Sarcocystosis in capercaillie (Tetrao urogallus) in Finland: description of the parasite and lesions

Acute generalized sarcocystosis was diagnosed in a capercaillie (Tetrao urogallus) from Finland. Microscopic lesions were seen in the heart, lungs, spleen, liver, and brain. Protozoa were found in all organs, especially in the lungs and spleen. Only asexual stages were observed. The parasite divided by endopolygeny. Schizonts were usually 10 microm wide and up to 55 microm long. Merozoites are 3-4 microm long and 1.5-2.0 microm wide. Sarcocysts and sexual stages are unknown. The parasite was considered to be a species of Sarcocystis with an unknown life cycle. This is the first report of acute sarcocystosis in capercaillie from Finland.