One widely accepted truth is that horses kept on good pasture rarely have troubles with colic. In my experiences I have never found anyone to question the accuracy of this "truth" when they hear, read or discuss it. Yet I also find that rarely can a typical horse owner explain why this is so.

Colic is a general term commonly used to describe many different types of pain, distress or dysfunction of the bowels of a horse, including a wide range of temporary pains to serious impaction or bindings of the intestines. This article will directly address only one type of colic. It is a serious type, often requiring emergency surgical correction, but it is one so easily avoided with just a basic understanding of some of the mechanics involved in the pasturing of horses. We will easily bring into focus just one of the reasons behind this "truth."

As we approach the topic, let’s reflect on another seemingly distant "truth" known to so many horse owners. It is widely accepted that a horse can cause a serious colic by rolling. In fact, I have heard the advice given not to permit one’s horse to roll! When I first heard this, I found it to be almost unthinkable, in fact completely unnatural. But I’ve heard it more than once now, and I believe it to be much more common than one would hope. It is worth noting–not for criticism, but for perspective–that such advice has always come from owners of stalled horses, not pastured horses. You will soon understand why this is so, and, if you pasture your horse, you will find both pride and comfort in your understanding.

The colic we are addressing is that of a "flipped gut," where the intestinal tube actually flops over on itself, creating an actual kink in the intestine. Much like a kinked garden hose which cuts off the flow of water, the horse’s kinked intestine cuts off all movement of materials through the intestine. The result is imminently deadly, unless the kink can be relieved. I have heard of very lucky horses being intentionally re-rolled by the owners and a veterinarian, and the gut correcting its own position. More often, either emergency surgery or death is likely to ensue.

Why and how can the horse intestine flip over on itself like this? Why don’t we hear of this in a human, or in a dog? The answers lie in part in what all horse owners "know," but too few respect. We all know enough of this story to avoid the associated problems if we just would, but most of us lack enough of the details to get it all in clear perspective, and so we go innocently on about our bad stalling practices without a clue of the damage we can cause.

We all know that a horse is designed to graze. Many of us know that a horse is not designed to properly assimilate grains, and certainly not as their only intake. We all know that a horse was not intended in its natural setting to catch and eat two or three square meals per day, but instead to steadily graze hour after hour.  A horse was designed to have food going through him a little bit at a time, all the time.

But many of us, for convenience, defy these things we know and confine our horses to a stall, and then, in our thinking, "humanely" feed our horses on a schedule, with a flake of hay now and then, or perhaps hay and grain later. What happens, of course, is the hungry horse’s stomach fills, digests, and again becomes "empty" between feedings. The owner of the stalled horse believes this to be acceptable, because, after all, we and all other creatures live this way. But in this belief we are going seriously wrong. Predators such as humans and dogs, not prey animals like horses, are designed to take gorge-and-digest meals. Our systems are designed to accommodate filling and emptying without serious consequence. Why it is a horse cannot safely tolerate such feeding practices is based in a simple design detail, and one of which too few horse owners know.

A human’s intestinal tract is attached to the sidewalls of the gut cavity by a relatively narrow band or "ribbon" of connecting tissue that holds the tube closely in place. The connective tissue of a horse’s tract, however, is in the form of a very wide "ribbon," which permits the intestine to move more freely within the cavity. So freely, in fact, that it can flip over on itself and cause the type of colic described above. This type of kinking is simply not going to happen in a predator because the intestine is held too closely in place. But in a rolling horse, this simple design detail can lead to sudden life-threatening "colic."

One answer to the "truth" of our first paragraph lies simply in recognizing the importance of the fact a horse was designed to steadily graze hour after hour. It all came crashing clearly into focus for me when at a seminar I heard a professional horse dietician use the words "lack of fill." The colic with which we are concerned occurs only when the intestine "lacks fill"–in other words, between those well-intentioned, scheduled square meals of stalled or dry-lotted horses. In contrast, the horse which is permitted to act out its intended role and to graze steadily on good pasture simply is never exposed to the degree of lack of fill which can allow the intestine to flip over on itself. In the design of the horse it is the intestine’s fill and not the connective tissues which hold the tract reliably in proper position. Now one can see why the advice not to permit a horse to roll will generally come from someone with a background linked to stalled horses.

It is important to note that this article has addressed only ONE answer to the stated "truth."  Pasture grazing undeniably results in greatly reduced incidences of colic, and for many more reasons than reviewed here.