Puppy viruses like parvo, distemper and canine cough pose risks to puppies. Proper vaccination is important to protect puppies - they receive an initial series of vaccines starting at 6 weeks with final shots at 16 weeks. Keeping puppies isolated from other dogs until fully vaccinated helps prevent exposure. Parvo and distemper can be deadly if left untreated, requiring hospitalization. Responsible breeding and vaccination are the best ways to keep puppies healthy.