Other causes of diarrhea or semiformed to watery feces in horses include grain overload, thromboembolic disease of the colon, peritonitis, antibiotic treatment, renal failure, numerous toxicoses (eg, blister beetles [cantharidin], salt poisoning, slaframine, amitraz, propylene glycol, phosphorus, selenium, nicotine, reserpine, arsenic, mercury, monensin, organophosphates, oleander, Japanese yew, castor bean, avocado, thorn apple, potatoes, heath, algae, acorn or oak, Hypericum, corn cockle, mycotoxicoses, and horse tail [scouring rush]), hyperlipidosis, and resolving impaction of the large intestine.

Last full review/revision March 2012 by Allison J. Stewart, BVSC (Hons), MS, DACVIM-LA, DACVECC; John E. Madigan, DVM, MS