The term "colic" is very broad, encompassing any pain in a horse's gut, regardless of the cause. When diagnosing individual cases and devising treatments, however, veterinarians will use more specific language. Here's a quick look at four common colic descriptions and what they mean.
In strangulating colic, the blood supply to a portion of intestine is cut off. This can happen when a section of small or large intestine shifts and becomes entrapped in an abnormal location; when a lipoma, a mass of fatty tissue suspended on a stalk, gets wrapped around the intestine; or when a section of bowel twists upon itself, like linked sausages. The strangulated section of intestine eventually dies and the horse is typically in extreme and obvious pain with elevated heart and respiratory rates.
The blood flow to the intestine isn't compromised in nonstrangulating colics but these situations can still be serious. These include gas colics, which occur when accumulation of gas causes painful distention in the bowels, as well as enteroliths, sand accumulations and food impactions, caused when a concentrated mass of dry feed can't pass beyond a portion of the gut. These colics tend to be less painful, or the pain is transient. Horses tend to be restless, lying down and getting up frequently and staring at their sides.
Medical colics are cases that the veterinarian suspects may be treatable without surgery. These treatments may include painkilling medication and intravenous fluids. In many cases, medications and supportive care can resolve the situation quickly, but even a mild medical colic that does not improve over the course of a few hours is likely to be referred to a larger clinic.
Surgical colics are, as the name implies, those that the veterinarian suspects will require surgery to treat. Virtually all strangulating colics fall into this category as do blockages that do not resolve with medical treatment. Numerous studies have shown that the more quickly a severely colicking horse is referred to a surgical facility, the greater are his chances of survival, so don't be surprised if your veterinarian makes this decision very quickly.
This article first appeared in EQUUS issue #426.