Anthrax is a naturally occurring disease caused by the bacteria Bacillus anthracis. These bacteria are found in the soil as spores and can lie dormant for years. Anthrax is a disease primarily of plant eating animals but all warm-blooded animals are susceptible to anthrax. Cattle, horses, goats, and sheep are the most susceptible domestic livestock.
Grazing animals likely ingest anthrax spores in soil attached to the grasses or plants they eat. Pastures where plant growth is stunted due to flooding or drought require animals to graze closer to the ground. As the animal ingests more soil, it may increase their exposure to anthrax spores. Once eaten, the animal's higher body temperature triggers the spore to germinate and multiply in the animal. Anthrax is not spread from animal to animal.
Livestock infected with anthrax can die quickly, often exhibiting no signs until just before death. Approximately 260 Minnesota farms have lost livestock due to anthrax since the disease was first recorded in 1909. The areas in Minnesota at greatest risk for this disease are areas where livestock have died previously from anthrax. The most recent outbreaks have occurred in northwestern Minnesota. A vaccine is available for livestock that provides protection against anthrax infection and livestock owners are encouraged to consult their veterinarian about vaccination.
As a precaution, any livestock found dead of unknown causes in northwestern Minnesota should be treated as an anthrax suspect. Producers should contact their veterinarian immediately so blood samples can be collected from the dead animal and submitted for testing. Do not dispose of the carcass or perform an examination until a veterinarian conducts an investigation. Where anthrax is suspected, all animals should be removed from the pasture where the dead animal was found and then vaccinated. Anthrax is a reportable disease and suspect cases must be reported to the Minnesota Board of Animal Health at 651-201-6831.