[Specific prophylaxis of gangrenous mastitis in sheep]

Staphylococci were isolated from the udder of dead sheep and sheep that were emergency-slaughtered because of a gangrenous mastitis infection. The organisms proved to be hemolytic and mannite- and catalase-positive, and were referred to various phage types, being most frequently lysed by phages 78 and 42E. Toxin production depended on the quality of the medium used, the amount of atmospheric carbon dioxide, the period of incubation, and the individual strain qualities. Strains of high hemolysin production were used to prepare a vaccine which was applied to sheep both experimentally and in the conditions of the practice at the time of active lactation. Following treatment of the vaccinated animals parallel to a number of controls with one and the same challenging agent morbidity with the first group ran as high as 25 per cent with no death cases, while with the second group it was 100 per cent, and mortality with the latter was 50 per cent. Immunity with the use of the vaccine lasted but four months, therefore, revaccination was needed by the end of this period.