Coyote as a final host for Sarcocystis species of goats, sheep, cattle, elk, bison, and moose in Montana.

Tissues (1 kg) from sheep, goats, cattle, moose, bison, or elk naturally infected with Sarcocystis species were fed to one to four Sarcocystis-free coyotes and the number of sporocysts in feces and intestines were counted. All 12 coyotes fed naturally infected tissues shed Sarcocystis in feces, with a prepatent period of 9 to 15 days. The four coyotes fed infected beef had 15, 25, 113, and 201 million sporocysts in their feces and intestines. The coyotes fed elk, moose, or bison had 2.5, 15, and 2.5 million sporocysts in their intestines, respectively. Sporocysts in feces of coyotes fed musculature of cattle, sheep, goats, and elk were structurally similar to those described previously from the feces of dogs. This is evidently the first report of the completion of life cycle of Sarcocystis species in moose and bison. Cross-transmission experiments indicated that one species of goat Sarcocystis completes its life cycle in both dog and coyote and that the ovine Sarcocystis is not transmissible to goats.