Anthrax in North Dakota

Eleven premises in southeastern North Dakota have had confirmed cases of anthrax this year in bison, cattle, and horses as of July 14. It's not uncommon to find anthrax in the state annually, but Beth Carlson, DVM, deputy state veterinarian for the North Dakota State Board of Animal Health, says there seem to be a few more cases this year. She recommends that horse and other livestock owners in the area contact their veterinarians to determine whether vaccinating their animals against anthrax would be appropriate.

Anthrax occurs naturally in some states, and horses occasionally get the disease. The anthrax agent is a resilient spore-forming bacterium called Bacillus anthracis, which lives in the ground. Livestock ingest B. anthracis when they forage close to the ground, or when they eat feed grown on infected soil. Horses seem to be more resistant to anthrax than other livestock species, such as sheep or cattle. Veterinarians have ventured to say a very  wet spring in North Dakota could have caused dormant anthrax spores to wash up into areas where vegetation is growing. There it could be ingested by animals that are foraging.

Roughly 30-35 animals have been infected with anthrax in the current outbreak. "It's a few more than we normally see--some years we only see few or none," says Carlson. "But sometimes we see an increase. Looks like this year's going to be like that." All of the cases are in Ransom and Barnes Counties. Four premises had horses, with one horse on each premises. None of the horses survived.
"I think it's been several years since they've had anthrax (in that area)," she adds. "Most of these people were not vaccinating against anthrax, or have been kind of sporadic with vaccinating. The actual pastures where these animals have died have never had it diagnosed."
She says, for the most part, North Dakota livestock owners are good about reporting anthrax cases to state officials. "Most people, when they find a case, will call us and call the lab as well," she said. "Some people hand-deliver their samples (to the North Dakota State University Diagnostic Laboratory) to get a faster diagnosis."
Generally a farm owner will have confirmation of anthrax in one animal, and any other cases that mimic the first will be assumed as anthrax and reported to animal health officials. Anthrax is a reportable livestock disease in North Dakota, and affected premises are quarantined for 30 days following vaccination of susceptible livestock on the premises. Owners are also required to burn or bury infected carcasses of animals within 36 hours. Carlson says most owners are practicing both methods of disposal.
"We don't panic when we see anthrax, it's something that we have learned to deal with," says Carlson.

About the Author

Stephanie L. Church, Editor-in-Chief

Stephanie L. Church, Editor-in-Chief, received a B.A. in Journalism and Equestrian Studies from Averett College in Danville, Virginia. A Pony Club and 4-H graduate, her background is in eventing, and she is schooling her recently retired Thoroughbred racehorse, Happy, toward a career in that discipline. She also enjoys traveling, photography, cycling, and cooking in her free time.

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