Descriptive study of botulism in an Austrian dairy herd: a case report

An outbreak of botulism was suspected at an Austrian dairy farm in June 2010. Six Simmental cows, out of a herd of 29, were affected and showed the typical signs. The affected cows included either animals suffering from sudden recumbency and reduced tongue tone or others which developed paresis, which gradually led to recumbency. Most of the affected animals died. Two cases were submitted to the Clinic for Ruminants at the University of Veterinary Medicine Vienna in order to clarify the cause of illness. The animals had reportedly been fed recently with silage possibly polluted by discarded cat carcasses spread onto the pasture used for the silage in question. The two referred cases both showed recumbency and swallowing difficulties. Both cows had to be euthanized. One of the two cows was in the late stage of pregnancy and a healthy calf could be delivered by Caesarean section. The outbreak of botulism was diagnosed clinically as well as by confirmation of Clostridium botulinum neurotoxins C and D by mouse bioassay. To the authors’ knowledge, this is the first report in which a live calf has been delivered out of a cow suffering from acute botulism.