Incidence of black leg disease (gangrenous myositis) in a Hungarian dairy cow herd. Case report. [Hungarian]Original Title A sercego uszok (gangraena emphysematosa) elofordulasa egy hazai tejelo teheneszetben. Esetleiras.

摘要

The authors describe the incidence of black leg disease in a Hungarian dairy herd. The case occurred among young animals of 10-12 months of age. Five from 28 heifers died suddenly without clinical signs of illness during a three month period in the spring of 2010. The other animals (n=23) showed clinical symptoms such as depression, anorexia and lameness with swelling hock. Eleven heifers from these animals died within 24 hours after initiation of antibiotic treatment. Twelve animals were recovered but later they were culled because of subsequent muscle loss and decreased economic value. For diagnosis a complete necropsy on one heifer was performed. There was severe necrotizing haemorrhagic myositis of the markedly swollen left hind leg with diffuse subcutaneous oedema. Aerobic cultures of spleen and liver were negative but the anaerobic culture was positive for clostridial bacteria and the same Gram-positive clostridial bacteria were seen in the histopathological tissue slides. Although the diagnosis can be reached on the basis of clinical signs, necropsy and bacteriological findings but it is often difficult to differentiate from the other clostridial myositis. For this reason Clostridium chauvoei as a primer agent has been identified by the staining of lesion impression smears by specific polyclonal antiserum conjugated to fluorescein isothiocyanate.