Submitted to: Veterinary Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 16, 2003
Publication Date: September 20, 2003
Citation: Dubey, J.P., Pimenta, A.L., Abboud, L.C., Ravasani, R.R., Mense, M. 2003. Dermatitis in a dog associated with an unidentified toxoplasma gondii-like parasite. Veterinary Parasitology 116:51-54.
Interpretive Summary: Toxoplasma gondii, Neospora caninum and Sarcocystis canis are single-celled parasites that can cause skin disease in dogs. Scientists at the Beltsville Agricultural Research Center report dermatitis in dog associated with a protozoa distinct from T. gondii, N. caninum, and S. canis. These findings will be of interest to veterinarians, parasitologists, and biologists.
Protozoal dermatitis was diagnosed in a six-year-old female Great Dane dog from Rio de Janeiro, Brazil. The dog died because of a chronic illness with an Ehrlichia-like organism. Numerous apicomplexan parasites were identified histologically in the section of dermal lesions. The protozoan reacted with Toxoplasma gondii polyclonal rabbit serum but not with Neospora caninum or Sarcocystis neurona antibodies. Ultrastructurally, the protozoa was not T. gondii because it had schizont-like structures with merozoites arranged around a prominent residual body, and the merozoites had several rhoptries with electron-dense contents; rhoptries in T. gondii tachyzoites are electron-lucent and a residual body is not found in groups of tachyzoites. This is the first report of unidentified T. gondii-like protozoa in the skin of a dog.