This document discusses the development of two diagnostic tools (ELISA and lateral flow device) for the detection of antibodies against ovine and bovine theileriosis. It provides background information on the genus Theileria, which are tick-transmitted protozoan parasites that infect ruminants. It reviews the taxonomy, life cycle, clinical signs, and pathogenic species of Theileria that infect small ruminants. Existing methods for diagnosis of ovine and bovine theileriosis are described. The objectives of this study are to develop a recombinant protein ELISA for detection of T. uilenbergi infection and a lateral flow device for rapid detection of T. annulata infection under field conditions.