Sweden reports anthrax outbreak in beef cattle herd

The south of Sweden has discovered an outbreak of anthrax in a beef cattle herd, after 27 years with no anthrax cases.

The outbreak was unusual as it occurred in winter, and in animals not exposed to meat-and-bone meal in a non-endemic country. The affected herd consisted of 90 animals, including calves and young stock.

The animals were kept in a barn on deep straw bedding and fed only roughage. Seven animals died during 10 days, with no typical previous clinical signs except fever.

The carcasses were reportedly normal in appearance, particularly as regards rigor mortis, bleeding and coagulation of the blood. Subsequently, three more animals died and anthrax was suspected at necropsy and confirmed by culture and PCR on blood samples. The isolated strain was susceptible to tetracycline, ciprofloxacin and ampicillin.

The most likely source of the infection was concluded to be contaminated roughage, but this could not be proven by laboratory analysis. The suspected feed was mixed with soil and dust and originated from fields where flooding occurred the previous year, followed by a dry summer with a very low water level in the river, allowing harvesting on soil that is unusually unexposed.