Suspected Sarcocystis infections of the bovine placenta and foetus.

Protozoan parasites resembling Sarcocystis schizonts were found in the brains of 2 bovine foetuses and the placentas of another 4. As typical of Sarcocystis, the organisms were located mainly within vascular endothelial cells, and frequently the zoites within the schizonts were arranged in a rosette or palisade fashion. Pathological changes noted were placentitis, myocarditis, pulmonary vasculitis and encephalitis. Attempts to demonstrate Toxoplasma by animal inoculation and serology were unsuccessful.