News Page

2nd January 2005

Stomach Ulcers – a question for the New Year

News Page notes how the incidence of equine stomach ulcers has become a major topic since the advent of the endoscope.  We must ask: is this a long-standing phenomenon only brought to light through the benefit of technology – or is it a new disease expression brought about by the management of the horse today?  It’s not an idle question, nor one we can readily dismiss when considering existing knowledge.

The clinical benefit of technology is there to be seen, and the way it facilitates accurate diagnosis.  But, while we accept equine research suffers from poor funding, all new statistics need to be examined objectively so that useful conclusions can be drawn.  Post mortem material was always available from slaughtered animals and stomach ulcers were never seen as a clinical problem as recently as the Sixties and Seventies, even in racehorses.  Yet, while horses bleed (and die now) from stomach ulcers, it is inconceivable that a major disease incidence was missed through years when pathological material was so readily available.

If the incidence is as high as we are led to believe (up to 90% of racehorses, 60% of show horses – according to various sources), does this reflect a modern mismanagement of domesticated horses generally; or is it an unreal finding, based on poor selection, perhaps an inadequate numbers of cases?  If not the latter scenario, is it the natural consequence of intensive production methods?  Maybe a reflection of commercial influences on feeding styles and training regimes at variance with the requirements of the natural horse?

For those who have observed training attitudes in the past, certain more recent changes are worthy of note.  The advent of interval training, for example, has resulted in a widespread effort to increase workloads, to impose longer work periods and stiffer exercises.  In some yards, horses go from gallops to walker, then to the swimming pool and later, perhaps, to a treadmill, in the foolish belief this might benefit fitness, or make fit horses harder and have more endurance.

To accompany this, efforts are made to increase the performance benefits of feeding.  The traditional diet has gone from a simple grain-based mix to a complex of food sources that may (or may not) be beneficial.  We simply don’t know.  The incidence of ‘tying-up’ has increased (as with ulcers), also other expressions of dietary deficiency, malabsorption or imbalance.

We can ask: what is the incidence of ulcers in the wild, or in controlled feeding conditions where horses are fed simple diets, like hay and oats?  Significantly lower, it can be suggested.

The results of technology need to be more than simply diagnostic.  They should help us link cause and effect in order to aid prevention.  The problem with settling for treatment is the propensity for disease expressions to get worse when the cause is not removed.

Causes

The direct cause is erosion of the stomach wall by acid produced for food digestion.  Nature provides a natural system to prevent this, but ulceration occurs largely because of the need for managemental controls essential to the whole business of training. 

Nature’s horse is a trickle feeder, whose digestive system is geared to constant intake, broken only for alternating periods of travel and rest.  There is no way for it to find large quantities of high energy, high protein mixes in the wild.  It is unlikely to have the opportunity to overload with acid-stimulating materials that take too long to clear through to the small intestine.  These are what may be described as ‘ulcerogenic’ factors and we need to balance the benefits with the problems they create.

Our Reasons for Stabling Athletic Horses are:

1  To control the diet, balance intake with energy production in order to prevent unwanted weight increase and fat deposition, also excesssive gut fermentation.
From human, as well as animal, athletics, we    know fat is not compatible with performance.  Also, horses with excessivly bulky bowels blow hard and lose both endurance and speed.
2  To control the environment, prevent extreme temperature fluctuations, thereby protecting the natural defensive mechanisms, so avoiding infection.
3  To control exercise and prevent accidents to heavily fed horses when let loose.

Problems with that Control

Horses in intensive training are usually fed concentrates 2 – 4 times a day, bulk being limited to lighten the large bowel and fibre provided in the way of hay/haylage.  The consequence can be lengthy periods when a horse has nothing to eat – especially at night.  It is (hypothesised that) at this time the stomach acid level rises and ulceration may be precipitated. This is thought to be partly due to lack of saliva production – and its buffering effect.  It may, however, also be from physically overloading the stomach and creating excessively long retention of acid-generating food materials there.

Horses fed too much concentrate, be it high or low quality, tend to get performance as well as digestive problems and the development of ulcers may simply reflect an error of judgment rather than any weakness in the digestive system.

The Answer

The first step is to link cause and effect through effective research.  It need not be a hugely expensive exercise, but should be objective and rational.

If we have a new disease expression, and there have been several in the past thirty-odd years, we owe it to coming generations, as well as to the horse, to establish the causes so we may change our ideas and eliminate all.

For Owners

Feed simple diets of known, good quality constituents.  Do not overload the stomach with large concentrate feeds.  Remember, the more complex the mix the longer the retention time is likely to be.  Spread the forage element to reduce non-eating periods. Treatment is available in the way of omeprazole and other, less effective, antacids.  Speak to your vet if you have a clinical problem.

Peter Gray

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