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In the past, gastric ulcers (Equine Gastric Ulcer Syndrome, EGUS) were primarily associated with racehorses, but today we know they are more common among sport and leisure horses, and even weanlings, than previously thought. It is estimated that about half of all horses suffer from gastritis or gastric ulcers. Rarely will you find clear symptoms like colic. In most cases, the signs are so subtle that they are not noticed or not associated with stomach ulcers.

What signs in my horse might suggest stomach ulcers?

Disapproval of food

If the horse dislikes or refuses unfamiliar feed after one or two days, if it alternates between eating concentrated feed and hay or refuses starchy concentrated feed.

Soft cow hay instead of hard horse hay

Affected horses often prefer soft, leafy hay and avoid the hard, stalky hay that you would typically feed horses. Stalky hay can also cause faecal water in these horses, which improves when the hay is changed to leafy hay (second cut).

Strange behaviour during or after feeding

Some horses may show the flehmen response while eating, especially when consuming concentrated feed. Others may lick the bars of the stable or the salt stone between bites of concentrate feed or after eating.

Very slow eating

Horses eating remarkably slowly, taking long breaks, avoiding hay, or spending hours sorting through hay to eat leaves but leaving the stalks, it can also be a sign.

Profuse salivation or empty chewing

Some horses show “empty chewing” throughout the day, making chewing movements without food in their mouths. This is an attempt to produce saliva, which buffers the (painful) stomach acids.

Horse eats manure from the ground
If horses consume manure in an attempt to ingest something into their stomach, it may be an indicator of stomach ulcers.
© ShirleyF / AdobeStock

Eating manure or sand

Horses may eat faeces (their own or others’) or the floor of the paddock when lacking hay. All alarmbells should go off in this case! This behavior indicates severe roughage deficiency and suggests potential severe stomach ulcers. Otherwise, they would not try to fill their stomachs with faeces or sand.

Constipation colic in winter

Healthy horses prefer cold water over warm water. Horses with stomach ulcers stray from this rule: they avoid drinking cold water, often only drink in small sips and overall drink too little and too rarely. This can lead to impaction colic, particularly in winter. If your horse prefers warm water (even when cold water is available) and drinks a large amount, like 10-20 liters in one go, you should consider stomach ulcers. The same applies if the horse willingly eats soaked feed like hay cobs when warm but refuses them when cold.

Free Faecal Water Syndrome (FFWS)

Stomach ulcers can affect the large intestine due to stress. Faecal water resistant to treatment might indicate this condition, as well as faecal water that worsen when stalky hay or straw is fed, but improves or disappears when soft, leafy (cow) hay is fed.

Emaciation / poor weight gain despite good feeding

While some horses naturally keep weight easily or badly, if a horse is well-fed with proper hay quality and quantity, yet loses weight or remains ribby, stomach ulcers should be considered rather than dismissed as just being a natural hard keeper.


Many behavioral problems such as cribbing, weaving, running in circles, or even self-destructive behavior are caused by prolonged stress. This stress can also lead to stomach ulcers, which often persist even after the initial stress has ceased (just like the behaviour also remains). Virtually every horse with behavioral issues likely also has stomach ulcers.


Girthiness is often labeled as a behavioral problem. Usually, the behaviour is simply stopped by cross tying the horse, ensuring it can’t bite anybody. However, horses are trying to communicate with us through their behaviour. In this case the horse may be trying to communicate discomfort, saying: “It hurts me when you tighten the girth.” This could also be due to highly inflamed stomach.

A “ticklish” stomach

Many horses dislike having their bellies groomed.
This is especially noticable in summer, when biting insects like to target the belly, causing itchiness for the horse. Most horses like to have their bellies scratched and srubbed to relieve the itch. But not the horses with stomach aches. If your horse is sensitive to touch at the belly, think of the stomach – a horse’s belly isn’t actually “ticklish”.

” Tight” walking, especially at the start of the training

There can be several reasons why horses have a prolonged warm-up period, ranging from prolonged standing in the stable to an unsuitable saddle to osteopathic blockages. However, if a horse with a “tightened handbrake” also displays other characteristics from this list, stomach ulcers could be a possible cause. After all, who enjoys jogging with a stomach ache?

If you suspect your horse has stomach ulcers, consult a competent therapist.

Many “miracle cures” are available, but they often only provide temporary relief or even exacerbate the problem. A successful therapy for gastritis or gastric ulcers should first address the underlying causes (living conditions, feeding management, stress, etc.) and consequently calm the inflammation and promote the healing of the gastric mucosa.

Team Sanoanimal
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