Gastric ulcers are caused when acid levels in the horse’s stomach rise to reach the upper stomach lining, which has little protection. This can happen any time a horse is stressed, such as when the horse is kept in a stall or being trailered. Stomach acid is absorbed by the horse's food or neutralized by his saliva. Symptoms of ulcers vary from horse to horse and can include abdominal pain, weight loss and lack of appetite. Horses fed plenty of hay and as little of concentrates as possible are less likely to develop ulcers.
If your horse is eating hay or grazing all day long, much of the stomach acid is absorbed or neutralized by the horse’s saliva. This roughage travels slowly through the horse’s digestive tract. Research done at Texas A&M pointed toward alfalfa hay or products as better at preventing ulcers than coastal Bermuda hay. Other types of grass or legume hays were not tested, nor did the tests reveal why the alfalfa hay worked better.
Even a lower-quality hay is better than no hay at all, but in some cases it is necessary to avoid an area’s hay supply because it contains too much sugar or may contain toxic plants. In these cases, hay substitutes may be considered, such as beet pulp, chopped hay (also called chaff) and alfalfa cubes or pellets.
Concentrates, or grains and commercially mixed horse feeds, cause higher acid contents and do not help absorb or neutralize acid much. Concentrates increase the hormone gastrin in the horse’s digestive tract, which causes more acid production. Horses spend much less time chewing concentrates, so there is less saliva going down to the stomach, and the feed stays in the stomach less as it is easier to digest. Most horses are given too much grain and too little hay, while concentrates came about to complement roughage, not replace it.
Supplements and Treatments
There are many supplements available for combating gastric ulcers. Some are designed to be given short-term for horses recovering from a stressful event, while others are to be given all of the time as a preventive. Long-term supplements are best for horses that are easily upset and stressed, or for horses that travel constantly, while short-term supplements can be useful for horses that are not stressed as often. Look for supplements with the National Animal Supplement Council seal, as these are usually of a better quality.
Do not use antacid-like supplements; these may cause problems absorbing minerals in the long run. If your horse does end up showing signs of ulcers again, the ulcers can be temporarily treated with the drug omeprazole until your stable management practices can overcome the problem again. Some trainers automatically dose their horses with omeprazole after a lot of stress as a way of preventing ulcers from building again.