Abstract
This article presents the results of the prevalence of sarcocystis invasion of cat-tle in the Kostanay region. The selection of cattle muscles and morphological studies were carried out from January to April 2023. In total, 100 carcasses, including 75 carcasses of bulls aged 2-3 years and 25 carcasses from cows aged 7-9 years, were examined at the slaughterhouses of the city of Kostanay, where cattle for slaughter come from different districts of the Kostanay region. During visual veterinary and sanitary examination of carcasses, macrocysts were not found. Microscopy of 300 samples of muscle tissue was carried out to determine the contamination of carcasses. During the research, it was found that sarcocysts were found in the muscles of steers and cows. The localization sites, shape, size of sarcocysts and their intensity were studied. According to morphological features the cysts correspond to the description of Sarcocystis bovicanis (S.cruzi).