Since 2013, Professor Derek Knottenbelt and a team of researchers at the University of Glasgow, Scotland, have been studying gastrointestinal diseases in horses. Knottenbelt, an equine internal medicine specialist, is one of the most respected veterinary researchers and foremost experts worldwide.
While much research exists for understanding gastric ulcers, until now very little has been done to evaluate conditions beyond the horse’s stomach. The hindgut has been the primary subject of ongoing studies at the University of Glasgow. One of the key findings so far is that large colon pathology is significant in horses, supporting the idea that gastric ulcers aren’t the only common GI problem.
In this video, Professor Knottenbelt explains potential pitfalls of over-diagnosing gastric ulcers in horses and the treatment-oriented approach.
Watch the video to hear more from Professor Knottenbelt about this research and what his team has learned so far. [Warning: contains some graphic images.]
Here are some of the key points and highlights from the video.
Undue Emphasis on the Equine Stomach Because We Can See It
Professor Knottenbelt strongly suggests that the horse industry worldwide has placed undue emphasis on the equine stomach and gastric ulceration. The reason? We can see it with a gastric endoscope.
With the ability to view the horse’s stomach, “current studies have shown that 85-90% of horses maintained under existing circumstances are found to have clinically significant gastric ulceration,” Knottenbelt explains. “That’s alarming.” (In layman’s terms, “clinically significant” means that the condition has a real effect on daily life for the animal.)
The endoscope gave us a window into the horse’s stomach so we could see the extent of the damage and classify ulceration. And it has also given rise to an entire industry of therapy, diagnosis, repeat examinations and clinical research.
And in terms of the hindgut, Knottenbelt says, “Historically, we have not paid any attention further down because we can’t get at it.”
Why Does Equine Gastric Ulcer Syndrome Exist?
But while we now better understand and manage gastric ulcers, we have yet to eradicate or even slow this disease. And that’s a problem in terms of the horse.
“More importantly,” Knottenbelt says, “we need to understand why the syndrome exists.”
Many believe stomach acid is the cause of gastric ulceration in horses, but Knottenbelt calls that “very conjectural” and doesn’t agree. “There has to be something else involved. If gastric ulcers are attributed to acid, we have to ask why it’s there in the first place. Why does a horse standing there in a box develop extra secretory acid and a horse in the pasture doesn’t?”
Knottenbelt explains that the answer may lie with how the horse eats. In normal circumstances, the horse is ingesting short, chopped, rough fiber that requires lots of chewing. The more chewing, the more saliva is produced, which has a buffering effect on the stomach. Trickle fed, constant chewing equals a constant trickle of buffering saliva to protect the stomach.
The Downstream Effects of Long-Term Omeprazole Use
Omeprazole has become the gold standard for treating gastric ulcers and is used regularly in performance horses. But Knottenbelt questions whether this approach is best.
“The problem with long-term medication with omeprazole is that you restrict the amount of gastric acidity that is produced. And that is long-term drops and drops and drops and it is held at a very low level … But the argument is, ‘what is the downstream effect of it?’ Is there some consequence in terms of the digestive process? We have to understand that gastric acidity is a completely normal event for digestion.”
“I do believe that the likelihood is that horses that are maintained on omeprazole will have a downstream effect. Now exactly what reflects as is another matter. It could be in terms of the acidity or alkalinity of the ingesta, the food, that lands in the large colon as it trickles through…is the horse able to make as much use of the food as it otherwise would have done?”
We Must Shift Focus to Prevention and Welfare
Knottenbelt continues, “There’s an old adage that ‘prevention is better than cure,’ and that’s something we’ve forgotten in this syndrome… I believe that gastric ulceration is very heavily and very strongly over diagnosed and over complicated. We attribute far more to it than perhaps we should. There’s a commercial imperative to maintain the syndrome and no commercial imperative to prevent it.”
“We need to address those issues and we need to find fundamental ways of restoring the health of the gastrointestinal tract of the horse to something like normal given that it can’t ever possibly be completely normal, I suspect.”