Equine Gastric Ulcers | BioStar US

Equine Gastric Ulcer Syndrome and Your Horse

I remember the first time I heard the words: “I think we need to treat your horse for ulcers.”  It was 1997 and I was in Europe training with my horse, Lionheart. The Belgian vet based his determination on what I had described: tight back, girthy, not eating well, laying his ears flat back when I tried to brush him, balking under saddle.  Lionheart refused to stand for the vet’s examination. He turned a grumpy eye towards him and kicked out as the vet went over the acupuncture points.

We know a lot more about Equine Gastric Ulcer Syndrome than we did twenty years ago.  The prevalence of this condition is estimated to be 65-70% of performance horses and 90% of racehorses.

We know stress is at the root of the prevalence of gastric ulcers.  Research has shown that horses kept in confinement, with limited access to grazing, large quantities of grain intake, shipping, competing, fasting longer than 4 hours in a 24 hour period, use of NSAIDs, environmental stressors, and changes in routine can lead to the formation of gastric ulcers.

How can we as horse owners help our ulcer prone horses?

Familiarizing yourself about common symptoms and treatment practices is an important first step to protecting your horse against Equine Gastric Ulcer Syndrome. There are several management techniques and nutritional practices that will help support your horse as a preventative or post ulcer treatment. In addition, BioStar is formulating a new supplement — Optimum GI —  as part of our multivitamin/mineral Optimum line, with specialized GI support. Ingredients in Optimum GI support gastrointestinal health as well as provide essential vitamins and minerals.

Not all gastric ulcers are the same

The horse’s stomach is divided into two parts: the upper third of the stomach known as the non-glandular portion, or squamous mucosa, and the glandular lower portion of the stomach.  Ulcers in these two areas are known as Equine squamous gastric disease (EGSD) and Equine glandular gastric disease (EGGD).

equine gastric ulcer syndrome | BioStar US


The non-glandular portion of the stomach, the squamous region, is unprotected from gastric acid.  Some researchers liken ulcers in the squamous portion in horses to gastroesophageal reflux disease (GERD) in humans.  Stomach acids are produced continually in horses, not just when they eat.  Squamous ulcers — and equine gastric ulcer syndrome — can appear simply by stomach acid splashing the stomach lining.

Research has demonstrated that excessive exposure of the squamous region to the gastric acid being pushed up by the increased intra-abdominal pressure associated with trotting and cantering and can contribute to the formation of squamous ulcers.

When horses eat or graze, their saliva produces bicarbonate that helps neutralize the acid, thus protecting the squamous region.  It is estimated that horses produce 3 gallons of saliva per day.

Racehorses have an increased prevalence, lesion severity, and number of lesion sites within the squamous region, which is associated with the intensity of long-duration training. Likewise, research has shown that the severity of squamous ulcers in endurance horses can be particularly severe related to the distance of the ride.


The glandular portion of the stomach is protected from stomach acid by mucus.  However, the glandular portion is affected by stress, dehydration, and diet. High carbohydrate diets can create short-chain fatty acids in the stomach that can erode the stomach lining.

Horses fed grain-based feed produced half as much saliva as horses fed hay and fresh grass.

Two different types of equine gastric ulcer syndrome

Equine squamous gastric disease (ESGD) and equine glandular gastric disease (EGGD) are separate and distinct diseases.  According to a consensus statement published in the UK-Vet Equine (Rendle, Bowen, Brazil, Conwell, Hallowell, Hepburn, Hewetson, Sykes. 2018):

Warmblood horses have been identified to have a higher prevalence of EGGD (Luthersson et al, 2010).  Performing exercise more than 4 or 5 days per week was found to be a risk factor for EGGD in racing Thoroughbreds (Habershon-Butcher et al, 2012) and show jumpers (Pedersen, 2015).”

Some studies have shown that horses with severe EGGD have greater increases in cortisol, but it is not yet known if EGGD causes cortisol levels to rise or whether higher cortisol from stress causes EGGD.

In a study conducted on Thoroughbreds in the UK and Australia, it was identified that exercising more than 5 times per week was associated with a tenfold increased risk of EGGD (Sykes, Bowen, Habershon-Butcher, Green, Hallowell. 2019).

equine gastric ulcer syndrome | BioStar US

Equine Ulcer Treatment

Horses with ESGD respond well to Omeprazole (Gastro Guard) and the success of omeprazole in healing squamous region ulcers is well documented.

