Mastitis is a mammalian disease which is considered important due to its potential economic damages. Trueperella pyogenesis is one of the important opportunistic pathogens of the mammary glands of cattle. This bacterium can produce acute mastitis infection in dairy cattle. In fact, this bacterium has several virulence genes which contribute to its pathogenicity. Therefore, this study aimed to determine the frequency of this bacterium in the sick cattle in addition to identifying the effective virulence gene in this disease and finally investigating the antibiotic resistance of T. pyogenes
