A horse continuously produces saliva and chews its food very well. This is necessary because otherwise it won't pass through that thin esophagus. Chewing well is also important for digestion, as it makes the food a smooth mass that can be digested more easily.

Function of the esophagus

After food is chewed and swallowed, it is transported by the esophagus to the stomach. Small muscles around the esophagus contract and push the food towards the stomach. This is called peristaltic movement.

Esophageal obstruction in horses

Sometimes the movement of food to the stomach gets stuck. This results in an esophageal obstruction. A horse will abruptly stop eating and often hold its head to the side, sometimes gag and stretch its neck. The horse is often restless and you may see food coming out of the mouth or nostrils. Sometimes you can even see the esophagus swelling on the neck. In some horses, the symptoms may look more like colic. It looks uncomfortable and scary, but fortunately most esophageal obstructions resolve on their own after about twenty minutes. If it lasts longer, contact your veterinarian for advice. Horses can fortunately continue to breathe during an esophageal obstruction, but it is painful. If food comes out of the nose, always call the vet, as food entering the lungs can lead to pneumonia.

Causes of esophageal obstruction

There are several reasons why a food bolus becomes stuck in the esophagus and causes an obstruction:

• Eating dry feed that should have been soaked in water, such as beet pulp, mash, and certain types of grass pellets.

• Insufficiently worked out anesthesia or sedation, causing weak muscles.

• Poor chewing, for example due to dental problems.

• Abnormalities in the esophagus or damage from previous obstructions.

• Esophageal dilation, especially in Friesian horses.

• Emotional: literally having a lump in the throat

Preventing esophageal obstruction

To prevent esophageal obstructions, it is important to have good management for your horse:

• Ensure your horse receives multiple portions of high-quality roughage per day.

• Have your horse's teeth regularly checked by an equine dentist.

• Dry feed such as beet pulp and mash is not accessible to your horse, but stored in a sealed cabinet. Only feed after it has been adequately soaked in water.

• Allow your horse to fully recover after anesthesia or sedation and prevent it from eating if it is not fully awake yet.

Esophageal dilation or relaxation

Some horses have a genetic predisposition for a relaxed or dilated esophagus. Unfortunately, this is a known condition within the Friesian breed. With esophageal dilation (megaesophagus), the esophagus is wider and more relaxed at certain points. Due to this, peristaltic movement doesn't work well: the muscles cannot propel food boluses properly towards the stomach. This results in obstruction. Horses prone to this condition often receive soaked roughage and mash, offered at chest height. It is also advisable to offer these horses multiple small portions per day.

So, be mindful of the thin esophagus!

In comparison to the rest of the horse, the esophagus is extremely narrow and can cause real problems if the horse is given the wrong food. For this reason, always feed whole carrots, as the horse is then obligated to chew. NEVER feed carrot slices, as if not chewed they can become lodged crosswise in the esophagus. Are you giving vegetables/fruit to your horse? Offer them whole so the horse takes a bite and chews it, or feed them in very small dice.