However, Omeprazole does not seem to have the same results when used as a mono-therapy for EGGD.  The European College of Equine Internal Medicine Consensus Statement, published in the Journal of Veterinary Internal Medicine (2015) recommends the combination of sucralfate, a mucosal protectant, with Omeprazole for EGGD.

Several veterinarian researchers point out that sucralfate should be given separately about 1.5 hours after the omeprazole because it can negatively affect the absorption of omeprazole.

One of the concerns of using omeprazole as a singular therapy for EGGD is that it has shown to not be effective by itself.  And there are concerns of its use as a prophylactic (preventative).

The efficacy of omeprazole as a prophylactic for EGGD is unclear with 23% of horses experiencing worsening of their EGGD grade in a series of recent studies.” (Sykes, Hewetson, Hepburn, Luthersson, Tamzali. 2015)

Long-term use of Omeprazole

Omeprazole is a proton pump inhibitor, whose actions are to reduce stomach acid production.  Long-term use of omeprazole can reduce the horse’s ability to digest food. Acid is important for the pre-digestion of proteins and fats, activating enzymes, and provides an inhospitable environment for some pathogenic microorganisms.

ESGD and EGGD commonly recur once drug administration ceases. According to some veterinarians, recurrence can happen within days after treatment period is over.

Management strategies:

  • Grain and concentrate feeds should be fed an hour after feeding hay to take advantage of the buffering action of forage.
  • Alfalfa hay has a protective effect by buffering stomach acids.
  • Horses need to be fed more than twice a day.  Feeding four or more times a day can lessen the recurrence of ulcers.
  • Horses that get 6-10 hours a day of turnout can lower their risk of ulcer recurrence.
  • Horses that have access to forage or hay 20 hours a day can reduce the occurrence of gastric ulcers.
  • Supplemental dietary fats (oils) can be helpful in preventing glandular ulcers.  Dietary fats appear to be less helpful in preventing squamous gastric ulcers.
  • Digestible carbohydrates in high-concentrate feeds can cause acid damage to squamous mucosa because of the production of volatile fatty acids.
  • High protein and high calcium diets have shown to reduce incidence of both squamous and glandular ulcers.

Stall confinement

Horses living together in pastures have a decreased prevalence of gastric ulcers.  Researchers have suggested that part of the decreased risk of ulcers in horses living in a group is because they are continually moving and eating, plus their physicality with other horses leads to bonding and support.

While stall walls provide safety, they also enhance isolation.  When we prevent horses from touching each other, relying solely on human touch and grooming, we are separating them “from the herd.”  We deprive them of the very basic need among herd animals of each other’s company.

equine gastric ulcer syndrome | BioStar US

Nutritional support:

  • Research shows that higher protein and calcium are beneficial for horses that are ulcer-sensitive, and/or ulcer-prone.
  • Increasing dietary oils such as flax oil, coconut oil, camelina oil, or hemp seed oil may help prevent glandular ulcers.
  • We know the amino acid glutamine plays an important role in healing gastric and intestinal mucosa.
  • We know that aloe can be beneficial in providing a coating action in the GI tract.  However, all aloe is not equal and it is virtually impossible to tell from a label.  BioStar only buys medical grade aloe that is used in hospitals.
  • According to an article published on the TheHorse.com, pectin and lecithin administered for 30 days resulted in lower ulcer scores compared to un-supplemented counterparts (Liburt. 2019).

Research into the mushroom Lion’s Mane, used in Traditional Chinese Medicine for ulcers, has identified polysaccharides in Lion’s Mane can protect against gastric ulcers.  Among the most well known polysaccharides is beta glucan.  A study published in the March 2017 issue of the Journal of Equine Veterinary Science demonstrated that a polysaccharide blend showed 90% complete resolution or improvement in ulcerated gastric areas in horses (Slovis. 2018).

BioStar’s Optimum GI

We took the research on equine gastric ulcer syndrome and formulated a supplement that combines important bioavailable minerals and nutrients for health and well-being with specific gastric support.

