Choke in horses occurs when the animal has an obstruction made of food stuck somewhere between the back of the mouth and the stomach within the gullet, which can be more correctly described as the oesophagus.
Signs of choke in horses
Horses with choke are typically in a very distressed state, coughing and spluttering with general signs of discomfort. Sometimes, food and saliva pour from their mouth and nose as profuse green slime. While horses cannot vomit in the same way as people do, while suffering from acute choke they will retch in an unpleasant fashion.
Other signs of choke include:
- Difficulty in swallowing
- Intermittent bending and stretching of the neck in an attempt to shift the blockage
- Occasionally there may be a visible swelling or lump that can be felt on the left side of the neck at the top of the oesophagus (pictured below)
Paradoxically, affected horses may still try to eat, even though the food passage is blocked, which is hazardous as it means food material has the potential to go the wrong way into the lungs. If the blockage does not shift, most will lose their appetite and then they run the risk of becoming dehydrated.
Often the signs are noticed 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. While a vet should be called for advice, many cases resolve without treatment before the vet arrives.
Causes of choke
The swelling of dry feed as it combines with saliva can block the oesophagus and cause choke. Inadequately soaked sugar beet is a classic cause. The initial obstruction is made worse by 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. Chokes caused by the feeding of inappropriate food stuffs by well-meaning members of the public has been increasingly seen during the coronavirus pandemic as more people explore their local countryside in the UK.
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 any drowsy horse time to return to normal alertness, so they can swallow properly, before allowing them to eat.
Another potential risk is exhausted or dehydrated horses, so ensure that they drink before they eat and that all feed is sloppy and easy to swallow if your horse is tired.
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 should be considered
- Greed — there are certainly horses who just gobble their food too quickly and get it stuck, but have nothing medically wrong with them.
Diagnosis of choke in horses
Diagnosis is usually straightforward, based on the clinical signs. Sometimes, a vet will gently 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.
The challenge with choke is that many cases sort themselves out and do not require 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. This has the potential to be serious, so if your horse has had choke monitor them closely for the next few days, including taking their temperature.
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
- 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 may give sedative drugs to help this happen.
What the vet will do depends on how long the choke has been going on and how uncomfortable the horse is and whether they are dehydrated . 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. Withholding dry, fibrous foods for at least three days can reduce the chance of recurrence or scarring at the site of the obstruction. 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.
How to prevent choke in horses?
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.
- Feeding the horse away from others so that he does not rush while he eats for fear that another horse will steal his feed
- Try feeding a smaller amount more often 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.