Weight and/or condition loss in horses is frequently encountered and has numerous potential causes.
Causes can be divided in the following different categories:
There are three main causes of gastric ulcers: stress, diet and exercise.
Stress for horses can be secondary to any chronic or continuous pain or disease, or it can be caused by anything outside their routine, such as transport, relocation, hospitalisation, feeding or management changes.
In the wild, horses constantly graze and therefore continuously produce saliva, which buffers the acid which is continually produced by the cells in the stomach. Modern diets rich of cereals increase the acidity of the stomach and ponies and horses often have periods without food, while the gastric acids are still being produced. This excess acid may cause gastric ulceration.
The stomach of horses is made up of two portions: a squamous region occupying the top third and a glandular one, comprising the bottom two thirds of the stomach, where the gastric acids are being produced. During exercise, the acid may splash on the more sensitive upper part of the stomach.
Clinical signs of gastric ulcers may vary from horse to horse. They include weight loss, poor appetite, mild recurrent colic (flank watching, uncomfortable when ridden, abdominal discomfort), poor coat, change in temperament and poor performance, including a refusal to go forward from the leg.
Diagnosis of gastric ulcers require an examination of the stomach under sedation with a gastroscope, a three-metre-long flexible scope with a camera.
Gastroscopy is a relatively easy and quick procedure, which allows the entire stomach to be visualised.
Under sedation, the endoscope is passed through the nose down to the stomach.
Since the entire stomach will need to be visualised, the horse should be starved for 16 hours prior the procedure and water withheld from two to four hours before.
Some management changes in the feeding regime of the horse may help prevent the development of gastric ulcers.
Roughage is vital to the horse’s diet and if possible, the horse should be turned out at grass as much as possible.
When stabled, the horse should be given hay or haylage frequently, to promote a natural eating pattern. The fibre content of the feed should be increased, while the carbohydrates decreased, and vegetable oil can be added to the diet (up to 200mL twice daily) to protect the mucosa of the stomach.
Additionally, before being exercised, horses can be fed a small amount of fibre, such as chaff or alfalfa, to stimulate the production of saliva, to neutralise the gastric acid and provide a mat in the stomach.
If ulcers are being diagnosed, omeprazole is the only licensed treatment in the UK. It is effective for both treatment and at a lower dose for prevention, but horses racing under the BHA rules are not allowed to compete on treatment. Ulcers in the lower (glandular) compartment of the stomach require sucralfate to be added to the treatment.