Choke

IMPORTANT NOTE

Choke in horses is not the same life-threatening condition in humans, where the term “choke” refers to the blockage of the trachea (windpipe) rather than the oesophagus. This difference means that unlike humans, horses with choke can still breathe.

What causes choke?

The most common cause is swallowing food or other material, that is too dry or course or that swells rapidly once chewed. All horses are at risk, however senior or horses with poor dentition are most susceptible along with greedy or hungry horses attempting to swallow food without chewing thoroughly.

Anything interfering with a horse’s ability to chew or swallow properly can predispose to choke including:

• Dental issues
• Tongue injury
• Sedation
• Trauma to the neck or oesophagus
• Grass sickness
• Botulism

What are the clinical signs of choke in horses?

• Discharge of saliva and feed material from the nostrils and/ or mouth.
• Difficulty swallowing
• Stretching/ arching of neck
• Can make repeated unsuccessful efforts to swallow, gag, retch as though trying to clear something from the back of the throat.
• Coughing
• Disinterested in food
• Occasionally a lump seen or felt on left side of neck
• Depression
• Distressed
• Fortunately uncommonly, the oesophagus can rupture and may lead to death due to shock and infection. 

Fortunately many cases resolve quickly and clear on their own. However, if you believe your horse has choke always call your vet immediately. The sooner treatment is applied, the sooner the condition will be resolved and secondary complications are less likely.

How is the diagnosis of choke confirmed?

Diagnosis is usually based on clinical signs. Your vet may pass a stomach tube up one nostril down into the oesophagus to confirm if there is an obstruction to the stomach. Failure of the tube to reach the stomach indicates an obstruction. This also allows the vet to determine the level at which the blockage has occurred, how solid it feels and if it can be gently encouraged to pass onwards into the stomach.

How is choke treated?

If you suspect your horse is suffering from choke take all food away as this would make the blockage worse and more difficult to clear.

Saliva, continually produced in the mouth lubricates a very mild obstruction allowing the obstruction to eventually pass to the stomach.

If a vet is needed horses with choke are often sedated. This will calm your horse, relax the oesophagus and lowers the neck, reducing the risk of the horse inhaling food and saliva. Your vet may also give a spasmolytic injection to help relax the muscles of the oesophagus. Passage of a stomach tube allows gentle flushing with warm water and lubricant to shift some or all of the obstructing material. This can take time and the process needs to be slow and gentle to avoid damage to the oesophagus.

The majority of cases respond well to the above treatment which can be performed on the yard.  Rare cases may require further investigation and treatment at a referral hospital.

Once cleared introduce all feed slowly. Feed sloppy feeds, grass or soaked forage alternatives for several days allowing any damage to the oesophagus time to heal. Consider soaking hay once its time to reintroduce this.

Severe episodes, long standing obstructions or repeated episodes can cause scarring of the oesophagus which reduces its diameter and increases the chances of the horse choking again. Anti-inflammatories may be prescribed to help control this problem.

Antibiotics may also be prescribed if aspiration pneumonia is a concern.

Possible complications of choke

Ulceration of the oesophageal lining from irritation caused by stuck material is common.

Rarely oesophageal rupture can occur due to obstruction or following attempts to dislodge it. Unfortunately this is usually fatal.

A common complication of choke is aspiration pneumonia. This occurs when the horse aspirates (breathes in) fluid and/or food material into the trachea and lungs leading to severe infection and can be fatal. Aggressive antibiotic and supportive treatment will be required. It is important for owners to monitor respiratory rate (normal <16 breaths/min) and rectal temp (normal 37.5-38.5oC) for a week following a choke episode.