Q: Our 31 year old horse was found alive, but with his intestines hanging out. He was euthanized. What may have caused this? We had put out free salt with selenium just before the injury. Could the selenium have something to do with the horse's bowels protruding?
A: I am sorry to hear about your horse. I do not think it was due to the selenium. I can think of two scenarios. I suspect his intestines were coming out of his rectum. This is called a rectal prolapse and is usually due to straining. Various things can cause straining, including parasites, small colon impactions, rectal trauma, uroliths, neurologic disease, and tumors (very possible at his age). If horses push enough of their intestines out, they lose the blood supply to the intestines and the intestines die off. There is no easy fix for this and sometimes no possible fix.
The other scenario would be intestines coming out a hole in his body wall and skin. That is almost always due to trauma (wound).
If it was a rectal prolapse, I would recommend getting manure samples from the other horses and have them checked for parasites, even if they are on a good deworming program. If it was trauma and a wound in the horse's body wall, I would recommend you check the pasture/paddock for sharp objects.
By Erin Malone, DVM, University of Minnesota