Equine colic is the term used for abdominal distress that horses commonly encounter. The incidence of horse colic is quite high. It is estimated that 10-11% of the horse population undergoes a bout of colic every year. This is a startling number when one considers that colic is still the condition that accounts for the most deaths in horses each year. For equine veterinarians colic is, by far, the most common cause for emergency calls and distressed horse owners. Although there have been great strides in equine medicine and surgery over the past 25 years, and the ability to treat and cure many equine colic conditions has drastically improved, there is no single answer or drug that will end all abdominal pain.
What causes equine digestive upsets, or even what are the various causes of colic (abdominal pain), can be a confusing topic for the horse owner. When discussing the causes of colic it is helpful to try and separate the anatomical and physiological conditions that may be involved in the equine colic and the trigger mechanisms that may have prompted the condition. For instance, a large colon impaction may be the anatomical and physical cause of the pain associated with your horse's colic, but lack of fresh water and resulting dehydration may have been the cause of the colic.
The equine abdomen contains approximately 100 feet of small and large intestine. Problems relating to colic may occur at any point in this vast digestive system, including the stomach, the small intestine, the cecum, the large intestine, the small intestine and the rectum. Naturally, many horse-owners consider the stomach when talking about colic, and the recent popularization of information regarding gastric ulcers has helped to reinforce this thought process. But, the stomach plays a minor role as a site of colic pathology. In fact, some retrospective studies have shown that only 3-4% of abdominal pain cases are due to pathology, such as ulcers, in the stomach. The vast majority, 64-68%, of equine colic disease states are related to the hindgut, including the large colon, small colon, cecum, and rectum. Additionally, a study of 180 performance horses published in March of 2005 showed that 97% of the horses had ulcers of either the stomach, the colon, or both, and 63% of this population had colonic ulceration. Some of the pathological causes of abdominal pain include gas accumulation and distention, feed impaction, sand impaction, vascular compromise, motility disturbances, colitis (inflammation of the colon), adhesions of tissues, displacement of a section of colon, and torsion or volvulus of a section of colon.
What causes these pathological conditions? This question, posed by many clients, is one that equine veterinarians are confronted with on a daily basis. Although in many cases it is impossible for you or your veterinarian to know the exact cause of the equine colic, in other cases an inciting cause can at least be suspected. Since a large percentage of colics are related to management, there is an advantage to knowing, or at least having a hypothesis as to what caused the abdominal pain. Theoretically, there is some item or items in the horse's management that can be identified, to help reduce the risk and or incidence of future episodes of the same type of illness.
Discussing all of the causes and management mistakes that can lead to a horse colic situation is almost impossible. Instead it is valuable to review the management practices that can positively influence and reduce the risk of colic. The following list of management strategies should help the horse owner to review his or her current management and determine if they are doing their utmost to reducing equine colic risks.