02/17/2022
Over the years, I have seen about ten cases of Botulism. Nearly all of them were associated with feeding round bales of hay. (One was a stallion that was eating spoiled grain from under a fence mounted feed bowl.) I don't know many of my clients feed the large blocks of hay, but I can see how they could hold similar risks. Two bits of advice: (1) Know your hay producer and make sure that your round bales are put up and stored properly, and (2) It is highly recommended to vaccinate for Botulism if you regularly feed round bales.
In light of the recent reports of cases of botulism associated with alfalfa pasture blocks in the Ocala area, Dr. Hall and Dr. Welch of EMCO's Internal Medicine service would like to shed some light on the subject.
Clinical Botulism occurs in horses as a result of neurotoxins produced by the soil-borne, spore-forming bacterium, Clostridium botulinum. The toxin acts by blocking transmission of impulses from nerves to muscles, resulting in muscle weakness, mild colic signs, trouble with or inability to swallow, poor tongue tone, progressing to paralysis, and possibly death associated with respiratory failure.
The reported cases are likely a form of "Forage Poisoning" from ingestion of preformed toxin produced in decaying plant material, including hay, haylage, or silage; or if animal carcass remnants are present in the hay. The association with compressed block hay or round bales is due to the fact that these forms of hay are more likely to allow environmental conditions ideal for spore formation.
Botulism is a clinical diagnosis, meaning that there is no widely available test for the disease and diagnosis is made based on symptoms and risk factors. Affected horses can recover with (often times) very intense supportive care. If you believe your horse may be showing signs of botulism, you should remove the horse from the current hay or silage they are eating and contact your veterinarian immediately. You can prevent botulism by keeping your hay in a clean dry environment; not leaving hay exposed to rain, heat and humidity for prolonged times (weeks); and discarding moldy hay when you come upon it.
For more information: https://kppusa.com/2015/02/19/botulism-deadly-killer/
Please contact your veterinarian with concerns.
Photo: Google stock