Quality matters

Real, whole food ingredients make an enormous difference in health, performance, and well being.  The sources of our raw materials are carefully researched and tested.  Each ingredient is chosen for superior quality and sustainable sources, with “farm to table” traceability. In our new Optimum GI formula, BioStar uses true mineral proteinates for higher bioavailability, pharmaceutical grade pectin, specifically chosen wood-grown mushrooms, and Vitamin A and D that come from plant sources, not petroleum. We always choose non-GMO and organic ingredients.

cabbage | BioStar USCabbage is one of the richest food sources of the amino acid L-glutamine. It has been found to decrease the progression of pro-inflammatory genes, reducing intestinal damage.


apple | BioStar USApple pectin forms a gel when exposed to acidic environments such as the stomach.  It can bind bile acids, helping to protect the lining of the gastrointestinal tract.  It can also help stabilize the mucous in the glandular region of the stomach.

Apple pectin is available in different grades including feed, industrial, and pharmaceutical grades.  The pectin BioStar uses is 90% pectin, the remaining 10% is fiber from the rind and pulp. Pharmaceutical grade pectin is used primarily in the medical field. Feed grade pectin is only required to contain 30% pectin.  Pharmaceutical grade must be a minimum of 80% pectin.

SunflowerSunflower lecithin (non-GMO) provides phospholipids that play an important role in the extracellular and membrane barriers of the GI mucosa. It can enhance the barrier properties of the mucosa, helping to reduce irritation and inflammation from stomach acids, as well as from pharmacological damaging agents (such as NSAIDs).

Lion's Mane | BioStar USLion’s mane extract is a medicinal mushroom used in Traditional Chinese Medicine.  Lion’s mane has a long history of use for gastric ulcers. Among its important active components are polysaccharides. The primary polysaccharides in fungi are beta-D-glucans, with specific structures that support immune function. Grains such as oats also contain beta-D-glucans, but their structures perform different actions such as maintaining blood-glucose levels.

A study by Hagyard Equine Medical Institute, showed that polysaccharides improved or resolved ulcerated areas and increased appetite, weight gain, and positive behavior changes (Slovis. 2018).  Studies have also demonstrated that beta glucans can reduce gastric damage caused by NSAIDs.

Our Lion’s Mane extract includes both the fruiting bodies and mycelium, and is sourced from a medicinal mushroom grower in China. These mushrooms are grown on the fungi’s primary substrate, wood, instead of cereal grains or rice.  Medicinal mushrooms in China have been grown this way for thousands of years, in contrast to modern methods and artificial environments.

Optimum GI for your horse

Optimum GI provides proteinated macro and micro-minerals for high bioavailability, vitamin D2 from mushrooms, beta-carotene from organic carrots, amino acids from undenatured whey protein, and pumpkin meal for muscles and topline. Optimum GI also supplies Reed Sedge Peat for fulvic and humic acids that assist in mineral absorption and support beneficial colonies of microorganisms in the gut.

Optimum GI provides a range of support for the sensitive mucosa without interfering with normal digestive activity.

Optimum GI EQ for equine gastric ulcer syndrome | BioStar US

Look for Optimum GI’s release this month!


Liburt N, MS, PhD, PAS “Tips for Managing Gastric Ulcers in Performance Horses.” The Horse.com. August 2019.

Rendle DI, Bowen IM, Brazil TJ, Conwell RC, Hallowell G, Hepburn R, Hewetson M and Sykes B. “EGGD consensus statement: Recommendations for the management of Equine Glandular Gastric Disease.” UK-Vet Equine. January 2018. Vol 2.

Slovis NM. “Polysaccharide Treatment Reduces Gastric Ulceration in Active Horses.” Journal of Equine Veterinary Science. March 2017. pp 116-130.

Sykes BW, Bowen M, Habershon-Butcher JL, Green M, Hallowell GD. “Management factors and clinical implications of glandular and squamous gastric disease in horses.” Journal of Veterinary Internal Medicine. January 2019. Vol 33(1) pp 233-240.

Sykes BW,  Hewetson M, Hepburn RJ, Luthersson N, Tamzali Y. “European College of Equine Internal Medicine Consensus Statement—Equine Gastric Ulcer Syndrome in Adult Horses.” Journal of Veterinary Internal Medicine. Sept-Oct 2015. Vol. 29(5). pp 1288–1299.

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