Nutritional Management of Gastric Ulcers

It's one of the most common phrases that equestrians hear and say: "My horse has ulcers." One of the most prevalent disorders in the equine community, gastric ulcer syndrome can be time-consuming and expensive to treat, so many owners and managers seek ways to prevent their horses from developing the stomach lesions in the first place. At the 2011 Alltech International Animal Health and Nutrition Industry Symposium, held May 22-25 in Lexington, Ky., Dennis H. Sigler, PhD, a professor in the department of animal science at Texas A&M University, discussed how careful dietary management can reduce the prevalence of equine gastric ulcer syndrome (EGUS) in horses.

"We don't have all the answers about EGUS, but we're finding out a lot of information," Sigler said, adding that recent studies have indicated that 93% of racehorses, 60% of other performance horses, and 56% of foals are affected by the disorder.

Ulcers can develop in both the nonglandular and glandular portions of a horse's stomach, and they are most commonly found in the area of the margo plicatus (the region that separates the glandular from nonglandular portions of the stomach). The glandular part of the stomach contains a mucosa with glands that secrete acid and pepsin, which are important aids in the early digestion of food. The glands also produce bicarbonate and mucus, which help form a protective barrier over the mucosal surface. This protects the glandular stomach from the damaging effects of acid and pepsin. The non-glandular region, however, has few defenses and is particularly susceptible to injury caused by stomach acid (i.e., ulcers).

Sigler explained that some of the risk factors that often predispose horses to EGUS include:

  • Stress;
  • High-intensity exercise;
  • High-starch diets;
  • Food deprivation;
  • Stall confinement; and
  • Transportation.

Currently, the only FDA-approved treatment option for horses that develop ulcers is omeprazole, a popular medication that is generally effective in treating ulcers. Sigler believes that there are a few downsides to the product to consider (which aren't necessarily based on peer-reviewed research):

  • The expense associated with omeprazole is high when used on a regular basis;
  • Long-term use might interrupt normal digestive progress because it creates a higher pH in the stomach; however, the effects of long-term use remain unclear; and
  • The increase in the stomach's pH might reduce the natural antimicrobial action of hydrochloric acid in stomach. ("Because of this increase in pH, the natural microbial population of the stomach and small intestine may change, therefore possibly opening the door for pathogenic (disease-causing) bacteria to increase in numbers," he suggested.)

So how can owners reduce the likelihood of their horses developing ulcers? Sigler explained that there are several nutritional management techniques that could discourage ulcers from forming.

Alfalfa Hay--Sigler described a study in which a group of Texas A&M University researchers, including Noah Cohen, VMD, MPH, PhD, Dipl. ACVIM, examined the prevalence of ulcers in exercising horses being fed either alfalfa or Bermuda hay. Signer noted that the horses were separated into two groups. One group received the alfalfa and the other the Bermuda hay for 28 days; then researchers swapped the treatment after a 21-day washout period that ensured no crossover occurred. All of the horses' ulcer scores were recorded before, during, and after the experiment (in this case, ulcers were scored on a scale of 0 to 4, with 0 being no ulcers present, and 4 being severe ulcers present).

Sigler explained that the first group of horses that consumed alfalfa (Group 1) had a reduction in their ulcer scores, while the group that consumed the Bermuda grass (Group 2) had an increase in their ulcer scores. Over the washout period, both groups saw an increase in their ulcer scores.

When the diets were switched, Group 2 (which then consumed the alfalfa) showed a reduction in their ulcer scores, and the ulcer scores of Group 1 (which then consumed Bermuda) increased. Sigler noted that all of the differences measured in the study were statistically significant.

"Results from this study indicate that horses which are at high risk for ulcers might benefit from a diet which includes alfalfa hay as a source of roughage as opposed to grass hay," Sigler explained.

Trace Minerals--Sigler also discussed a Texas A&M study in which a research team examined if there was an effect on ulcer score when exercising horses' diets were supplemented with trace minerals. The team used one group as an untreated control and provided another two groups with either organic trace minerals or regular trace minerals, in addition to either grass or alfalfa hay (all three groups received both types of hay).

The results indicated, once again, that when horses consumed alfalfa hay they had lower ulcer scores than when they ate grass hay. While the team found no statistically significant difference between the two trace mineral groups, there were trends for horses treated with organic trace minerals to have lower ulcer scores than horses that consumed normal trace minerals. Results of this second study indicate that alfalfa hay was again helpful in reducing ulcer severity scores, but there were also indications that certain organic trace minerals could be helpful, Sigler noted.

Pelleted Diets vs. Texturized Diets--Sigler explained that the most recent Texas A&M EGUS research indicated that horses that are fed a diet consisting of grass hay plus a textured feed (e.g., sweet feed) had lower ulcer scores when compared to those on grass hay plus pelleted feed.

Calcium--Interestingly, Sigler explained that researchers recently completed an additional study in which they added calcium to yearling horses' diets to evaluate if it would affect ulcer scores. There was no difference between the control group and the group receiving a high-calcium diet, indicating that additional dietary calcium supplementation had no impact on ulcers in horses.

Take-Home Message

Sigler encouraged owners and managers to take steps to prevent the development of ulcers, such as providing the horse continual access to forage, using dietary management techniques, and decreasing the horse's level of stress. Current studies indicate horses that might be at high risk for gastric ulcer syndrome could benefit from diets composed of alfalfa hay and textured concentrates.

He explained that more studies are needed to determine exactly why alfalfa works the way it does in reducing ulcer scores. Additionally, he noted that further research is needed to determine what other feed additives might reduce or improve equine gastrointestinal health.

About the Author

Erica Larson, News Editor

Erica Larson, news editor, holds a degree in journalism with an external specialty in equine science from Michigan State University in East Lansing. A Massachusetts native, she grew up in the saddle and has dabbled in a variety of disciplines including foxhunting, saddle seat, and mounted games. Currently, Erica competes in eventing with her OTTB, Dorado.

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