Is your horse not performing to their full potential? Are they reluctant to train, kick or fuss when you’re doing up their girth or just seem out of sorts?
Did you know that the prevalence of gastric ulcers in horses has been estimated to be from 50 per cent to 90 per cent, depending on the type of athletic activity horses are engaged in?
Horses kept in stables, i.e. racehorses and show horses, and horses exercised on an empty stomach are the most affected.
Clinical signs are often subtle and nonspecific, such as a slight attitude change, a reluctance to train, an unexpected decrease in performance, but sometimes there are no symptoms at all.
In addition to this, using anti-inflammatory drugs, such as Bute (phenylbutazone), exacerbates gastric ulcers.
The only way to diagnose gastrointestinal ulcers is by endoscopy, which allows us to visualise and assess the stomach lining.
Luckily, there is a very effective treatment for gastric ulcers, a proton pump inhibitor called Omeprazole that is given once a day, either at a treatment dose or a prevention dose.
Why are horses so predisposed to gastric ulceration?
To understand why horses are so predisposed to gastric ulceration, it’s important to understand the anatomy and physiology of the horse’s stomach.
Horses are built to graze, so the stomach of the horse is quite small and produces a steady flow of acid for digestion. The grass that the horse grazes upon throughout the day neutralises this flow of acid.
The horse’s stomach is divided into two regions. There is the squamous region, and the glandular mucosa.
The squamous region is basically a continuation of the oesophagus, whereas the glandular mucosa is, as the name suggests, glandular and secretes gastric acid. It also produces mucus and bicarbonate, and this is what protects the glandular mucosa from ulceration.
The squamous region, however, is very thin and doesn’t have any protective mechanisms. Given that the horse produces gastric acid at all times, even when not eating, all horses are incredibly vulnerable to ulceration in the squamous region.
So you can see that when a horse only receives two or three feeds per day, the stomach is subjected to prolonged periods of acid production with no feed to neutralise the acid.
Other factors have also been show to increase the risk of ulcer development. These include stress - such as transport stress and the stress of confinement - and long-term use of non-steroid anti-inflammatory drugs such as Bute (phenylbutazone).