PubMed1983
In cases of summer mastitis, several other bacteria, particularly anaerobes, are isolated in addition to C. pyogenes. The fly Hydrotaea irritants which also causes 'broken heads' in sheep and is therefore referred to as the 'sheep head fly', is universally regarded as the most important vector of summer mastitis. The annual losses caused by summer mastitis are substantial. The incidence of summer mastitis varies annually and monthly. Summer mastitis is particularly observed on sandy soil, less often on peat and hardly ever on clay. This is in accordance with the habitats of Hydrotaea irritans. Several measures to prevent summer mastitis are available to farmers. When fly repellents or agents protecting the teat openings are used, fair results are obtained. Synthetic pyrethroids would appear to offer better prospects, however, because of their long-acting character. Results obtained using C. pyogenes vaccines are disappointing. Long-acting antibiotics offer good prospects in yearlings in the 1-2 year range. Findings reported in the literature show that treatment of dry cows during the dry period, repeated twice at an interval of from three to four weeks, offers the most promising prospects. In view of the small teat openings of calves, fly repellents or agents protecting the teat openings will be most successful.