Anthrax has been confirmed as the cause of death of five calves in north central South Dakota's Corson and Dewey counties, reports the Associated Press for the Grand Forks Herald.

They're the first such cases in the state this year.

Anthrax usually appears in very wet or very dry conditions, when dormant bacteria spores in the soil are disturbed. Animals that consume the spores are exposed to the disease.

Several vaccines are available. State Veterinarian Dustin Oedekoven (OH'-dih-koh-ven) says it would be wise for ranchers to vaccinate cattle and other livestock in the area for the next several years.