It's a fair question; why put my horse through an 18 hour fasting period and pay to have him scoped for gastric ulcers when I can buy Gastrogard and treat as if he did? Gastroscopy (passing a long tubing with camera on the end into the stomach) can be a stressful procedure due to the fasting required; however, the diagnostic clarity helps dictate length of treatment AND medication(s) used for treatment. First, it helps to understand the anatomy of the horse's stomach.
The equine stomach is made up of squamous and glandular mucosa. Glandular mucosa is in the lower half and is resistant to damage from acid produced in the stomach. The squamous portion of the stomach is the most commonly affected area, especially at the junction referred to as margo plicatus. Excess acid production is worsened by stress due to showing, traveling, sickness, or physical pain. Often times there are stressors that we don't acknowledge easily, such as an aggressive pasture mate or discomfort that is not visible to us. It is reported that 60-90% of showing horses have evidence of gastric ulceration, mostly seen in the squamous portion of the stomach. The pylorus is where feed exits the stomach and can be a site of ulceration as well. Efforts to heal pyloric ulcers are more involved.
Treatment with omeprazole (Gastrogard) daily is the only FDA approved method for gastric ulcers in horses. The omeprazole is a proton pump inhibitor, meaning that it limits the production of the typical stomach acid and allows the pH of the stomach to be higher. We know that gastric ulcers heal if pH is over 4.0 for at least 28 days. Typical pH of the acid in horses is around 2.7. Other medications such as Ranitidine (Zantac) can help with the discomfort of gastric ulcers, but it does not allow for complete healing. Alternatively, a combination of medications can be necessary in order to heal extensive ulcers in horses, including but not limited to: sucralfate and misoprostol.
So why scope? The best way to explain this is through examples:
Case #1- a 12 year old Warmblood gelding was acting dull in the stable and very agitated during tacking, especially girthing. Owner used 5 days of Gastrogard at a full tube a day and horse seemed better, so she continued on with a total of 28 days of Gastrogard and then weaned off. His agitation returned quickly after stopping the Gastrogard, so gastroscopy was performed. Numerous pyloric ulcerations were present. Additional medications including sucralfate and misoprostol were then used, and follow up gastroscopy showed full resolution of the pyloric ulcers. The horse continued to do well after being weaned off medications and management changes were in place.
Case #2- 4 year old Quarter Horse gelding that had moved from California a year ago had been acting different at the mounting block and was reluctant to move forward, which was unusual for him. Ranitidine greatly improved his attitude so he was kept on that until gastroscopy could be performed. Numerous grade 4 (bleeding, extensive) ulcers were located at the margo plicatus and the horse may have perforated if treatment had not been started immediately. Complete resolution of the squamous ulcers was observed at 56 day follow up gastroscopy, after daily Gastrogard therapy.
Case #3 - an 8 year old OTTB mare that is outwardly nervous and hard to keep weight on without breaking the bank in fat supplements. She has been acting more difficult and antsy in the cross ties during grooming and has bucked a few times under saddle recently. During gastroscopy, we don't find any evidence of gastric or pyloric ulcerations and after further diagnostics there is evidence of moderate lumbar facet osteoarthritis. Treatment of the facets resolves her clinical signs quickly.
So now you can see that gastric ulcers are really not that simple! There are a lot of variables and medications are not always straightforward. Seeing is believing, and knowing the location, type, and severity of ulcers goes a long way in helping your horse get back to being comfortable!
A note about compounded ulcer medications. Enticing as they may be from a cost standpoint, there is no substitute for FDA approved medications when it comes to gastric ulcers in horses. Random testing of omeprazole products on the market found them to contain as little as 36% and up to 135% of what was labeled on the product. Read more here. Omeprazole has to be absorbed in the small intestine to be effective; products that are not stabilized will not have a lasting effect to allow healing to fully occur. My best advice on this is the insure your horse if possible, or use preventive measures to avoid ulcers!
The best prevention is a diet with majority quality hay or forage and as minimal grain as necessary. High starch diets will lower the pH in the stomach right after eating, so all efforts should be made to prevent this pH dip if the horse is in heavy work. Purina Outlast is a great option. Using the preventive dose of omeprazole (labeled as UlcerGard) daily and starting 2 days prior to trailering or competition is also very effective. Slow feeders help to mimic horses grazing for longer periods of time throughout the day, eliminating acid build-up in the stomach.
If you have specific questions about your horse, please don't hesitate to reach out to us to see if a gastroscopy would be indicated!