Colic is a broad term for abdominal pain, and a horse can experience colic for many reasons, according to The Merck Veterinary Manual. Horses with colic may repeatedly kick out their front or back legs and sweat profusely. Obstruction and gas build up can cause distension of the abdomen.
The signs of abdominal pain are nonspecific and not associated with any one complaint, according to The Merck Veterinary Manual. A horse in colic-related distress may exhibit a variety of behaviors, including lying down, rolling back and forth and biting at the abdomen. Alternatively, the horse may refuse to eat, act depressed and stop defecating. However, a sick horse will not vomit, as horses are unable to vomit.