Wrapping your arms around a 2,000-pound Percheron, or even a 900-pound Arabian, might not be possible unless you are Hulk Hogan. Even at that, you might have a hard time locating your mare's belly button so you can place your hands slightly above it for compressions.
Unfortunately, even if you could do the Heimlich maneuver on your equine friend it probably would not help. That's because choke in horses is completely different than when a human chokes, at least from an anatomical perspective.
Dr. Eric Carlson, an equine intern at the University of Illinois Veterinary Teaching Hospital in Urbana explains that, "choke is an obstruction of the esophagus," not an obstruction of the windpipe when a human chokes. He goes on to note that it can be caused by several factors. "Feed impaction due to poor dentition or ravenous eating habits is the most common reason horses get choke," says Dr. Carlson. Foreign material such as apples and wood chips can also cause the problem.
While a child choking on a piece of hot dog may grasp their neck before turning blue, a horse presents differently. "Horse owners should look out for signs of excessive salivation, coughing, and food dripping from their nostrils," says Dr. Carlson.
If you suspect that your horse has choke, do not hesitate to call your veterinarian. In the meantime, Dr. Carlson recommends that you remove hay and water immediately to prevent worsening the problem. Although the animal can continue to breath, "if left untreated, horses can get aspiration pneumonia, and the material lodged in the esophagus can cause mucosal damage and necrosis," notes Dr. Carlson.
As far as what your veterinarian can do out in the field to help your horse, "the initial aim of treatment is to reduce the patient's anxiety level and allow esophageal relaxation," explains Dr. Carlson. This noninvasive method of trying to treat choke can be done with drugs that your veterinarian would commonly have in the truck.
In an ideal world, an endoscope, a flexible wire with a camera on the end, would be used to make sure that the animal is indeed choking. However, not all veterinarians will have access to a scope, and may choose to use a nasogastric tube, a flexible plastic tube that travels from the horse's nostrils to their stomach, to try and dislodge the obstructed material.
Dr. Carlson notes that, "if, after passing the nasogastric tube, the situation does not resolve, I lavage the esophagus with water." Hopefully with a combination of these treatments the obstruction will dissolve. However, if the obstruction is too great an esophagotomy can be performed. Such a procedure entails cutting into the horse's esophagus to remove the ingested material causing the problem.
To prevent choke, Dr. Carlson recommends making sure your horse has proper dental care. Also, if your horse tends to eat its food as fast as a lineman after a big game, go ahead and place a large rock in the feed pan to slow him down.
As always, contact your local veterinarian if you have questions.