According to a study conducted among horse owners, gastric ulcers are one of the most common reasons for changing a horse’s diet. Dietary changes for horses suffering from ulcers may include adding certain feed ingredients, increasing the forage ration, reducing grain, and adding various complementary feeds that support a healthy digestive tract. Nature offers many ingredients suitable for a horse’s diet that may support gastrointestinal wellbeing, including the healing of ulcers. Below are some of the best-known feed ingredients and research related to treating equine gastric ulcers.
Gastric ulcers are often treated with antacids. Antacids are medicines that neutralize excessive stomach acidity. They mask the effects of ulcers and help them heal, but with long-term use they work against the natural physiology of equine digestion (24,25). A horse needs stomach acids, and they should not be removed long-term. Sometimes, when acid-suppressing medication is stopped, the body may respond with acid overproduction, which can predispose the horse to new ulcers.
Ulcers can occur throughout the horse’s digestive tract, but most commonly they occur in the stomach’s upper squamous (epithelial) region, because that area is most exposed to stomach acids and lacks the defense mechanisms present elsewhere.
Different supplements can work in different ways and may be useful for prevention and for follow-up care after medication. This article does not cover pectin–lecithin supplementation, which has its own article due to the breadth of research findings.
YEASTS
Yeasts are single-celled organisms that naturally live in the horse’s digestive tract. The yeasts most commonly used in horse feeds and supplements belong to the genus Saccharomyces, which includes several different species. Saccharomyces cerevisiae and Saccharomyces boulardii are two of the most researched yeast species, with a long list of documented benefits for immune function and gastrointestinal wellbeing. Yeasts have a probiotic effect. They support hindgut function by promoting fiber digestion, stabilizing intestinal pH, and improving nutrient absorption. Research shows that yeasts have many digestive and wellbeing benefits for horses. Reduced ulcer risk may be one of them, but more research is still needed.
In one study, horses were fed a high-starch diet that lowers intestinal pH. In the study, pH was deliberately lowered because acidity is a known risk factor for ulcers (1). In the study, yeast supplementation stabilized intestinal pH by reducing acidity, which suggests potential benefits in reducing colonic ulcers.
SLIPPERY ELM
According to a study (3), slippery elm bark soothes irritation in the digestive tract and supports the healing of existing ulcers. Slippery elm has a high mucilage content as well as abundant calcium, flavonoids, and vitamins (2). The benefits highlighted in the study are based on the fact that its soluble fiber content slows gastric emptying and keeps the stomach fuller for longer. The mucilage has anti-inflammatory properties that support the mucosal barrier function. In addition, it acts as a prebiotic and supports the growth of beneficial probiotic microorganisms in the digestive tract.
In a human study (3), slippery elm led to improved symptoms based on self-assessment among those with gastric irritation. An observational study in horses (21) showed significant benefits of slippery elm mucilage in treating ulcers. Four days of slippery elm treatment in 198 horses with ulcer-related colic symptoms led to improvement in 85% of horses. In the same study, 23 horses with gastric ulcers recovered using slippery elm supplementation. The results were observed without other concurrent treatments. The findings therefore suggest that the mucilage produced by slippery elm bark improves the body’s own mucosal protection and reduces gastric irritation.
MARSHMALLOW
Marshmallow root (Althea officinalis) is often used to relieve irritation and inflammation of the respiratory tract and to soothe the digestive tract. Marshmallow has also been used to support digestion. Marshmallow roots contain abundant polysaccharides that form mucilage, as well as flavonoids that support healthy cells. Polysaccharides bind to mucous membranes to calm irritated cells, and antioxidant and antihistamine effects may support the growth of healthy cells.
According to studies, marshmallow may help reduce inflammation and oxidative stress in the gastrointestinal tract and support tissue healing (5).
Marshmallow has not been widely studied in horses, but feeding rats marshmallow root for 14 days before experimentally disturbing the gastric environment reduced both the number and severity of gastric ulcers. In addition, oxidative stress and the release of inflammatory histamine decreased significantly (4). An in vitro study showed that marshmallow may support healthy intestinal cells by forming a protective layer, suggesting that marshmallow may help tissues heal under this protective layer.
