An Introduction to Gastric Ulcers
Although gastric ulcers and colonic ulcers are similar in the sense that they are both a thinning of the lining of the gastrointestinal tract, they are very different. They occur in different parts of the horse’s digestive tract, present differently, are diagnosed differently and in some instances, require almost opposite treatments.
Gastric ulcers, or stomach ulcers, occur in the horse’s foregut and are a result of a break or erosion in the lining of the esophagus, stomach or small intestine. Cricket Russillo, DVM, a senior associate at Virginia Equine Imaging in The Plains, Virginia, explains that stomach ulcers typically occur in either the nonglandular region, the upper portion of the stomach, or the glandular region—the lower portion of the stomach.
Clinical Signs and Diagnosis
Clinical signs of gastric ulcers can include changes in attitude, poor appetite, colic, decreased performance, decline in body condition, weight loss and lack of energy.
To diagnose stomach ulcers, veterinarians use an endoscope. In order to perform the procedure, referred to as a gastroscopy, the horse must have fasted for 12 hours, with an exception given to water. Using a fiberoptic camera, the veterinarian inserts the endoscope through the horse’s nostril, into the back of the throat, until the horse swallows it. Then the camera is directed down the esophagus until it reaches the stomach.
According to Russillo, it is vital that all areas of the stomach be looked at for any indication of ulcers, inflammation or other irritation. A complete evaluation is crucial since horses can have ulcers in multiple areas of the stomach.
In the case of a stomach ulcer, there is a grading scale from 0 to 4; 0 indicates a healthy, non-irritated stomach, whereas 4 indicates the stomach is suffering from severe ulcers and ulcerations. The maximum grade essentially, indicates a complete loss of the epithelium. Grade 4 ulcers are large, coalescing and full thickness (with complete loss of the epithelial lining of the stomach), often with associated hemorrhage. This is called Equine Gastric Ulcer Syndrome (EGUS).
Treatment and Prevention
Russillo suggests feeding a low-starch/low-sugar diet; as in excess, it causes more acid in the horse’s digestive system. Opposite from colonic ulcers, stomach ulcers, in order to heal, require that the horse be eating and digesting at all times. This means having free-choice access to pasture and hay. A popular product, the NibbleNet, a slow-feeder hay net, has been found quite effective in these cases, as it prevents the horse from getting fat but still encourages him to continuously eat. Russillo also encourages multiple grain meals throughout the day, as opposed to the conventional morning and evening feedings.
She also encourages owners to make environmental changes for their horses. This means providing as much free pasture time as possible. She explains that horses are naturally designed to eat and graze all throughout the day and because of their natural bodily function and design, they need to have something in their system to buffer their constant acid production.
According to Russillo, there is current thinking that suggests that gastric ulcers that occur in the pyloric region of the stomach may respond better to misoprostol and sucralfate, but the ulcers in the squamous portion of the stomach seem to still respond well to omeprazole. Omeprazole is a medication that inhibits the proton pump in a horse’s stomach.
Russillo says that when owners utilize omeprazole-based products, they always need to ask for FDA-approved medication. There are a myriad of omeprazole-based products on the market that claim to cure gastric ulcers. However, the FDA has issued warnings that these products are unsafe and ineffective, as they contain varying levels of omeprazole, some at sub- or excess therapeutic levels. As of now, there is only one product officially approved to cure and prevent gastric ulcers. If clinical signs haven’t resolved after diet and medications have been appropriately adjusted, owners should also consider adjusting the horse’s training program.
According to Russillo, in the case of a performance horse, although it may not be practical, removing a horse completely from his training program may be necessary in order to give the body time to rest and heal.
explains that this diet change is temporary. Any change in diet has the potential to cause colic, but in hindgut ulcers, this change is designed to decrease colic, one of the clinical signs associated with the condition. Therefore, by reducing the bulk in the diet, the colic episodes should actually resolve. However, if colic signs continue, then having the horse evaluated by a veterinarian is indicated and it might be that the dietary change needs to be more gradual and hay could be added back to the diet.
Andrews suggests the complete pellet diet for three months in order to treat colonic ulcers. Two complete pellet grains include an equine-senior and equineadult grain, which are alfalfa hay based. Essentially, a complete pellet is grain and forage wrapped in one feed source. It is designed to totally replace hay and forage in the horse’s diet and label directions should be followed carefully so that the horse is fed the right amount.
Andrews also tends to prescribe corn oil or flaxseed oil. This coats the intestine and supplies omega fatty acids, which are anti-inflammatories for the large intestine. Typically, he suggests one cup of corn oil two times a day mixed with the senior or equine adult feed. The oil, he says, must be slowly introduced. If the horse is given too much at once, there is a chance the horse will refuse his grain.
Andrews also suggests twice-daily doses of psyllium, which is similar to Metamucil for humans. This component coats the intestine and has anti-inflammatory properties. He mentions other products that contain psyllium along with prebiotics and probiotics. It also acts as a laxative; Andrews has found that this laxative tends to lubricate the hindgut and help move feed through the colon and helps the digestive system heal.
In addition to nutritional components and changes, Andrews suggests that owners take their horses off any and all nonsteroidal anti-inflammatories (NSAIDs), such as phenylbutazone (bute) and Banamine. He recognizes that, in some cases, older horses who suffer from chronic arthritis may need these medications on a prescribed maintenance dose. His warning, however, is that these medications tend to exacerbate hindgut ulcers or may even cause the condition in the first place.
After removing these medications, he typically prescribes sucralfate. This is a pharmaceutical coating agent, approved for treating ulcers in humans. This product is not approved for horses, so he uses the human formula when administering. He advises owners to avoid compounded products, which he admits, is hard to do. This is because compounded products are not approved by the U.S. Food and Drug Administration (FDA) and the drug concentration of the compound is not verified or checked. Andrews typically uses human drugs (when an FDA-approved product is not available for horses) to treat horses with this condition because these medications are required to undergo a very rigorous FDA approval process.
Essentially, Russillo says that prevention comes down to attempting to understand potential triggers and managing the horse’s lifestyle. In the case of the performance horse, these animals tend to live a very fast-paced, high-stress lifestyle. Although we can’t always eliminate stressors, we can try to balance them as best we can. It is the owner’s responsibility to manage stress levels and provide the best maintenance routine and, when needed, the best treatment and preventive measures.
Banamine and bute can cause or exacerbate hindgut ulcers.