Does your horse struggle to hold condition, have a dull coat, tend to get grumpy or fractious, be reluctant to work or have reduced performance? All of these symptoms may be signs of gastric ulcers as well as intermittent colic and reduced appetite, although some horses may show no obvious visible signs.
With the approach of winter many of our horses will be spending longer periods stabled which brings with it both advantages and disadvantages for the horse owner. Horses have evolved as trickle feeders that will spend up to 18 hours of their day grazing and their digestive system is designed for a continuous supply of high fibre food. Modern management systems mean that many horses, especially performance horses, may spend the majority of their time stabled and are often fed diets that are high in starch but low in fibre, meaning that they may spend considerable time with empty stomachs.
By looking at how the horse’s stomach works we can understand how gastric ulcers occur. The horse’s stomach is divided into two distinct parts: the lower part of the stomach is referred to as the glandular area which is where gastric acid is continuously produced via glands – whether the horse is eating or not, research has found that an adult horse secretes approximately 1.5 litres of gastric juice each hour. The glandular area is protected from the effects of gastric acid by a protective coating of mucosal cells. The upper part of the stomach is known as the non-glandular or squamous area and should be alkaline, this area does not have a protective coating and relies on the buffering effect of saliva to protect it from the gastric acid that is being continuously produced.
Gastric ulcers are an erosion of an area of the stomach lining and the depth of the erosion determines the severity of the ulcer. Gastric ulcers have been identified in all areas of the stomach, however, not surprisingly gastric ulcers tend to be most common in the upper, non glandular, squamous part of the stomach which lacks the protective coating. Saliva is the horse’s natural buffering agent against gastric acid in the upper, non glandular part of the stomach, however saliva is only produced when the horse is actually chewing and fibrous feed stuffs require more chewing than concentrate feeds, for the stabled horse who may not have free access to forage, especially as in the case of performance or racehorses this can cause a problem. You may well be thinking ‘but I don’t own a high performance horse or racehorse’ but this scenario is often all too common to the regular leisure or riding club type horse, how often have you found that your horse has run out of hay bythe time you get to the yard in the morning?
Opinions vary on the incidence of horses affected by gastric ulcers, but some research reports the figures being as high as 90% for racehorses in training, up to 60% for competition horses and from 25% - 50% for foals.
Stress also has a part to play in increasing the likelihood of gastric ulcers. It has been shown that horses in a stressful training programme have increased levels of corticosteroids and a subsequent reduction in blood flow to the stomach lining which interferes with the protective coating and leads to more damage from the gastric acid. Other stressful situations such as travelling, weaning and stabling can also cause similar effects.
The only definitive way to diagnose gastric ulcers is with gastroscopy, which involves placing an endoscope into the horse’s stomach and looking at its surface.
So what can you do as a horse owner to help reduce the likelihood of stomach ulcers?
Mimicking the horse’s natural lifestyle is key to preventing gastric ulcers. 24 hour turnout is ideal and the majority of horses can be worked and competed successfully whilst living out, if constant turn out is not an option you should still try to ensure that your horse spends as much time out in the paddock as possible. Whilst your horse is stabled provide ad lib forage which will promote saliva production, the horse’s natural buffer against gastric acid. It is also important to remember to provide your horse with forage whilst travelling which can be a potentially stressful situation.
If your horse does require a concentrate feed either to provide extra energy for work or to help maintain condition try to choose a feed that is high in fibre but low in starch and remember to feed small regular meals. Adding chaff to your horse’s feed will help to promote chewing and will extend the amount of time your horse take to eat, as well as providing extra fibre.
Try to minimise the amount of stress in your horse’s routine, for example allowing your horse to see others when stabled and reducing the workload if your horse is working particularly hard.
As the saying goes ‘prevention is better than cure’ and this particularly true for gastric ulcers, by following the guidelines above and making some positive changes to your horse’s routine you can help to prevent your horse suffering from gastric ulcers this winter.