If you have previously suffered from gastric ulcer or heartburn, then you must be very familiar with the discomfort and pain that is associated with excessive acid in the stomach. Just like humans, horses are also at risk of developing gastric ulcers. These animals constantly secrete gastric acids, in the presence or absence of food in the stomach. The stomach of horses functions the same way whether they eat little, roam the plains, eat large meals or just move around all day.
Horses have naturally evolved to ingest a low-starch, high fiber ration on a continual basis. Searching for food is pertinent in maintaining a healthy digestive tract because the large volume of saliva produced when chewing helps in buffering the gastric acid that is secreted in the stomach of the horse.
The way we manage and keep horses shows that they cannot exhibit their natural food search behavior, and they are often exposed to very high levels of stress when traveling on them or during training. Also, we often feed them rations that are high in starch and cereal levels with less optimum forage.
Risk Factors
Forage Feeding
When horses are fed with pasture and hay, they secrete about 400 – 480g of saliva per 100g of dry matter they consume. But when fed with a concentrate feed, they secrete half as much saliva. This, therefore, reduces the buffering capacity of the saliva. Alfalfa can increase saliva’s buffering potential, because of its high calcium content.
Due to the low calcium and protein content of straw, horses fed with straw as the only source of forage has been observed to have an increased risk of a gastric lesion, and the rough nature of straw could cause gastric irritation.
Pasture Turnout
Grazing horses generally have less EGUS prevalence. A horse that is allowed to live like a horse will constantly trickle feed and exhibit his natural feeding behavior, which is foraging and frequent chewing. This natural behavior allows for the production of a large volume of saliva which helps to constantly buffer the gastric acid that is continuously secreted in the stomach.
Starch Intake
Intake of starch and cereal has been related to an elevated risk of developing Equine Gastric Ulcer Syndrome in horses. Starch intake of more than 2g/kg of body weight a day was accompanied by a 2 fold increase in the risk of developing EGUS and starch intake exceeding 1g/kg of body weight was accompanied by a 2.6 fold increase in the risk of developing EGUS (Equine Gastric Ulcer Syndrome).
Fasting
Horses trickle feed naturally and therefore constantly chew, eat and continually produce different amounts of stomach acid. When horses chew, they produce saliva which is very important for buffering gastric acid produced in the stomach. But when horses don’t feed, even for short periods, less saliva will be produced, and this will reduce the buffering potential of the saliva leading to a rapid decrease in stomach pH.
Inducing gastric ulceration is achieved by alternating ad-libitum access to hay for about 96 hrs of feed denial and 24 hrs of feed denial. Depriving horses of feed drastically reduces the volume of saliva produced and feed matting to shield the squamous epithelium.
Exercise
An important risk factor of Equine Gastric Ulcer Syndrome (EGUS) has been proposed to be an increase in workload. During exercise, contraction of the wall of the stomach allows gastric acids from glandular mucosa to flow into the non-glandular part of the horse’s stomach leading to gastric acid injury to the unprotected lining of the mucosa. But in horses that were well fed before exercise, a reduced amount of acidic injury was noticed in them.
Breed, Age, and Gender
Research shows that there is an increased prevalence of EGUS among young horses between the age of 2-6 years. But this study was limited to only racehorses, while some researched the risk of developing EGUS increases with an increase in age. A study on normal horses showed no relationship between breed, gender, and age.
Clinical Signs
Clinical signs of Equine Gastric Ulcer Syndrome (EGUS) vary, depending on breed, temperament, age, and the horse’s gender. Some horses show less obvious signs even with substantial ulceration while other horses may show more obvious signs with just little ulceration. Observation shows horses that have glandular lesions have less endurance compared to horses with non-glandular lesions.
Typical signs are:
- Failure to thrive or weight loss
- Compromised eating behavior or poor appetite
- Unstable temperament
- Low performance
- Mild colic
- Abdominal discomfort to grooming or girthing
How to Diagnose Gastric Ulcers in Horses
Diagnosis of gastric ulcers can be done by a qualified veterinary doctor Who will perform gastroscopy. The best way for the vet doctor to accurately determine the presence and severity of gastric ulcers is through scoping. However, it is important to note that other parasites and diseases of the hindgut could be at play that gastroscopy cannot rule out.
Also, a fasting period of about 12 hours or more will be recommended by the vet doctor prior to gastroscopy, and as well recommend that you withhold water 4 hours prior to the procedure.
