What is Choke?
Choke is a relatively common condition that occurs when food or a foreign body blocks the horse’s oesophagus, which is the tube that takes food from the back of the mouth (pharynx) to the stomach. Choke may be partial or complete and may occur high up in the oesophagus or lower down in an area of the oesophagus called the thoracic inlet.
What causes choke?
The most common cause of choke is swallowing food or other material, that is either too dry or coarse (most commonly hay or straw), or that swells rapidly once chewed (such as sugar beet) so that its passage down the oesophagus is slowed or stopped. It can occur if a greedy horse attempts to swallow hay without chewing it thoroughly or in foals which are given access to dry, coarse hay or straw. Any condition that interferes with the horse’s ability to swallow (I.e, sedation, trauma (injury) to the neck or oesophagus etc.) can predispose to choke.
What are the signs of choke in horses?
The most obvious signs are discharge of saliva and feed material from the nostrils and/or mouth, depression and apparent difficulty in swallowing. When first ‘choked’ some horses will panic, make repeated unsuccessful efforts to swallow, cough and ‘gag’ as though trying to clear something from the back of the throat. If the condition has gone unnoticed, the horse may become dehydrated and severely depressed. If the oesophagus ruptures, death may follow due to shock and infection. Fortunately, this is VERY rare. Although many cases clear on their own, if you think your horse has choke, call your veterinarian immediately. The sooner treatment is applied, the sooner the condition will resolve and second complications are less likely.
How is the diagnosis of choke confirmed?
Your veterinarian will pass a stomach tube via a nostril down into the oesophagus to confirm that something is obstructing its passage into the stomach. This examination will also determine at what level the blockage has occurred. How is choke treated?
In most cases, saliva continually produced in the mouth lubricates the offending obstruction, eventually allowing its passage to the stomach. This means that sometimes oesophageal obstructions will clear on their own. If this doesn’t occur the veterinarian can help speed up resolution by administering a sedative or a spasmolytic injection to help relax the muscles of the oesophagus. Sometimes, this is all that is required. In more serious cases, such as ones that have gone unnoticed, resolving the blockage can be more difficult and can often involve the horse being referred to a hospital for intensive care and further medical treatment.
What are the possible complications?
The most important and serious complication is oesophageal rupture either as a direct result of the obstruction or following attempts to dislodge it. Another possible complication, and unfortunately a more common one, is aspiration pneumonia. This means that while choked, the horse may aspirate (breathe in) fluid and/or food material into the trachea and lungs causing infection, that may be fatal.
Can I prevent choke?
The most important management considerations are:
- Soak dried foodstuffs thoroughly to allow them to swell before they are eaten and swallowed.
- Ask your veterinarian to provide regular routine dental care to allow the horse to chew food thoroughly and effectively before it is swallowed. Injuries to the insides of the cheeks, caused by sharp teeth, will cause discomfort and may discourage a horse from chewing food properly. Provide permanent access to clean water to encourage the horse to drink normally.
- Some horses choke on a particular feed and once this is recognized, access should obviously be avoided.