Sarcocystis in mice inoculated with toxoplasma-like oocysts from cat feces.

Sarcocysts morphologically similar to Sarcocystis muris were observed in mice after inoculation with Toxoplasma-like oocysts found in feces of a stray cat. Cats that were fed mice infected with the oocysts shed similar oocysts in their feces. Sarcocysts were found histologically in about 50 percent of mice inoculated with 40,000 or more oocysts and examined 42 days or longer after exposure. Most inoculated mice developed low Toxoplasma dye-test antibody titers 3 to 4 weeks after exposure, but Toxoplasma antibody was usually not detectable in infected cats.