Surto de mastite bovina causada por Arcanobacterium pyogenes / Outbreak of bovine mastitis caused by Arcanobacterium pyogenes

An uncommon outbreak of mastitis caused by Arcanobacterium pyogenes in 26 cows is reported. The epidemiological findings, clinical signs, microbiological exams, somatic cell count, in vitro susceptibility profile of strains, efficacy of intramammary treatment and control measures were discussed. Florfenicol (96.2 percent), cefoperazona (92.3 percent), cefaloxin (84.6 percent) and ceftiofur (84.6 percent) were the most effective antimicrobials, and neomicin (27.0 percent) and enrofloxacin (17.4 percent) the least effective antimicrobials.