Submitted to: Parassitologia
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/9/2004
Publication Date: 6/27/2004
Citation: Dubey, J.P., Ross, A.D. 2004. Clinical Toxoplasma gondii, Hammondia heydorni, and Sarcocysts sp. infections in dogs. Parassitologia. 45:141-146. Interpretive Summary: Hammondia heydorni is a single-celled parasite of livestock. Dogs are its main reservoir hosts. Scientists at the Beltsville Agricultural Research Center and the New South Wales Agriculture, Australia, report this parasite infection in dogs that were concurrently infected with toxoplasma and sarcocystis parasites. The rsults will be of interest to biologists, parasitologists and veterinarians.
Technical Abstract: Concurrent infections with coccidians Toxoplasma gondii, Sarcocystis sp., and a Hammondia heydorni-like parasite were identified in tissues of three littermate pups on a Kelpie dog breeding farm in Australia. In total, 20 pups in four litters had died following vaccination with an attenuated distemper virus vaccine. Toxoplasma gondii tachyzoites were identified immunohistochemically in tissues of two dogs. Sarcocystis sp. sporocysts were seen in the intestinal lamina propria of two dogs. Asexual and sexual stages of H. heydorni-like parasite were found in enterocytes of the small intestine of two dogs. Ultrastructural development of schizonts and gamonts of this parasite is described. None of the protozoa in these dogs reacted with antibodies to Neospora caninum. Feeding of uncooked tissue of sheep was considered to be the likely source of infection for these coccidian in dogs.