Choke in horses is a fairly common problem. However, it’s probably not what you think. While choking in humans conjures images of someone turning purple with his hands at his throat while someone else performs the Heimlich maneuver, choke in horses is something different.
Choke in humans is caused by something lodging in the trachea blocking the airway. Choke in horses is caused by something lodging in the esophagus. A choking horse can breathe, but a choking horse cannot swallow.
The primary cause of choke in horses is a lump of poorly chewed food. Horses that “bolt” their feed, meaning they eat too fast, are at risk of choke as they try to gulp down as much feed as quickly as possible. Older horses with poor dentition and the inability to properly chew their food are also at risk. Certain types of feed can also predispose a horse to choke. Pelleted feeds are the worst culprits, as these compressed pellets tend to be very dry and then expand a certain amount when exposed to moisture.
A choking horse is pretty easy to diagnose based on clinical signs. The horse is usually, and understandably, anxious, and while standing still will be tense with its neck extended, trying repeatedly to swallow. Sometimes they have the appearance of gagging. They are usually drooling and may be seen playing in the water bucket. Sometimes, feed and saliva are coming out of the nose. Usually, you cannot feel the lodged mass along their neck — heavy musculature prevents this from being palpated.
The most important thing to do with a choking horse is sedate it and let it relax. Sometimes, merely the act of drug-induced relaxation is enough to calm the spasming esophagus so that the bolus can pass. The next step is to pass a nasogastric tube. The “stomach tube,” or NG tube, is a long plastic hose that is inserted very carefully into the horse’s nostril and passed into the esophagus. With a case of choke, the tube will only go so far until it hits the obstruction. Then the fun starts.
With the tube placed, you attach a funnel to the end and start pouring water down the tube (don’t worry — with the tube in the esophagus, you aren’t going to drown the horse). When the water reaches the obstruction, it will stop. Then you empty the tube. This gradual process will begin to soften the lodged lump until finally, sometimes after an hour of this, the water will finally go all the way to the stomach and then you have a little celebration party because your poor arms are in danger of falling off from holding the funnel and hose up above your head.
After you unblock the obstruction and sternly tell the sedated horse to stop being such a pig and CHEW the food before swallowing, you’ve got some medication to give. Firstly, the horse’s throat will greatly benefit from some pain medication to relieve the inflammation that the obstruction and your tube have caused. Secondly, always always always place the horse on a round of broad-spectrum antibiotics. Choking horses are at risk of developing aspiration pneumonia, as it is so easy to accidentally inhale a bit of food or icky gooey saliva during the time when the horse cannot swallow. And no one wants to fight a case of aspiration pneumonia, because you normally lose.
Thirdly, before you hop in your truck to go home, advise the owner not to feed the horse for about 24 hours. This allows the throat some time to rest. Then they will need to slowly ease the horse back to food by first offering only the mushiest, wettest bran mash they can create. No hay and no dry feed for a few days, and then slowly introduce these back into the diet.
For prevention, if the horse is a piggy eater, try placing some large stones in the feed bucket. This forces the horse to slow down and pick around the rocks instead of just taking huge chunks of feed and gulping them down. For older horses, sometimes dental care every six months is necessary to maintain a somewhat healthy mouth. Horses prone to choking shouldn’t be fed pelleted feed.
Dr. Anna O’Brien