Botulism misconceptions

Misconception: Botulism is only a problem in Kentucky. I don’t live there so I don’t need to worry.

Reality: The bacteria that causes botulism, Clostridium botulinum, is found in soil across the U.S. and around the world. Although some areas, such as Kentucky and the eastern U.S., may see more cases than others it doesn’t mean that it can’t happen elsewhere. Cases have been reported from Maine to Florida to California. A number of these cases are caused not by C. botulinum spores in local soils, but by the movement of hay grown in endemic areas to lower-risk regions. Recent drought conditions have increased the movement of hay, and increased the risk for infection.

Misconception: I don’t feed my horses hay in round bales, so they can’t get botulism.

Reality: Horses eating hay from round bales is only one way botulism can be acquired. In these cases, forage poisoning occurs in adult horses that consume botulinum toxin from improperly dried, processed or stored forage, or if the forage is contaminated with dead animals, such as rodents, that consumed the toxin.

However, horses also can acquire botulism through wounds, such as puncture wounds, castration sites, or injection site abscess. As the bacteria in the wound grow, they produce toxin that is absorbed into the bloodstream, causing botulism.

Lastly, horses can acquire toxicoinfectious botulism, or shaker foal syndrome. This occurs when a foal consumes soilborne C. botulinum spores. These spores then infect the foal’s gastrointestinal tract and produce Type B toxin, which is absorbed into the foal’s system.

Misconception: I’ve never heard of equine botulism. That must mean it’s not a big deal.

Reality: Botulism is a devastating and costly disease that often results in the death of the infected horse. Since the bacterium that produces botulinum toxin is soilborne, it often manifests in botulism outbreaks, which affect multiple horses. Additionally, the cost to treat botulism is high and there is no guarantee that treatment will be effective.

Knowledge and prevention are the best ways to prevent equine botulism. Vaccination along with the ability to recognize the signs of infection in an unvaccinated horse are the horse’s best bet for survival.

Misconception: Dead rodents, birds and other wildlife swept up during the hay baling process are the main cause of botulism poisoning.

Reality: Although botulism toxin produced by C. botulinum in dead animals can cause illness, the majority of equine botulism cases are not associated with dead animals or type C toxin. More than 85% of equine botulism cases in the U.S. are associated with type B toxin, which is the main cause of forage poisoning.

Misconception: If a horse acquires botulism, human negligence was involved.

Reality: Botulism is considered a silent killer because it can often cause the death of an animal with no warning at all. Likewise, occurrences often are kept quiet because of the stigma attached to having a horse contract equine botulism.

Unfortunately, this stigma can be counterproductive. It means less talking about botulism and not increasing awareness, it makes it more difficult to spread information about the disease. The bacterium that produces botulism toxin is environmental, meaning it can be in the soil, in hay or in a myriad of other places. It can occur in a pasture where it had never been before or in a geographic area where outbreaks are rarely reported. It is not necessarily linked to negligence or to any particular human error.