Colic Surgery

90% of colic in horses can be treated medically, and most will have a happy an uneventful outcome. Even with surgical colic, treatment has evolved over the last few years, and certain types of surgical colic have a very high success rate. Broadly, problems fall into one of three common types:

Large intestinal impaction/displacement – With these, there is no, or limited, compromise to the large intestinal mucosa. The intestine has moved out of its normal position and become kinked. These may present as low-grade, grumbling colic which is controlled by painkillers, but returns when the painkiller wears off. Alternatively, if the kink is complete, the horse’s intestine quickly fills up with gas and becomes extremely distended and causes severe, unrelenting pain. Whilst they can be spectacular and frightening, this type of colic has a success rate of over 90% with surgery.

Small intestinal obstruction – This is where the small intestine becomes twisted (torsion) and loses blood supply to some or all of its length. If discover, diagnosed and treated quickly, the intestine can sometimes be left in place, and simply untwisted. Most commonly though, the segment of dead intestine must be removed. In older horses (particularly ponies) we see a type of obstruction that is caused by a fat cancer (lipoma) that when hanging on a pedicle (stalk) wraps around the bowel (particularly the small intestine). Sometimes we just have to cut the pedicle whilst in others we have to resect the dead bowel and join the normal bowel back together.  Whilst modern surgical techniques make this a routine procedure, there are post-operative problems which make the success rate with this type of surgery be less than 70%. The first problem is that the small intestine secretes large volumes of fluid to dissolve and digest food. This fluid dams up in front of the kinked segment of intestine prior to surgery, causing it to dilate and stretch its muscular wall. This leads to post operative paralysis of the small intestine, such that the horse cannot be fed or watered until the paralysis resolves. The second problem is that the dead intestine allows passage of bacteria and toxins across the gut wall into the general circulation. This causes many systemic effects on the cardio-vascular and digestive system which can lead to laminitis (founder), kidney failure, liver failure and a host of other problems which can lead to death of the animal many days after surgery. Whilst this can occur in any age of horse, we see it most commonly in middle-aged and older horses, making them much less successful surgical candidates than younger horses.

Large intestinal torsion – This also causes part of the bowel to die, but since the large intestine contains billions of bacteria and their associated toxins, the effects on the horse are immediate and catastrophic. Many of these horses die before they reach the surgical table. The aftercare of these horses is prolonged and expensive, and even with the highest level of care, many will not survive. Thankfully they are relatively uncommon.