Round Bale Hay Feeding Alert
Evergreen Equine of Vermont
Dr Heather Hoyns
December 4, 2017
A local colleague recently saw horses in two locations affected by botulism.
The three in NH all died, the two in VT recovered with administration of antiserum and intensive nursing care.
Both sets of horses were being fed round bales that appeared to be of excellent quality.
I treated two horses for botulism last year, again being fed round bales. Both horses fortunately did well.
It only takes a tiny amount of the clostridium botulinum toxin to kill a horse.
The spores live in the soil and are very happy to grow in the environment of a round bale (or very large square bale).
Symptoms of botulism include weak tongue, tail, eyelid and muscle tone, colic, difficulty swallowing, progressive muscle weakness, recumbency and death.
Treatment is expensive and does not always work.
There is a vaccine available and recommended if you must feed round bales.
However, we do strongly discourage feeding horses hay from round bales.