[Etiological study of mastitis in cows].

The rapid mastitis test was employed to study a total of 13 880 cows on 40 farms. Positive for mastitis proved 2384 udder quarters. Clinically manifested mastitis was established in 3.23 per cent of the cases, subclinical mastitis - in 58.14 per cent, carrier status - in 12.55 per cent, secretion disturbances - in 22.58 per cent, and normal proved 3.84 per cent. In the mastitis-positive cases pathogenic streptococci were isolated in 57.14 per cent of the quarters, staphylococci - in 20.77 per cent, Corynebacteria - in 9.09 per cent, and other bacteria - in 5.19 per cent. In the cases with subclinical mastitis staphylococci accounted for 40.93 per cent, streptococci - for 38.7 per cent, Corynebacteria - for 14.22 per cent, and other organisms - for 6.0 per cent. Most frequently encountered were the carriers of staphylococci - 46.8 per cent, followed by those of Corynebacteria - 26.4 per cent, and of streptococci - 20.73 per cent.