Disease Overview

Although the vast majority of colic cases are mild, colic is the number one killer of horses. There are a number of causes of colic, which simply refers to abdominal pain in horses. While colic can range in severity from mild to life-threatening, pain relief is almost always necessary. In mild cases, which are often presumed to be the result of an intestinal spasm or excessive gas in the gastrointestinal tract, analgesia is often the only treatment needed. In cases involving an intestinal twist or displacement, surgery is likely necessary. Veterinarians and horse owners must take all cases of colic or suspected colic seriously, because it can be difficult to tell mild cases from those requiring serious intervention such as surgery in early stages.

Merck Animal Health Solutions

Clinical Signs

Infection affects the central nervous system.

  • Pawing repeatedly
  • Looking back at the flank region
  • Curling the upper lip and arching the neck
  • Repeatedly raising a rear leg
  • Kicking or biting at the abdomen
  • Repeated rolling from side to side, often with grunting sounds
  • Unexpected sweating
  • Stretching out as if to urinate
  • Straining to defecate
  • Distention of the abdomen
  • Reduced or absent digestive sounds
  • Loss of appetite
  • Depression
  • Decreased number of bowel movements
  • Elevated heart rate
  • Elevated respiratory rate
  • Dilated pupils

Risk Factors

  • Parasitism
  • Dehydration
  • Poor-quality diet
  • Feeding grain as more than 50% of the diet
  • Excessive intake of rich forage
  • Cold weather
  • Lack of exercise
  • Obesity
  • Stress


“Colic: Minimizing its Incidence and Impact in your Horse,” American Association of Equine Practitioners, copyright 2021,

Earl Gaughan, “Pain Recognition and Management in Horses,” Merck Animal Health, copyright 2018,

Scott Leibsle, “Cold Weather Colic,” American Association of Equine Practitioners, 2016,

Nancy Loving, “Colic: Updates and Prevention,” American Association of Equine Practitioners, 2016,

Important Safety Information

Banamine Injectable Solution: Not for use in horses intended for food. There are no known contraindications to this drug when used as directed. Intra-arterial injection should be avoided to avoid adverse reactions. Do not use in horses showing hypersensitivity to flunixin meglumine.  The effect of Banamine Injectable Solution on pregnancy has not been determined. Concomitant use of Banamine Injectable Solution with other anti-inflammatory drugs such as NSAIDs and corticosteroids should be avoided or closely monitored. In horses, rare instances of anaphylactic-like reactions some of which have been fatal have been reported, primarily following intravenous use.

Dolorex: For use in horses only. Not for use in horses intended for food. DOLOREX, a potent analgesic, should be used with caution with other sedative or analgesic drugs as these are likely to produce additive effects. There are no well controlled studies using butorphanol in breeding horses, weanlings and foals. Therefore the drug should not be used in these groups.