Hindgut ulcers in horses – treatment and prevention.


Hindgut ulcers in horses

From pony club to high performance, hindgut ulcers in horses can present a large problem. The signs can be subtle but left untreated can cause major health problems for the horse. In order to treat the problem it’s important to understand how it happens in the first place.

Hindgut Acidosis

A hindgut high in acid can be due to increased starch in a horses diet. This is most commonly caused by a diet high in grain and low in roughage and affects about 60% of performance horses.

Fibre is a horses friend

A horses gut is designed to consume a diet high in fibre (hay, grass etc.). Fibre ferments in the hindgut and then converts into useable energy. As horses have become more domesticated and their diets have altered (e.g. the addition of grain), they are eating less fibre and more starch.

The recommended standard for starch in a horses diet is 1-1.5g/kg of body weight per meal. Starch is normally digested in the small intestines, but when it is consumed in large amounts some will have to move to the large intestines for processing.

Rolling horse - collic

Hindgut acidosis is often overlooked

What is acidosis?

When starch is fermented it produces lactic acid. More starch means more lactic acid which lowers the pH and changes the type of microbes in the hindgut. The pH number is simply a measurement from 0 to 14 of how acidic or alkaline something is: Neutral is 7, acidic is low and alkaline is high.

A horses gut should sit between 6.5-7; the microbes in the horses gut work best in this environment and they are crucial to digestion and energy production. If the pH drops (more acidic) the bacteria are less productive and can begin to die off. The death of the good bacteria causes endotoxins to be released. There are also bacteria which produce and use lactic acid – and they thrive in an acidic environment – making the gut more acidic again.

Increased acidity in the hindgut damages the gastric wall which absorbs the endotoxins. These endotoxins start a series of inflammatory responses and start to trigger health problems…this can cause hindgut ulcers in horses

Signs and symptoms

A horse with increased acidity in its hindgut can show:

    • Colic symptoms
    • Decreased appetite
    • Poor performance/condition
    • Crib-biting and wind sucking
    • Slower recovery from exercise


Hindgut acidosis is often overlooked as the above symptoms aren’t always obvious as acidosis. Testing the pH of the horses manure is a quick and easy way to diagnose acidosis if your horse is showing the above symptoms.


Address the initial problem

    • Limit starch to the recommended intake levels.
    • Feed grain in small amounts and regularly (up to 2.5kg/day).
    • Grains should be processed – look for pelleted, extruded or micronised as they are more easily digested by horses.
    • Access to roughage – minimum intake of 1.5% of their body weight daily.


Sucralfate is a cytoprotective agent for the symptomatic treatment of equine gastric ulcer syndrome, small intestine, hindgut and colonic ulcers (right dorsal colitis). When sucralfate is administered in conjunction with omeprazole, sucralfate will coat the ulcer which avoids further acid damage and allows the omeprazole to treat the cause.When ingested, the acidic environment forms a thick viscous compound that adheres to the ulcer site, acting as a protective film, providing protection for up to six hours at a time.

Prevention is always better than cure. Make sure your horse is consuming adequate roughage and monitor your horse closely if you are concerned about any changes in their health.

Abler Watermark - Est. 2008




About Author

Betsy OReilly, Managing Editor of Blog Abler dedicated to Equine Ulcers. Born and bred in country Victoria, Australia, is a lifelong horse owner who has dabbled in Pony Club and Horse Racing. Enjoys hearing and writing about Equine Ulcers.

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