Equine Colic

by

Susan Hopf


Equine colic is a catchall term for any sort of gastric upset that causes pain. Horses are prone to colic because they are incapable of reverse peristalsis (what goes in must take the long way out – no regurgitating or burping for our four-legged friends). 


There are many causes of colic; parasitic load, change of diet, change of weather, lack of water, genetic predisposition, cancer, ulcers and the most common cause of colic – your guess is as good as mine Regardless of the reason colic is something every horse owner dreads. 


The signs of colic vary from horse to horse and episode to episode. They include raising of the upper lip, turning, looking and/or kicking at the belly, head shaking, rolling, lack of appetite and restlessness that cannot be eased – all indications of discomfort and pain. You will also note an increase in pulse and respiration that indicates distress. Red flag values of these vital signs are anything above 60 for pulse and anything that looks out of the ordinary for respiration. This is a good time to mention that you should become familiar with your horse(s)’ normal values as they do vary greatly.


Depending upon the horse and the severity of the pain things may progress to a state of shock. An excellent indicator of such is the capillary refill time – lift the upper lip, press your finger on the gums for a second or two and note how long it takes the gums to turn from white back to pink. Any delay in the return of pink to the gums is indicative of shock and a red flag situation. 1-2 seconds is average but you should know before hand your horse’s normal refill time.


Another very important determination that should be made is what sort of gut sounds the animal is producing. This can be accomplished with either a stethoscope or your ear. Listen to the belly in several locations facing the front of the horse to help minimize the risk of a kick. A normal gut should have mild intermittent gurgles and rumbles. Loud and consistent gurgles similar to a freight train running through a tunnel are indicative of a gassy colic. The absence of gut sounds all together is a waving red flag and the vet should be called immediately and told of this finding. 


If you have ascertained that your horse has a gassy colic you have several choices. You can walk the horse and if the symptoms are mild even trot her on a longe line. The increased activity may help her pass this gas and allow her bowels to move whatever else may be ailing her. If, within an hour, this sort of assistance grants little or no relief or if, within your attempts to help she gets worse, it is time to call the vet. Have the following information ready: how long the horse has been exhibiting signs plus the severity and type. If you also can offer pulse and respiration, temperature if she will safely allow you to take it, gut sounds and capillary refill time your vet will have a clearer understanding of just how critical your horse may be. 


Once the vet arrives an exam will take place that includes above vital signs. A rectal exam will follow and a determination will be made as to how to proceed. A gassy colic will be treated with a smooth muscle relaxant and that may be all that is needed to allow the horse to work through the episode himself. If an impaction is found medication of the same sort will be given along with a flush of mineral oil administered through a nasal tube. As long as gut sounds are still present and the horse’s pain is managed with the medication this will be given about 12 hours to help the impaction pass. Observation of the horse at this time is critical so ensure that he remains comfortable until the follow up rectal declares him impaction-free. Any worsening of signs means another call back to the vet. 


Blood work may be suggested if you can offer no obvious reason for the colic. Infections and liver failure can create colic situations and blood work will point to these plus a whole array of abnormalities that may have contributed to the gastric upset.


The most serious consequence of a colicky episode is torsion – a twisting in various places along the bowel. This occurs due to the distention of the stomach and/or bowel and at times from a horse rolling as a reaction to the pain. It can also occur without any such activity from the horse as a result of the continued motility of the bowel itself. Surgery can correct torsion but it must take place before the circulation to the bowel is compromised. Once bowel death occurs the prognosis is not good.


The best line of defense is prevention – a good worming program, feeds that are not too coarse, full access to water and slow changes in the diet whenever they are necessary. However despite the precautions your horse may still colic at some point in his life. Know the signs and know what to do and most horses will survive to eat another day.