A friend just lost her horse to botulism. They had relocated from Florida to Colorado last year. I don’t know too many details except that both of their horses were fed hay together (round bale? square bale?-I don’t know) and the other horse was completely unaffected. Her vet at first suspected rabies and by the time the correct diagnosis of botulism was made, it was too late to save the horse. The vet told her there was likely a tiny amount of toxin in the hay, such as that from a decaying mouse- such a tiny amount that the other horse didn’t consume any of the toxin. My friend told me it was a terrible death for her horse.
All of this has me wondering if I need to vaccinate for botulism. I did some internet research and discovered that there was an outbreak of botulism in 2008 in Florida that resulted in the death of 200+ horses. I then spoke to my vet and she told me those deaths were in south Florida (we’re in NW Florida) and they were attributed to toxin that was contained in large round bales of hay. She said she doesn’t think the horses where I board are at much risk of getting botulism. We get square bales of good grass hay year-round from the same farmer. She did say that if our horses were placed in a situation where they were eating from large round bales that she would most likely recommend the vaccine then. Otherwise, she doesn’t feel it’s really necessary for us to vaccinate here. My horses do occasionally go out to pasture for short periods of time in the winter where they eat from large round bales. I’ve been taking my horses out there for more than 15 years without incident. I could either vaccinate them or stop taking them out to that situation. Or just carry on as usual without the vaccination! The vaccine involves three shots, one month apart, followed by annual boosters so it would be a significant expense for me to vaccinate both of my horses.
I’d like to know others’ experiences, recommendations, and suggestions on this subject. I’ve never in more than 45 years of horse ownership vaccinated for botulism. But I certainly would if I were convinced there was a need to.
Here is the website of the vaccine manufacturer: http://www.neogen.com/AnimalSafety/pdf/BotvaxBrochure_2008.pdf I don’t know if there are any others who manufacture botulism vaccine.
And here are a couple of articles from The Horse.com
http://www.thehorse.com/ViewArticle.aspx?ID=13009
http://www.thehorse.com/pdf/botulism/botulism.pdf