Equine choke refers to an obstruction of the horse’s esophagus and is a medical condition necessitating urgent attention. The condition most frequently occurs due to rapid feed consumption and the subsequent lodging of feed or other matter in the esophagus.

Choke can occur in horses of any age or breed. Risk factors for choke include poor teeth, feeding unsoaked food pellets or large pieces of vegetables, and growths in or deformities of the esophagus.

A veterinarian will diagnose choke based on multiple clinical symptoms, including saliva and feed discharge from the nostrils and mouth. Endoscopy is useful for observing the esophagus and any blockages in the organ.

Treatment of equine choke may require veterinary care, including flushing the esophagus and administering medications that relax the musculature of the esophageal structure. In rare cases, surgery may be necessary.

For horses with a history of choke, modifying the diet to slow down their consumption and soaking the feed can help prevent future incidences.

What is Choke in Horses?

A relatively common condition, equine choke occurs when the esophagus becomes partially or fully blocked by food or a foreign body. [1]

The esophagus is a muscular tube that enables the transfer of food from the mouth to the stomach.

Choke in horses is different than choking in humans, which occurs when something becomes lodged in the airway (trachea) and prevents normal breathing.

Horses can breathe when choke occurs because their airway is not obstructed. However, choke is still a medical emergency because it can result in life-threatening complications including pneumonia and esophageal rupture.

Choke commonly occurs when horses eat concentrated feeds (such as grains) too quickly without chewing properly. If a feed hasn’t been adequately hydrated with saliva, it can form a bolus that becomes trapped in the esophagus.

Non-food materials such as fecal matter and hairballs can also cause choke.

While choke can occur in any horse, ponies and senior horses may be more prone to the condition. [12]

Primary Choke

Primary choke results when food blocks the esophagus. Anything a horse eats can potentially become stuck in the esophagus.

Aggressive eaters and horses with poor teeth may be at increased risk of choke if they consume large amounts of feed too quickly.

Secondary Choke

Secondary choke occurs due to a structural deformity in the esophagus. It can also occur due to a neurological dysfunction that interferes with peristalsis (the transport of food) through the organ.

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Signs and Complications

The signs of choke are usually obvious, although some cases of the condition may go unnoticed. Signs of choke typically occur soon after the esophagus has become blocked.

Common signs of choke include:

  • Panicked eyes: Affected horses may exhibit an alarmed or confused look in their eyes.
  • Discharge: Saliva and feed may discharge from the nostrils and or mouth during choke.
  • Attempts to clear the throat: Horses with choke may cough, gag, and make repeated efforts to swallow.
  • Dehydration: Because horses with choke are unable to drink, horses will eventually become dehydrated if the condition is not addressed.
  • Elongating the neck: Stretching the neck to attempt to relieve the blockage in the esophagus
  • Discomfort: Showing signs of sweating or pain
  • Twitching neck muscles: Cramps and tremors in the muscle of the neck
  • Lump on the neck: A lump may be present on the left side of the horse’s neck where the blockage has occurred along the esophageal pathway
  • Opening the mouth: Yawning and opening the mouth wide
  • Drooling: Saliva and feed material may drool from the mouth as the horse cannot swallow effectively.
  • Grinding the teeth

Complications of Choke

If choke is not resolved promptly, complications can result and lead to long-term health problems.

Esophageal Rupture: A life-threatening complication of choke, esophageal rupture may result from the obstruction itself or attempts to dislodge the obstruction. If the esophagus ruptures, death may occur due to septic shock.

Aspiration Pneumonia: While experiencing choke, some horses may breathe in (aspirate) fluid or food into their trachea. If the fluid or food particles move into the lungs, an infection can occur. Signs of aspiration pneumonia typically occur within 24-48 hours of choke.

A study of 34 horses found that the duration of esophageal obstruction before admission to a veterinary clinic was significantly longer in horses that developed aspiration pneumonia compared to those that did not. [2]

Upon evaluation of 109 horses with esophageal obstruction, those with an increased respiratory rate and moderate to severe tracheal contamination had an increased risk of developing aspiration pneumonia. [3]

Esophageal Scarring: Scar tissue can develop if the esophagus becomes damaged to the extent of ulceration during an episode of choke. If enough scar tissue forms, it can reduce the internal diameter of the esophagus and increase the risk of future episodes of choke.

Risk Factors

Choke can occur in any horse, but is more likely in horses consuming certain types of dry commercial feeds and in horses with dental issues. Certain medical conditions can also increase the risk of developing equine choke.

Rapid Feed Consumption

The most common cause of equine choke is rapid feed consumption without adequate chewing. Course and dry foods can cause choke because they are more likely to lodge in the esophagus than softened and moist foods.

Dry feeds such as beet pulp, pellets, and hay cubes can swell quickly once they are chewed, causing them to lodge in the esophagus. Large pieces of carrots or apples can also occlude the esophagus.

Undeveloped or Poor Teeth

Foals with undeveloped teeth may be at risk of choke if given dry, coarse hay or straw.

Older horses with dental pain and fractured or missing teeth may be unable to properly move their jaw to chew their feed adequately, increasing their risk of choke.

Sedation

Drugs used to sedate your horse reduce the normal muscle movement within the esophagus, leading to an increased risk of choke. These medications