The management and treatment of environmental streptococcal mastitis.

Environmental streptococci are responsible for at least one third of all cases of clinical mastitis, with the proportion varying widely between herds. Each dairy farmer should know the etiology of mastitis in the herd to allow for appropriate management. Control requires lowering the prevalence of infection, and includes shortening the duration of and preventing new infections. Prompt and aggressive treatment of clinical cases may achieve a high clinical and bactriologic rate of cure. Dry-cow treatment remains highly effective in eliminating infection. Prophylactic dry-cow treatment remains of substantial benefit in preventing new intramammary infections and clinical mastitis. An internal teat sealant has shown a comparable effect in uninfected cows in field studies. Management of exposure to environmental streptococci is essential and requires assessment of the risk of exposure (especially in bedding and other lying areas), reduction of teat-end contamination, and good hygienic milking practices. The key is in the quality of application of management.