Mastitis not only brings huge economic losses of dairy cow production, but also do harm to dairy industry, public health and food safety. The pathogen of cow mastitis which was caused mainly by bacterium is complex. The Safety of milk with respect to food born disease is a great concern around world this is especially true in developing countries like Ethiopia where the production of milk often takes place under unsanitary condition and consumption of raw milk which is typically produced in small dairy farm under unsatisfactory hygienic condition is a common practice