Sporocysts of Sarcocystis were identified in feces samples of a crab-eating fox, and were orally given to a suckling calf; after 3 months of infection, sarcocysts morphologically similar to Sarcocystis cruzi were observed in cardiac and skeletal striated muscles. The cardiac muscles of this calf were orally given to a puppy free of coccidia, that shed sporocysts in its feces.with a prepatent and patent period of 11 and 12 days after infection, respectively. To compare the morphology of the sporocysts and cysts, a second puppy was fed on bovine cardiac muscles infected naturally, and sporocysts identical to those shed by the first dog were recovered from its feces. In spite of the significant difference between sporocysts found in the mucosa of the crab-eating fox and those shed by the first and second puppies, the species observed in this study was considered to be Sarcocystis cruzi, based on size of the sporocyts, morphology of the cyst wall, and the pray-predator cycle.
Sarcocystis cruzi; sporocysts; cysts; crab-eating fox; Cerdocyon thous; dogs; cattle
