Light Microscopic Studies of Sarcocystis spp. Infection in Cattle Slaughtered in Three Different Abattoirs in Metro Manila

Abstract

Examination of muscle tissues of carcasses of 370 imported Brahman breed Cattle slaughtered in three different abattoirs in Metro Manila revealed an infection rate of 10.8%. Three morphologically different microscopic sarcocysts were detected; the spherical and radially striated or hirsute cysts with thick cyst wall (Type1); the spherical to oval cysts exhibiting thinner cyst wall（Type2） compared to Type1; and the spindle-shaped to elongate cysts with prominent compartmentalized arrangement of zoites separated by septae. Sarcocysts morphology and their host location suggest sarcocystis hominis and Sarcocystis cruzi as the most likely etiologic species. The infections noted may either be local or imported in origin. In the absence of any documented studies on local or imported bovine sarcocystosis in the country to date，these initial findings are valuable. However, for future studies on ultrastructural analysis of the sarcocysts and the cyst wall to confirm species identification, and experimental exposure studies to determine the probable definitive host(s) of Sarcocystis species are necessary.