Nutrition and feeding play an integral role in the prevention of equine ulcers. Ulcer-prone horses can benefit greatly from a feeding program that supports gut health and supports the horse’s natural defences against ulcers.

Equine ulcers are painful erosions that develop within the lining, or mucosa, of the digestive tract. Most commonly, horses develop ulcers in the stomach or right dorsal colon. They can cause poor performance, aggression, and girthiness in your horse.

Forage type, meal size, meal composition, and feeding frequency can all impact ulcer risk. These factors are so critical that poor feed management can significantly increase your horse’s likelihood of developing ulcers.

A well-structured feeding program that accommodates species-appropriate foraging behaviors will limit the time your horse spends with an empty stomach. Ensuring that horses have consistent free-choice access to hay or pasture helps buffer against gastric acids that can cause ulcers to form.

Reducing the amount of grain and concentrates in your horse’s diet, ensuring access to water, and feeding certain gut-healthy foods can also defend against ulcers.

Looking for assistance with designing a diet for your horse to reduce their risk of ulcers or promote ulcer recovery? Submit your horse’s diet online and our nutritionists can help!

Ulcer Risk in Horses

Equine ulcers can affect up to 93% of horses, making them one of the most commonly diagnosed digestive health conditions in horses.[1]

Ulcers are characterized as inflammation and erosion that occur along the lining of the gastrointestinal tract. They may form when the mucosal lining has excessive exposure to gastric acids or when the body’s natural mechanisms of protecting the GI mucosa are disrupted.

Ulcers can develop anywhere along the gastrointestinal tract, though they occur most commonly in the stomach. When ulcers occur in the hindgut, this is referred to as Right Dorsal Colitis.

All horses can be affected by ulcers, but some are more prone than others. The following rates of ulcer prevalence have been observed:

  • Endurance horses (competition season): 90-100%
  • Standardbred or Thoroughbred horses: 58-100%
  • Performance horses: 40-60%
  • Endurance horses (off-season): 48 %
  • Pleasure horses: 53%

The higher prevalence in some competition horses attributed to greater exposure to common ulcer risk factors.

The causation of ulcers is often multi-factorial, meaning several interacting risk factors can play a role in any given case of ulcers.

Potential contributing risk factors include:

  • High-intensity exercise
  • Frequent anti-inflammatory drug use (ie. NSAIDs)
  • Stressful social environments
  • Physical stressors (ie. Stall confinement, travel, change in routine)
  • Intermittent access to feed and water
  • Poor feed quality and diet composition
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Why Do Horses Get Gastric Ulcers?

It is widely believed that wild horses are not prone to gastric ulceration, so why do domesticated horses have such high rates of this condition?

Gastric ulcers are unfortunately an artifact of modern equine management practices. The good news is, horse owners and caretakers can take steps to manage horses so their risk of ulcers is minimized and their quality of life and overall health are maximized.

The horse’s stomach continuously produces hydrochloric acid whether there is food in the stomach to digest or not. This creates a highly acidic environment in the stomach that is a major risk factor for ulcer development.

A typical 500 kg (1100 lb) horse can produce up to 60 litres (16 gallons) of gastric acids per day!

Gastric Acids and Ulcers

There are two compartments that make up the equine stomach: the upper squamous region and the lower glandular region.

The glandular region of the stomach produces mucous and bicarbonate to create a natural barrier between the acid and stomach lining, and neutralize stomach acids. This mucus and bicarbonate barrier is par