Understanding choke

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Choke is frequently dismissed as a problem affecting greedy ponies who eat too much, too quickly. Until, of course, it happens to your own horse.

Choke is the equine equivalent of getting a fishbone lodged in your throat. Food gets stuck somewhere between the mouth and stomach within the gullet or oesophagus (the tube linking mouth and stomach). This should not be confused with choking up, which is an exercise-related condition where a horse completely loses his stride rhythm and is usually seen as a racehorse suddenly slowing mid-gallop.

Choking up is properly known as “dorsal displacement of the soft palate” and is totally different from choke, which is correctly called an “oesophageal obstruction”.

Signs of choke

Horses with choke are in an acutely distressed state, coughing and spluttering. Sometimes, food and saliva pour from their mouth and nose as profuse green slime. Horses cannot vomit in the same way as people, but with acute choke they retch unpleasantly. Other signs of choke include:

  • Difficulty swallowing because of the obstruction.

  • Intermittent bending and stretching of the neck in an attempt to shift the blockage.
  • Sometimes, there is a visible swelling or lump to be felt on the left side of the neck at the top of the oesophagus.

Initially, affected horses may still try to eat, even though the food passage is blocked. If the blockage does not shift, they lose their appetite and become dehydrated.

Often the signs are noticed immediately or soon after the horse has been fed. When a horse has choke, it is obvious that there is something wrong. The good news is that it usually looks worse than it is. Most cases resolve without treatment before the vet arrives.

Causes of choke

Some horses and many ponies are “stomachs on legs” and will eat whatever is put in front of them. Choke is usually caused by dry feed swelling as saliva combines with it to block the oesophagus. Inadequately soaked sugar beet is the classic cause.

As with any traffic jam, the obstruction is made worse by the further mouthfuls of food that pile up behind the wedged mass. Other substances that may also cause choke include pieces of fruit or vegetable, pieces of wood or even shavings.

An often-underestimated reason for choke is feeding a horse too soon after he has recovered from sedation or anaesthesia. So be patient and give your horses time to wake up before giving them the equine equivalent of tea and biscuits!

Another potential risk is exhausted horses, so ensure that they drink before they eat and that all feed is sloppy and easy to swallow.

If a horse has repeated bouts of choke, it is worth looking for an underlying cause.
Once feeding problems can be ruled out, it is important to consider other possible causes of recurrent choke. These include:

  • Dental difficulties, including sharp or worn teeth in older horses and loose or erupting teeth in younger horses.

  • Some kind of obstruction — usually rare — pressing on the outside of the oesophagus that prevents the smooth passage of food. One cause is neck injuries causing swelling and abscesses, such as those associated with strangles and, more unusually, tumours.
  • Other causes of difficulty in swallowing have to be considered. In some areas of the world, this includes serious conditions such as rabies, which can mimic choke.
  • Greed — there are certainly ponies in particular who just gobble their food and get it stuck, but have nothing medically wrong with them.

Diagnosis of choke

Diagnosis is usually straightforward, based on the clinical signs. Sometimes, a vet will pass a stomach tube to confirm the site of the obstruction. Occasionally, a flexible endoscope is used to enable direct observation of the obstruction itself or to check the area for damage after the obstruction has been shifted.

There is a fine balance with choke because many cases sort themselves out and do not justify veterinary attention, but the risk of complications increases significantly the longer the duration of the obstruction. The biggest risk is the horse inhaling food and saliva then developing pneumonia. Some degree of aspiration pneumonia is seen in up to 67% of cases.

Good first aid can reduce the risks:

  • Prevent the horse from eating or drinking anything further, so he is less likely to get food down the windpipe. It is best to put him in a box with no hay or water and non-edible bedding, then contact your vet for advice. By the time you have done so, the obstruction will frequently have cleared.

  • Occasionally, a lump of obstructed food can be felt on the left side of the neck; massaging this gently may help it disperse.
  • Keep the horse quiet, with his head low, to allow saliva to drain. The vet will give sedative drugs to help this happen.

If the obstruction does not shift within a few hours, you will need help from your vet.
What the vet will do depends on how long the choke has been going on and how uncomfortable the horse is. The majority of horses will need very little treatment apart from injections to relax them and allow the obstruction to pass.

If the problem persists, the vet may use more aggressive treatment to move the blockage. A stomach tube is sometimes passed up the nose into the oesophagus and fluid gently pumped through to soften and shift the blockage.

Giving the horse large amounts of fluids via an intravenous drip will help, because the choke case can become dehydrated through continually dribbling saliva and being unable to drink because of the blockage. On rare occasions a general anaesthetic is needed to shift a blockage using surgical procedures.

The prognosis for a complete recovery after one episode of choke is good. The chance of recurrence or scarring at the site of the obstruction can be reduced by withholding dry, fibrous foods for at least three days. Any associated respiratory infections will usually rapidly resolve, but may need antibiotics for a few days. Your vet will advise what is best for the individual case.

The most obvious preventative measure is to avoid dry feed if a horse has choked before. Anything that stops him bolting feed may also help.

Suggestions include:

  • Feeding the horse away from others so that he does not rush while he eats for fear that another horse will snatch his supper.

  • Try feeding a smaller amount at a higher frequency so that the horse gets the same amount of feed per day as he was previously.
  • Put an object that is too big to eat, such as a large stone, in the feed bowl, so that the horse has to search for his feed slowly.
    While choke may be distressing for both horse and owner, diagnosis and treatment is often straightforward. And, as always, prevention is better than cure.
Originally published on horseandhound.co.uk