ABSTRACT
This chapter presents essential information of coccidiosis in dogs. There are four species of Cystoisospora considered to be valid in dogs, C. canis, C. ohioensis, C. burrowsi, and C. neorivolta. Extraintestinal stages of C. canis, C. neorivolta, and C. burrowsi in tissues of dogs are unknown; however, biological evidence indicated that C. ohioensis invaded the spleens and mesenteric lymph nodes of dogs fed oocysts; dogs fed individual extraintestinal tissues excreted oocysts. Dog’s experimentally infected with C. burrowsi remained asymptomatic. Mice and rats were shown to be paratenic hosts based on feeding tissues to naive dogs. Coccidia are prevalent in dogs worldwide. The ingestion of food and water contaminated with oocysts is the major mode of transmission of Cystoisospora infections in dogs. Toltrazuril and ponazuril are most commonly used; medication with the compounds reduced or stopped oocyst excretion both in naturally exposed and experimentally infected dogs.
