EN
The studies on the influence of bacteria and parvovirus infection on reproductive failure in silver and blue foxes were carried out on 21 Polish farms. Parvoviral antibodies were detected in 35 out of 229 sera tested. Parvovirus infection could be the main cause of small litter size in only 6 farms An abundant growth of E. coli, Staphylococcus aureus, Streptococcus pyogenes, Proteus vulgaris and Clostridium perfringens was demonstrated in vaginal and prepucal swabs collected from animals tested. Isolated bacteria were susceptible to norfloxacin and amoxicillin. Antibiotic treatment, acording to results of in vitro tests, of all animals before reproduction and all vixens before parturition, resulted in a decreased number of „empty vixens”, abortions and neonatal deaths. Application of a proper antibiotic or elaboration of an empiric scheme of infections for foxes would eliminate reproductive losses on fox farms.