadline. Include complete billing information with all orders. DO NOT mail check or money order payments with your ad; call for detailed instructions first. DO NOT email credit card information; mail or fax your payment information or use our secure Internet server at VetClassifieds.com. NEED MORE INFORMATION? Contact Liese Dixon, Classified Advertising Specialist, at 800-920-1695 (toll-free). Visit www.VetClassifieds.com to browse ads or place your order
- 51. The Future of Your Practice. The Future of Digital Radiography. Fovea is Where They Meet. GREG OWEN We created Fovea to provide the best digital FOUNDER & CEO, FOVEA radiography solutions possible. We knew that, DIGITAL RADIOGRAPHY given the right tools, doctors would be able to provide patient care on an entirely new level. As we look to the future of this technology, our industry, and our company, that sentiment rings truer than ever. The technology is here. We can help you make faster, more accurate diagnoses. We can help your business stay on the cutting edge and continue to grow. We can give you tools that will make a difference in the lives of your patients and customers. Call today and tell us your goals for the future. We can help you reach them. Call today for more information on Fovea’s affordable DR solutions. 888-368-3201 Or visit our website at www.FoveaDR.com. Copyright © 2009 Fovea Digital Radiography
- 52. C hallenge? Are you up for a RITIS MUL R TH TI A MO OSTEO DA L TM Hill’s Pet Nutrition, Inc. and Novartis Animal Health US, Inc. have teamed up in the fight against canine osteoarthritis. Current research suggests that a multimodal treatment approach to this potentially debilitating disease offers superior mobility and allows for a reduced NSAID dose to achieve sustained pain relief. M R ITIS ULTI OSTEOARTH M O DA The Challenge Is Simple: L Case Submit a detailed case study that highlights the effective Challenge TM use of a multimodal treatment approach in canine OA. The Rewards Are Huge: Three superior cases will be awarded up to $25,000 in cash prizes. And you’ll have the peace of mind that comes from knowing you’re helping dogs everywhere live better-quality lives. THRITIS AR M O UL E OST For information, case submission requirements, TIMODAL and to register, call 877.437.2679 or email Case mmcasechallenge@vetlearn.com today. Challenge TM Registration deadline: April 30, 2009 Case submission deadline: August 31, 2009 DER090042A