Submitted to: Journal of Zoo and Wildlife Medicine
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 3, 1997
Publication Date: N/A
Interpretive Summary: Infections by the single celled parasites of the genus Sarcocystis are widespread in livestock. Certain species of Sarcocystis cause weight loss, anemia, abortion and death in livestock. The life cycle of Sarcocystis parasites involves 2 hosts - a predator definitive host, dogs, cats, and the prey (intermediate host - cattle, sheep). Scientists at the Beltsville Agricultural Research Center and University in Uppsala, Sweden report fatal sarcocystosis in capercaillies, which is a game bird. This disease was previously misdiagnosed as toxoplasmosis. The results will be of interest to veterinarians and wildlife biologists.
A non-suppurative meningoencephalitis, previously called toxoplasmosis, was found in 53 capercaillies (Tetrao urogallus L.) examined at necropsy at the National Veterinary Institute, Uppsala, Sweden, between 1966 and 1985. Pronounced meningitis and encephalitis with perivascular cuffs of mononuclear inflammatory cells as well as focal gliosis were prominent histopathological findings. Protozoan parasites were frequently seen in association with these lesions. Ultrastructurally the protozoa showed signs of endopolygeny and they had no rhoptries. Organisms from all 12 birds subjected to immunohistochemical stainings reacted positively to Sarcocystis cruzi antiserum but not to Toxoplasma gondii antiserum. The causative agent was therefor referred to the family of Sarcocystidae, and concluded to be more closely related to species of the genus Sarcocystis than to T. gondii.