Gastric Ulceration in Adult Horses
Dr. Melissa Mazan
The goal of treatment is to decrease the level of acidity in the stomach in order to allow the horse's natural healing processes to mend the ulcers. There are several ways to achieve this goal: all of them center around addressing the situation that allowed your horse to develop gastric ulceration in the first place. The way that you and your veterinarian choose to treat gastric ulceration will usually depend on your schedule as well as your ability to change your horse's environment. H-2 blockers. These drugs block histamine, one of the factors that stimulates acid production. They reduce the signals to the acid-producing cells, so that they slow down their rate of acid production. Drugs that fall into this category include cimetidine, ranitidine, and famotidine. All of these are available as over-the-counter drugs for humans, albeit in much smaller concentrations than are suitable for a horse! Most of them must be given three times a day for them to work properly.
Most horses do require some drug therapy in order to successfully treat gastric ulcers. Drugs designed to treat gastric ulcers may decrease the amount of acid produced by the stomach, physically coat the stomach to prevent the acid from wreaking havoc or buffer the acid in the stomach.
Drugs that decrease the amount of acid produced by the stomach
Proton pump inhibitors. Proton, or hydrogen pumps, are the mechanism by which acid is actually produced by the cells. Acidity is merely a reflection of the amount of hydrogen ions, or protons that are in a fluid. If you prevent the pumps from working, then the acid level will decrease dramatically. Gastroguard® is a proton pump inhibitor that is now on the market for horses. One of the nice features of this drug is that it is only given once a day.
Drugs that block acid
The most commonly used drug that blocks acid from getting access to the stomach lining is sucralfate. Sucralfate, however, is best for helping to heal ulcers in the glandular mucosa, and most adult horses have ulcers in the squamous mucosa. For this reason, it is not suitable for use on its own in treating gastric ulcers in adult horses.
Drugs that buffer acid
Antacids are commonly used in humans, and some veterinarians advocate using them in horses. Antacids can buffer an adult horse's stomach, however, the effect lasts for less than an hour, and very large volumes (over 1/3rd of a pint) must be used.
Feeding and Environmental Changes
It is difficult to impossible to fully heal gastric ulcers using drugs alone. The most important thing we can do to heal ulcers is to recognize that horses need to live like horses! In the wild, horses do not have two, or three, or even ten meals a day – they eat small amounts of roughage all the time. If we fed horses the way they are meant to be fed, we probably wouldn't ever have to treat ulcers. The drugs may vastly improve the clinical signs, but many veterinarians report that the ulcers themselves still persist. In order to have full resolution of the gastric ulcers, it is important to give the horse as much 'down time' as possible. In the best of all possible worlds, this would mean pasture turnout for 24 hours a day. Your horse should also be given free choice hay, so that he always has something in his stomach. If possible, grain should be avoided. If your horse needs the extra calories, they can be supplemented with many small meals and the addition of high calorie vegetable oil to his food.