Gastric Ulcers in Horses: Recognizing and Preventing

Gastric Ulcers in Horses: Recognizing and Preventing

Sep 21, 2023Valerie De Clerck

Studies have shown that nearly 70% of sport horses have gastric ulcers [1]. Gastric ulcers are highly painful and can lead to decreased performance, reduced appetite, colic, and other health issues. Read on to learn how gastric ulcers can develop, how to recognize them, and what you can do to prevent them.

What are Gastric Ulcers in Horses?

Gastric ulcers occur when the stomach's lining is damaged due to continuous production of gastric acid, resulting in inflammation that can range from superficial to deep.

How to Recognize Gastric Ulcers in Horses?

The most recognizable symptoms of gastric ulcers in horses include:

  • Decreased appetite

  • Weight loss

  • Poor performance

  • Yawning

  • Teeth grinding (especially in foals)

  • Pain or biting when girthed (known as girthiness)

  • Dull coat

  • Recurring colic

If you suspect gastric ulcers, it is important to contact your veterinarian. They can use an endoscope to examine the stomach and determine the severity of the condition.

How do Gastric Ulcers Develop in Horses?

Gastric ulcers develop when the normal acid production in the stomach is not adequately buffered or when the contents of the intestine reflux back into the stomach during transport [4]. Buffering refers to the protective mucus layer along with saliva that should shield the gastric lining from the acidic contents.

Causes of Disrupted Stomach Acid Production in Horses

Disrupted stomach acid production can occur due to excessive stress and an imbalance between concentrate feed and forage. Saliva production is highest when horses consume forage such as hay and grass, and it needs to be promoted to prevent direct action of gastric acid on the stomach lining [1,2].

Transport as a Cause of Gastric Ulcers in Horses

New data suggests a correlation between transport and gastric ulcers. It has been observed that the reflux of bile acids into the stomach during transport, along with disrupted gastric emptying, damages the gastric mucosa and increases susceptibility to gastric ulcers [4].

How to Prevent Gastric Ulcers in Your Horse?

1. Allow Your Horse to Chew Throughout the Day

To prevent gastric ulcers, your horse should be able to chew throughout the day. The saliva produced while chewing helps reduce stomach acidity. Therefore, provide your horse with constant access to forage (e.g., hay) (minimum 9 kg for a 600 kg horse). Ideally, offer forage in a slow feeder or hay net to keep your horse occupied [1,5].

2. Use Alfalfa to Buffer Stomach Acid

Alfalfa has a high calcium content, which helps neutralize stomach acid. Choose alfalfa without molasses, as horses do not require additional sugars [1,5].

3. Limit the Amount of Concentrate Feed

For a 500 kg horse, the daily concentrate feed should not exceed 2.5 kg, with a minimum of 6 hours between feedings [1,5].

4. Provide Roughage During Transport

When transporting your horse, offer roughage and ample drinking water until just before loading. If possible, provide roughage and drinking water during transport as well [1-2].

5. Ensure a Stress-Free Environment

Ideally, provide an environment where your horse has social contact with other horses [2,5].

6. Maintain Stomach Health with Probiotic Supplements

Support gastric health with Guts&Glory, a natural supplement rich in pre- and probiotics to support both the gastric mucosa and the flora.

How to Treat Gastric Ulcers in Horses?

The treatment involves a combined approach of medication to inhibit gastric acid production and an adjusted diet plan with the appropriate supplements [5]. Contact your veterinarian for a customized treatment plan for your horse.

Scientific references:

[1] Nieto J., et al., (2004) Prevalence of gastric ulcers in endurance horses – a preliminary report, The Veterinary Journal, Volume 167 (1), 33-37, ISSN 1090-0233,

[2] F. M. Andrews and others, Gastric ulcers in horses, Journal of Animal Science, Volume 83, Issue suppl_13, June 2005, Pages E18–E21,

[3] RJW Bell, JK Kingston, TD Mogg, NR Perkins. (2007) The prevalence of gastric ulceration in racehorses in New Zealand. New Zealand Veterinary Journal 55:1, pages 13-18.

[4] Padalino B, Davis GL, Raidal SL. Effects of transportation on gastric pH and gastric ulceration in mares. J Vet Intern Med. 2020 Mar;34(2):922-932. doi: 10.1111/jvim.15698. Epub 2020 Feb 3. PMID: 32009244; PMCID: PMC7096603.

[5] Buchanan R.B, Andrew F.M . Treatment and prevention of gastric ulcer syndrome. Vet clin Equine 19 2004.

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