By: Dr. Lydia Gray

What is it?

Enteroliths are stone-like formations in the colon of the horse that can cause obstruction and colic. Usually made up of the minerals magnesium and phosphorous, they form around such strange materials as cloth, hair, gravel, metal, plastic and shavings. There is a much higher incidence of enteroliths in California and the southeast US. All breeds and genders can form enteroliths, but Arabians and mares seem to be more prone to condition.

What can be done about it?

Because the only treatment for enteroliths is surgical removal, owners of at-risk horses are encouraged to do what they can to try and prevent the stones from forming:

  • Feed more grass hay and less alfalfa hay to reduce protein and magnesium
  • Provide more turnout and less stall confinement (pasture is ideal)
  • Do not feed wheat bran which is high in phosphorous
  • Supplement with apple cider vinegar to lower the pH in the colon

What else do I need to know?

Any horse that shows abdominal pain (colic) should be examined as soon as possible by a veterinarian. Depending on the size and number of intestinal stones, where they are located in the GI tract, and how much damage has been caused, colic from enterolith can be sudden and very painful or chronic, mild and intermittent. Horses with enteroliths may also lose weight, go off feed, and appear lethargic.


SmartPak strongly encourages you to consult your veterinarian regarding specific questions about your horse's health. This information is not intended to diagnose or treat any disease, and is purely educational.