By Vet Freya Wood
Choke, or oesophageal obstruction, is an alarming condition for a horse owner but in most cases tends to look more dramatic than it is. It is important to note that the horse is still able to breathe when affected by choke as the obstruction is not of the airway but of the oesophagus, the tube carrying food from the mouth to the stomach.
Most commonly choke is due to an impaction of food material in the oesophagus. Often it presents following ingestion of hard feed, particularly if the horse is rushing to eat and not chewing food adequately, or a piece of fruit or vegetable that is either cut into the wrong shape or not chewed. It can also be of roughage or bedding material. Occasionally choke results from a horse ingesting food that should be soaked prior to feeding but has not been – either by accident or if the horse has broken into the feed room and eaten unsoaked sugar beet.
Signs of choke can be quite dramatic and begin suddenly. They can occur immediately after eating or a period of time after depending on where the food material is lodged. Horses will often cough and stretch out their necks, appear anxious, and there may be frothy or food-stained discharge from both nostrils. Sometimes a bulge can be seen on the left side of the neck but this depends on where the material is lodged.
If it is suspected that a horse has choke, firstly do not panic. Remove any food and water from the horse’s stable and keep them as relaxed as possible. If the horse has bedding in the stable that it might eat, this should also be removed or the horse put in a stable with no bedding. Many horses clear a choke unassisted within 10 minutes so monitor for this period but if it has not cleared by then a call should be made to a vet. It is important not to try and clear the choke with a hosepipe or syringing wate as this can increase the horse’s risk of aspiration pneumonia as food material is inhaled into the respiratory tract.
Treatment by the vet depends on the severity of the choke episode. In the first instance, the horse may be given sedation to reduce anxiety and to relax the horse to help the blockage pass. A muscle relaxant may also be given at this time. If this does not resolve the choke, a nasogastric tube is passed carefully and fluids used to soften the blockage. If the obstruction is unsoaked feed, then this can take a very long time as the food material must first be rehydrated before it can be made soft enough to pass down into the stomach or back out the nostrils. This process must not be rushed to prevent any further damage to the oesophagus. Once the obstruction is cleared, the horse should be offered wet feeds for the following 12 hours before resuming a normal diet.
They should be closely monitored over the following days for repeat episodes, nasal discharge, increased respiratory rate, or a high temperature in case food material has been aspirated into the lungs.
Most of the time an episode of choke is a one off, particularly if it is due to the horse eating its food too quickly, however it can be as a result of an underlying condition. The most common culprit would be dental disease, such as extreme sharp enamel points, diastemata or a fractured tooth. This would be investigated early in cases of recurrent choke. Some horses can have a stricture, or narrowing, of the oesophagus meaning food cannot pass as easily. This is diagnosed often on endoscopic examination of the oesophagus and necessitates careful management to reduce the occurrence of choke.