Gastric ulcers are one of the most prevalent diseases in racehorses and studies have shown that as much as 100% of racehorses in active training experience gastric ulcers at some point.  Gastric ulcers can be painful and can result in reduced quality of life and poor performance. However, with good management, prevention is possible. In this article we discuss symptoms, diagnosis, treatment and prevention of equine gastric ulcers. 

Gastric ulcers are small painful wounds that form on the stomach lining. While only visible via gastroscopy, and although symptoms can often be vague their presence can be detected by observing a horse’s behaviour.  Research shows that ulcer severity is not necessarily linked to severity of symptoms – this varies from horse to horse. 

The lower part of the stomach produces gastric acid constantly. This is an evolutionary adaptation and is necessary for horses in the wild, as they graze all day, however for stabled horses that feed less frequently, this does not serve them well and it can often be problematic. The production of gastric acid in an otherwise empty stomach without enough fibre in the stomach, or during hard work on an empty stomach, means the gastric acid can start to irritate the sensitive stomach wall and cause ulcers. 

How do you recognise an ulcer? 

Signs of gastric ulcers are often difficult to identify given the wide variety and vagueness of behaviours displayed by horses with the condition, and this can lead to delayed or misdiagnosis.  

The following symptoms may be signs that your horse is suffering from stomach ulcers: 

• Reduced appetite
• Pain during girthing or when the belly is touched
• Stretching as if to urinate
• Difficult behaviours during training 
• Drop in performance
• Dull coat 
• Grinding teeth or yawning
• Weight loss
• Behaviours associated with colic
• Loose stools
  

Given the prevalence of gastric ulcers in racehorses, it is always worth an investigation for the condition, even if to rule it out.  If these symptoms persist, contact a vet for a diagnosis and a treatment plan, if needed. 

Correct diagnosis is key! Note that a gastric ulcer can only be diagnosed by means of a gastroscopy. Bloodwork, faecal samples, or saliva tests will not yield accurate diagnoses. A gastroscopy is also important to see where the lesions are located in the stomach. Indeed, the ulcer’s location determines which treatment would be the best.

Gastric ulcers from mental stress

Horses are creatures of habit, and they require a consistent daily routine for their mental well-being. Change (change of yard, herd mates, owner, frequent transport to unfamiliar locations, etc.) can cause mental stress. Being flight animals, horses have extremely sensitive nervous systems. The brain and the digestive system are also closely connected. For example, a horse under acute stress will quickly produce loose droppings. 

Mental stress quickly triggers the nervous system and causes the release of stress hormones. Cortisol acts on these nerve pathways, stimulating gastric acid production but also affecting the integrity of the protective layers of the stomach. As long as the stress is temporary, it usually is not a problem. However, if the horse suffers from tension or stress for an extended period of time, it can develop stomach ulcers.

What can you do about an ulcer? 

A stomach ulcer will require a visit from your veterinary surgeon. Vets often recommend omeprazole, a medication that stops the production of gastric acid, giving the stomach time to heal. Omeprazole has certainly proved its worth in the short term. It is the only FDA-approved drug with scientific efficacy in curing gastric ulcers.

Like any drug, Omeprazole use can bring its own risks, and prevention by nutrition management is much more beneficial than long-term use of omeprazole. The stomach needs acid for proper digestion so completely inhibiting the production of acid does not help digestion longer term. Moreover, the sudden discontinuation of omeprazole may lead to a significant increase in gastric acid production, or a rebound effect, compounding the problem. Ensuring a horse’s ration contains sufficient fiber and limiting sugar and starch is a good way to prevent this. The more the horse has to chew, the more saliva is produced, and saliva production  buffers and neutralises excess gastric acid production, which can help to prevent recurrence of gastric ulcers.

The importance of forage
Forage (fiber) is the largest component of a horse’s daily ration. Research shows that the type of forage matters. The most important factor is that forage provides structure. This creates a thick, strong fibre layer in the stomach, forming a natural barrier against splashing stomach acid. Furthermore, the more complex the fibre, the more the horse will chew and salivate.

