Muscular sarcosporidiosis in the common European weasel, Mustela nivalis

Muscular sarcosporidiosis is reported for the first time in the common European weasel, Mustela nivalis. The morphology of the sarcocysts is described from fresh and stained histological preparations. Attempts to complete the sexual cycle of this mustelid parasite in a tawny owl, Strix aluco, are reported and the results discussed in the light of hypothetically likely sources of infection with muscular sarcosporidiosis for carnivores or omnivores, including man and other primates.