Chronic mastitis in cows caused by Streptococcus dysgalactiae: Case report

Mastitis in dairy cows is an economically important disease because it makes up 38% of all diseases that occur in intensive cattle breeding. Mastitis affects milk production, either temporarily or permanently, depending on the course of infection and type of pathogen agent. Regular and timely therapy of mastitis based on the application antimicrobials, apart from prophylaxis, is very important for good health of breeding stock. This paper presents the case of repeated mastitis in a cow, Holstein-Friesian breed, 5 years old, which did not respond to antibiotic therapy. Milk samples from each separate quarter of the udder were collected under aseptic conditions and sent to the laboratory for further bacteriological tests, for isolation and identification of pathogens, as well as to test pathogen resistance to some antibiotics. On the basis of bacteriological examinations, there was confirmed the presence of Streptococcus dysgalactiae, which showed sensitivity to ampicillin, cloxacillin and augmentin, intermediate resistance to tetracycline and resistance to kotrimeksazol.(cotrimoxazole-proveriti)