It always surprises me when an experienced horse person asks me how I treat “colic.” That question is akin to asking a physician how they treat a “limp.”
Equine colic is simply abdominal pain.
Signs of equine colic are what we see – a horse’s behavior when it is experiencing abdominal pain.
Like a limp, colic can be caused by any of a large number of conditions (diagnoses). The key question we (vets and horse owners) must always ask is: What is the condition (diagnosis) that is causing the colic? The answer provides the information needed to determine how it should be treated.
Examples that I hear frequently:
– Horses colic when the barometric pressure drops.
– If you keep a horse from rolling, he can’t twist his intestine.
– Putting a colicy horse in a trailer and driving around will “fix” him.
– If a colicy horse passes manure, they are getting better.
Equine gastrointestinal tract
Conditions causing colic
Colic signs may result from disturbances that occur anywhere along the gastrointestinal tract, or even from problems with other abdominal organs like the kidney or liver. Intestinal pain can even be confused with pain coming from other areas of the body (examples include muscle pain and chest pain). Examples of conditions causing colic, let’s call them CCC’s for short, can be broken down by the intestinal region that is being affected. For example, the stomach can develop ulcers or an impaction of feed material. The small intestine can be affected by something simple like a spasm, or something serious like a twist. The large colon may be affected by simple gas, blocked by a stone or strangled by a twist. Any of these regions can be affected by inflammatory disorders or bacterial infections. These are just a few of many examples of problems causing colic. As a horse owner watching a horse showing signs of colic, you truly have no idea of the condition that is causing it.
What exactly causes pain in horses experiencing colic?
Pain arises from a CCC through at least one of the following ways:
– Over-filling (distension) or muscular spasm of part of the intestine. Example: gas accumulation, spasmodic colic.
– Irritation to the inner surface of the intestine. Example: gastric ulcers, blister beetle toxicity.
– Loss of blood supply to a segment of intestine. Examples include large colon volvulus and thromboembolic colic.
Breaking the pain cycle
Of 100 horses that we notice showing signs of colic, 60-70 will recover if we simply give the horse a little time, or a shot of Banamine® (flunixin meglumine – a potent anti-inflammatory and pain reliever). But it is critical for us to understand what we are doing when we give Banamine®. We are taking away the pain. If the condition causing the colic pain happens to be minor, then it will likely resolve on its own. If the condition is more severe, we may make the horse appear improved for a time, but we are probably delaying proper diagnosis and treatment, and this could cost the horse its life.
Once a horse is in colic pain (from any condition) there is a sequence of events that tend to worsen the problem. In a healthy horse, normal movement of the gut propels food, fluid, and gas down the tract. Blockage of this normal movement from any cause leads to gas and fluid backup, stretch on the intestinal wall, and pain. Pain causes the nervous system to shut down normal intestinal movement. The shutdown of the gut leads to more gas and fluid accumulation, which leads to more stretch on the gut wall, and more pain and the cycle continues and worsens.
If this cycle is broken by appropriate treatment, including pain relief, there is a better chance of the problem resolving. This is why it is important to start treatment early. This also assumes that the condition is a “simple” cause of colic and not a mechanical obstruction. If the problem is a true mechanical obstruction like a displaced, twisted or impacted segment of intestine, it will not resolve with conservative treatment or time. Instead, it may require colic surgery or intensive medical veterinary care.
It is impossible for an observer of a horse in colic pain to distinguish between the less serious and the more serious CCC’s. More severe pain and longer lasting pain is more likely to be caused by a more serious condition, but this is not always the case.
CCC’s are common. Roughly 5 to 10% of domestic, stabled horses will experience an episode of colic in a given year.