Endoscopy is a powerful diagnostic tool used by our veterinarians to examine internal structures that would otherwise be inaccessible. The endoscope is a small, flexible camera that can be maneuvered by an operator. The image captured by the camera is displayed on two larger screens. We have two lengths of endoscope available at Arizona Equine – a 1 meter scope (about 3 feet) and a 3 meter scope (about 10 feet).

 

Our veterinarians routinely use endoscopy to evaluate a patient for diseases involving the nasal passages, pharynx, larynx, esophagus, stomach, small colon, uterus, urethra and bladder. Due to the size of our equine patients and the amount of intestine they have, we are unable to perform a complete colonoscopy as there are no endoscopes long enough to visualize the whole colon.

 

Common diseases diagnosed via endoscopy include: gastric ulcers (EGUS), entrapped epiglottis, ethmoid hematoma, laryngeal hemiplegia (‘roaring’), esophageal conditions/choke, guttural pouch issues, bladder stones, uterine cysts, and other upper airway issues.

 

Gastric Ulcers

The most common disease we diagnose with endoscopy is EGUS, or Equine Gastric Ulcer Syndrome. Horses have two distinct regions of the stomach: the glandular mucosa (non-squamous) and the non-glandular (squamous) mucosa. The glandular region is at the bottom of the stomach, and is responsible for the production of digestive proteins and stomach acid. The non-glandular region is at the ‘top’ of the stomach and has no secretory function. We call the area where these two regions meet the margo plicatus. Horses can develop ulcers anywhere in the stomach; however the two most common locations for ulcers to form are along the margo plicatus and around the pylorus (entrance to the small intestine). Veterinarians utilize a grading system to describe the severity of non-glandular ulcers that ranges from 0 (normal) to 4 (extensive lesions with deep ulceration/bleeding). Based on the location and severity of these ulcers, our veterinarians will create a treatment plan to best help each patient. Common medications used to treat ulcers include: omeprazole (decreases acid secretion), sucralfate (protects stomach lining) and misoprostol (decreases acid production).

The only way to definitively diagnose gastric ulceration is via endoscopy. Some clinical signs that may be observed by the owner include poor appetite or picky eating, poor body condition, diarrhea, dull hair coat, teeth grinding, behavioral changes, recurrent colic, pain while eating, and poor performance.

Horses develop non-glandular ulcers (squamous) due to increased exposure of the stomach lining to acid. Horses constantly secrete stomach acid, and it can splash up into the non-glandular stomach area during exercise. Horses fed a lot of grain also have an increased amount of acid in the stomach due to breakdown of those feeds. The development of glandular ulcers is not completely understood, but it is thought to be due to a breakdown in normal defense mechanisms that protect the glandular stomach lining from acid.

There are many current and upcoming studies regarding the treatment and prevention of EGUS. New treatment products are hitting the market quickly, and it is important to work with your veterinarian to determine which treatment is right for you and your horse.