Etiology and epizootology of bovine mastitis (analytical review)

Mastitis is one of the most common global diseases of dairy cattle, it is detected in 5–36% animals in a herd undergoing a single examination, and the incidence reaches 68% within a year, given that some cows get reinfected more than once. The disease causes significant economic losses to dairy industry both in the Russian Federation and globally. Mastitis is an inflammation of the mammary gland that develops in response to the effects of various factors of the external and internal environment, which are classified as mechanical, physical, biological, etc. Based on the clinical symptoms, the disease has two forms: clinical and subclinical. Both the animal and its milk shall be subjected to a thorough examination for the diagnosis establishment. The final stage of the mastitis diagnosis in cows is laboratory testing. In this case, the most informative is the bacteriological method, which helps to isolate a pathogen’s pure culture, identify it and determine sensitivity to antimicrobial drugs. The latter plays a specific role in indicating the direction of further therapeutic measures, since the obtained data facilitate selection of effective antibiotics against certain pathogens. Incorrect treatment, incompliances with the prescribed therapy, as well as unnecessary use of antimicrobials can lead to the generation of multi-resistant bacteria. Due to the widespread spread of antibiotic-resistant microorganism strains, despite the large number of drugs currently used, their effectiveness is constantly decreasing. The prospects for the further use of antibiotics as therapeutics are questioned by many researchers and international organizations due to antibiotic resistance rapidly developing in many agents. Vaccination plays a significant role in infectious disease control. The use of vaccines not only reduces mastitis occurrence in cows, but also significantly improves the quality of dairy products.