[The problems of mastitis in mares]

Based on a group of 33 mares infected with mastitis, data regarding the time of appearance, the clinical symptoms and the bacteriological causes of the disease were evaluated. The cases were distributed as follows: 27.3% before delivery, 24.2% immediately after delivery (until the third day), 12.1% during the middle and late stages of lactation, 9.1% immediately after the weaning of the foal and 27.3% outside the lactation period of non-pregnant mares. The clinical picture is described. In the majority of the cases, both halves of the udder were infected. The analysis of the bacteriological results showed that from 70 isolated germ types no less than 36 were streptococci (in 25 cases beta-haemolytic streptococci). Compared to this, E. coli (3 cases), coliform germs (6 cases) and klebsiella (2 cases) were found rather seldom. The additional examination of milk samples taken from healthy mares during the first seven days after delivery showed that 13 (= 41.9%) of the mares, or 21.0% of the milk samples (n = 62), were bacterially contaminated. Here, too, the streptococci formed the majority of the germs.