Straw

Straw increases the risk of developing gastric ulcers. Straw makes a nice extra to nibble on throughout the day, but your horse’s feed ration should never be 100% straw.

Alfalfa

Alfalfa’s  higher calcium and protein content results in a buffering effect, making it useful as a feed for horses prone to gastric ulcers. A word of caution, however: Alfalfa is richer than grass hay and is not suitable for all horses, for example those prone to tying up (or RER). Alfalfa hay is a wiser choice than pellets or cubes, because hay has more structure. Sometimes Alfalfa hay can be cut very young and contain mostly leaves instead of stems. In this case, choose more textured grass hay or a mix of both so that your horse’s ration has enough structure.

Grass hay
Grass hay often has more structure (and thus fibre) than Allfalfa. This makes grass hay a more suitable source of roughage. 

Beet pulp 

Research shows that beet pulp can lower the risk of gastric ulcers. It is a useful source of roughage that also provides energy. It is high in fibre; however it needs to be soaked before being fed to the horse.

Quick Facts about Gastric Ulcers

• Although invisible from the outside, gastric ulcers can have an enormous impact on a horse’s performance and well-being 
• 60–90% of horses suffer from gastric ulcers 
• Through careful observation you can recognise the symptoms of gastric ulcers 
• Stomach ulcers can be caused by stress, diet, hard training, or some non-steroidal anti-inflammatory drugs (NSAIDs) 
• Fibre plays a key role in prevention and treatment
• Once gastric ulcers have been diagnosed, it is more likely that they will return.  
• Treat gastric ulcers preventively. No fasting: to prevent acid from attacking the stomach lining, the stomach should never be empty

Advice from our experts: fibre plays a key role in prevention and treatment, with supplements in a strong supporting role 

Prevention is better than a cure, so providing a healthy stomach environment and you can avoid many problems. In this Science Sunday, you have already read about the importance of fibre. But did you know that supplements (and even Cavalor concentrates) can be quite helpful in preventing gastric ulcers? Supplements can have a buffering effect. Give these to your horse shortly before the big event, training, or transport. 

What about preventive administration? Here too, timing is key, because their buffering effect will often be shorter than that of fibre. Give your horse supplements early in the morning (when the acid level is naturally lower) and ideally before feeding him concentrates. Horses eat less at night and so administering the supplement late in the evening can also help.  

We developed Gastro Aid especially for the equine stomach. It is available as a paste, powder or liquid. 

Cavalor Gastro Aid creates a healthy environment in the stomach by neutralising gastric acid and protecting the stomach wall. A horse’s stomach produces acid continuously, making it very susceptible to developing wounds or sores. This paste was developed for horses suffering from stomach ulcers and loss of appetite. Once the horse has recovered and is eating better, you can switch from the paste to the powder or liquid version.

The liquid and powder versions can also be used as daily preventive measures for horses prone to stomach ulcers. Unlike omeprazole, it does not shut down stomach acid production, but works to protect the stomach from acid damage.

The herbs in Cavalor Gastro Aid help to protect the stomach wall against excess acid. They provide extra support for the stomach by stimulating saliva production and promoting the healing of ulcers.

Whilst concentrates are often seen as ‘risky’ when talking about gastric ulcers, Cavalor FiberForce Gastro actually helps in their prevention and treatment.
 

Cavalor FiberForce Gastro is a high-fibre mix for healthy stomach function. Its high-fibre composition includes a mix of lucerne and teff grains, beet pulp, and 8% timothy stalks, ideal for stimulating saliva production and neutralising stomach acid. This combination of herbs protects the stomach lining against irritation and helps to maintain a neutral pH value in the stomach.

Cavalor FiberForce Gastro is low in starch and sugar to keep glucose and insulin levels in balance. FibreForce Gastro is ideal for horses with stomach problems. It also contains tasty fenugreek to stimulate the appetite. Its extruded cereals ensure good digestion – no whole grains.