EN
Experiments were carried out on 137 cows. Before the drying period the udders were examined twice clinically, as well as their milk was tested bacteriologically and for its somatic cell level (CMT). Mastisan PN in the MC form (which is destined for mastitis treatment during lactation) was introduced into all quarters of the udders of 89 cows. Mastisan PN-DC containing a half dose of the Mastisan PN-MC was administered in 48 cows. Control examinations were performed twice, i.e. in the first and second week after calving. It was found that both drugs were highly effective (over 98 per cent). The prophylactic efficacy was 91 and 90.3 per cent respectively. Satisfactory therapeutic effects were observed in subclinical and clinical mastitis due to streptococci and staphylococci. The studies showed that Mastisan - a new drug elaborated at the National Veterinary Research Institute - was useful in the therapy of mastitis.