Inverse correlation between myositis eosinophilica and number of sarcocystis cystozoits in heart of cattle

Myositis eosinophilica (ME) in cattle is characterised by grey-greenish les ions in the muscular tissue, which is a reason for condemnation. There are histological and immunological indications that Sarcocystis is involved in the pathogenesis of myositis eosinophilica. Using a digestion-technique, a quantitative analysis of Sarcocystis was performed on heart tissue of norma l carcasses (n=24) and of carcasses condemned for ME (n=10) in Belgium. The incidence of Sarcocystis was 100% in both groups. In the carcasses with my ositis eosinophilica, less cystozoits per gram heart tissue mere counted th an in normal carcasses. A possible explanation for this is the hypothesis w hich suggests that myositis eosinophilica in cattle is the result of sarcoc yst destruction by a hypersensitivity;reaction. This hypersensitivity-react ion may be the cause of the grey-greenish lesions observed in ME.