MEADOWSWEET
Meadowsweet (Filipendula ulmaria) is a natural source of salicylic acid, i.e., the basis of aspirin’s active ingredient. Aspirin is commonly used in medicine to relieve fever, inflammation, and pain. Meadowsweet is often given to horses with arthritis or digestive issues such as hyperacidity, gastric ulcers, or other digestive disturbances. In animal studies, meadowsweet appears to protect against gastric ulcers (6), (7). It is often included in complementary feeds designed to support gut health to relieve pain and irritation. Meadowsweet’s tannins appear to have properties that reduce irritation of the gastric mucosa and the intestine. Salicylate has anti-inflammatory and pain-relieving effects. More research in horses is still needed to obtain reliable results.
ZINC
Zinc is an essential trace mineral for horses and has many functions related to overall wellbeing. Zinc participates in protein synthesis and immune function and has antioxidant properties. It is especially important for wound healing and may also be beneficial in preventing gastric ulcers. Zinc has a cytoprotective effect, meaning it helps stimulate mucus production and improve blood circulation to the intestinal mucosa (8). Zinc is believed to enhance mucosal protection in the gastrointestinal tract, support circulation in gastrointestinal mucosa, and promote tissue repair (9). Zinc is an essential mineral required in the horse’s diet, and supplementation may help reduce ulcers.
Zinc sulfate has been used in humans to treat gastric ulcers for many years (11, 12, 13). In rat studies, zinc showed benefits in reducing ulcer development and severity. Rats with zinc deficiency in their diet had poorer ulcer healing than those with adequate zinc intake (10).
In one equine study, feed deprivation was used to induce ulcers. Methionine is an essential amino acid often deficient in equine diets. In the study, 32 horses’ ulcers were treated with omeprazole, after which a zinc–methionine supplement was given for 49 days. Severity decreased with zinc–methionine supplementation, suggesting potential to reduce ulcer recurrence. However, the study lacked a control group, so comparisons between test groups are not possible. The study nonetheless provides preliminary indications that zinc may benefit ulcer healing.
SEA BUCKTHORN
Sea buckthorn berries (Hippophae rhamnoides) have shown promising effects in humans in reducing gastric ulcers. Sea buckthorn berries contain vitamins and minerals used for wound healing and tissue repair (15). They also contain amino acids, the building blocks of proteins. Sea buckthorn contains high levels of vitamins C and E, which have antioxidant and tissue-supporting effects. Procyanidin in sea buckthorn may promote healing and repair of mucosal cells by increasing growth factors. Sea buckthorn amino acids may also support protein synthesis and aid tissue repair.
In a rat study, sea buckthorn berry extract appeared to both prevent and treat ulcers caused by high concentrations of acetic acid (16). Although preliminary rodent results are promising, evidence in horses remains limited. Equine studies have yielded mixed results, and more research is needed (17), (18).
LICORICE ROOT
Licorice root (Glycyrrhiza glabra) is one of the oldest herbal remedies known to humans. It has traditionally been used to treat and relieve various digestive issues, including heartburn and reflux. Licorice root contains saponins—bitter-tasting plant glycosides with bioactive effects in the body. Saponins may improve the integrity of the intestinal mucosal barrier. Licorice may influence ulcers through several mechanisms: stimulating mucus production in mucous membranes, inhibiting pro-inflammatory mediators such as prostaglandin E2, and reducing the breakdown of anti-inflammatory mediators. Licorice extract is often used in humans to reduce gastric irritation. In a human study, patients reported significant symptom reduction when given licorice extract. On a self-assessment scale, licorice was more effective than commonly used antacids in reducing irritation (19,20). In rodents, licorice appears to be effective both in preventing and treating ulcers. In rat trials, licorice extract has anti-inflammatory effects similar to conventional medication (22, 23). Another rat study showed ulcer-preventing effects when ulcers were induced with aspirin (23).
So far, there are no studies evaluating licorice specifically in horses with ulcers (21). More research is needed to understand how it may benefit horses suffering from gastric ulcers.
