We use Bute (phenylbutazone) a lot in horses, and it is a great drug for pain relief – but it does have some side effects that we need to be aware of. One of these is right dorsal colitis (RDC).
The right dorsal colon is the last segment of the large intestine, and it is only this segment of the large colon that is affected by Bute.
Why this region of the large intestine? That is a question that has baffled vets for a long time, but recent research is pulling together some pieces of the puzzle and are finding that this segment of the large intestine uses unique secretions to protect the lining of the intestine from the volatile fatty acids that are produced in the large intestine.
Bute can interfere with this protective secretion, and this can result in severe ulceration and subsequent protein loss and diarrhea which can be fatal.
So, Bute does have some downsides and should only be used under veterinary guidance. When your horse is on Bute pay attention to your horse’s manure and if they produce less than 10 piles a day or if it’s starting to get like a cow-pat consistency, give us a call.