Pathological Observations of Slaughtered Cattle Infected with Sarcocystis horninis

A slaughtered cow was discovered to have many nodules in striated muscles throughout the body. Investigations showed numerous yellowish-green, rice-grain-size nodules with cheesy contents in the myocardium and in all inspected striated muscles. Histopathological examination proved the nodules to be eosinophilic granulomas. Degenerated Sarcocystis occurred at the center of each nodule. Intact sarcocysts were also found in the normal tissues around the nodules. On the basis of morphological characteristics of intact and degenerated cysts, the sarcocyst species in the cow was identified as S. hominis.