Gastroscopy is the process of passing a scope into the stomach of a horse to visualize the inside of the stomach and the esophagus. It is commonly done to look for gastric ulcers and other causes of recurrent colic. It is also sometimes used to aid in the resolution of a severe choke and to assess the damage to the esophagus after a choke episode.
Horses must be fasted for 24 hours prior to scoping in order to allow the stomach to empty sufficiently. This is done at the hospital in a stall with mats that has had all the feed and shavings removed from it. Access to even small amounts of feed, leaves, shavings, (or other things that hungry horses will eat) can obscure the view inside the stomach.
The horse is sedated and placed into standing stocks for the exam. The gastroscope is passed up one of the nostrils and into the pharynx, where the horse then swallows it. The scope is passed down into the stomach, which is gently inflated with air to improve visibility. After the stomach is examined, the scope is withdrawn, and the esophagus is examined as the scope comes out.
The most common finding in the stomach is gastric ulceration. The horse's stomach is divided into a glandular portion and a non-glandular portion. The glandular portion secretes mucus, which protects it from the acid in the stomach, but the non-glandular portion does not. Ulcers form along the margin of the two portions of the stomach.
A less common finding is gastric impaction of both feed and non-feed materials. These masses, known as bezoars, form in the horse's stomach and are too large to pass out into the small intestine. The treatment for gastric impactions is unusual but highly effective ĘC we give the horse Diet Coke via a stomach tube! The Diet Coke dissolves most bezoars, allowing the material to pass out of the stomach and on into the digestive tract.
When used for resolving choke (an obstruction of the esophagus), the gastroscope allows us to see what kind of material is stuck in the esophagus. Small retrieval tools can be passed through the scope to help dislodge the obstruction. Because the damage to the esophagus can be quite severe and scarring is a significant problem, gastroscopy can be used to monitor healing and identify the risk of future choke episodes.
Below are pictures taken throughthe gastroscope, a stomach with ulcers (left, black arrow) and a stomach with a bezoar.
Have questions about whether gastroscopy might help your horse? Give us a call or ask us at our next visit.