Colic is one of the most dreaded conditions we see in horses and one of the most common. Dr. Anthony Blikslager from North Carolina indicates in The Horse magazine that horses are more prone to digestive upset than other domestic animals because of how their digestive tract functions and how we feed them. The manner in which we feed them is the critical part as horses evolved as grazing animals free to roam on large pastures and eat a small amount of grass off and on during the day. Now we take horses and confine them and feed them twice a day and give large quantities of concentrates, both of which are contrary to their evolution. Most horses colic because of the feeding and stabling practices that we subject them to.
To decrease the chance of colic, consider feeding your horse in a manner more natural to their evolution. When at all possible, turn your horse out in pasture as it has been shown horses at pasture colic less than those kept in stalls. I know some of you do not have turnout areas and the most important thing you can do in this case is to feed a small amount of hay throughout the day, or have hay available throughout the day. Horses colic more when eating concentrates or grain because many times the grain is not absorbed in the small intestine and moves into the large intestine. Grain in the large intestine causes the bacterial population in the gut to change to digest the starch and this creates gas. In some cases, the bacteria can produce toxins and lead to enterotoxaemia. Since horses cannot get rid of the gas by burping as cattle do, the gas builds up and causes pain. If you have to feed a large quantity of grain per day, feed small amounts frequently to avoid gastrointestinal upset.