References:
- Medina B. et al. Effect of a preparation of Saccharomyces cerevisiae on microbial profiles and fermentation patterns in the large intestine of horses fed a high fiber or a high starch diet. J Anim Sci. 2002.
- Setright R. Prevention of symptoms of gastric irritation (GERD) using two herbal formulas: an observational study. J Aust Tradit Med So, 2017.
- McCullough R.W. Expedited management of ulcer, colic and diarrhea in 209 horses: An open-labelled observational study of a potency-enhanced sucralfate-like elm phyto-saccharide. J Vet Med Anim Health. 2013.
- Zaghlool, S.S. et al. Protective effects of ginger and marshmallow extracts on indomethacin-induced peptic ulcer in rats. J Nat Sci Biol Med. 2015.
- Deters, A. et al. Aqueous extracts and polysaccharides from Marshmallow roots (Althea officinalis L.): Cellular internalisation and stimulation of cell physiology of human epithelial cells in vitro. J Ethnopharm. 2010.
- Samardzic, S. et al. Antioxidant, anti-inflammatory and gastroprotective activity of Filipendula ulmaria (L.) Maxim. and Filipendula vulgaris Moench. J Ethnopharm. 2018.
- Barnaulov, O.D. and Denisenko, P.P. Anti-ulcer action of a decoction of the flowers of the dropwort, Filipendula ulmaria (L.) Maxim. Farmakol Toksikol. 1980.
- Lin P.H. et al. Zinc in wound healing modulation. Nutrients, 2018.
- Sharir H. et al. Zinc released from injured cells is acting via the Zn2+-sensing receptor, ZnR, to trigger signaling leading to epithelial repair. J Biol Chem. 2010.
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- Yazdanpanah K. et al. Efficacy of Zinc Sulfate in Peptic Ulcer Disease: A Randomized Double-Blind Clinical Trial Study. J Clin Diagn Res. 2016 Aug.
- D J Frommer et al. The healing of gastric ulcers by zinc sulphate. Med J Aust. 1975 Nov 22.
- Yazdanpanah K. et al. Efficacy of Zinc Sulfate in Peptic Ulcer Disease: A Randomized Double-Blind Clinical Trial Study. J Clin Diagn Res. 2016 Aug.
- Loftin P. et al. Evaluating Replacement of Supplemental Inorganic Minerals with Zinpro Performance Minerals on Equine Gastric Ulcers. J Vet Intern Med. 2012.
- Yang B.R. & Kallio H. Composition and physiological effects of sea buckthorn (Hippophae) lipids. Trend Food Sci Tech, 2002.
- Xing J. et al. Effects of sea buckthorn (HippophaÎ rhamnoides L.) seed and pulp oils on experimental models of gastric ulcer in rats. Fitoterapia. 2002.
- Reese R.E. et al. Effects of seabuckthorn berry extract (Seabuck Complete) on prevention and treatment of gastric ulcers in horses. In: White NA, ed. . Proceedings 9th International Equine Colic Research Symposium. 2008.
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- Ahmad B.A. et al. Reviews of herbal and their secondary metabolites in the treatment of ulcerative colitis and peptic ulcer. J Appl Pharma Sci, 2014.
- Setright R. Prevention of symptoms of gastric irritation (GERD) using two herbal formulas: an observational study.. J Aust Tradit Med So, 2017.
- Munsterman A.S. et al. Evaluation of a Chinese herbal supplement on equine squamous gastric disease and gastric fluid pH in mares. J Vet Intern Med. 2019.
- Aly A.M. et al. Licorice: A possible anti-inflammatory and anti-ulcer drug.. Pharm Sci Tech, 2005.
- Sebai H. et al. Protective effect of artemisia campestris extract against aspirin-induced gastric lesions and oxidative stress in rat.. RSC Adv, 2014.
- Sykes B.W. A free ride: Is long-term omeprazole therapy safe and effective?. Equine Vet Ed, 2021.
- Melo S.K.M. et al. A proton-pump inhibitor modifies the concentration of digestion biomarkers in healthy horses.. J Equine Vet Sci, 2014.
