The Latest on Ulcers
At the 2006 Holistic Veterinary Conference, Dr. Scott Carter gave a lecture on gastric and colonic ulcers. So much of the research has focused on gastric ulcers and their treatment but Dr. Carter also shared research on colonic ulcers. A study of the post-mortem findings in 500 horses revealed that 63% of performance horses had colonic ulcers.
We have come to understand many of the causes of gastric ulcers, such as infrequent feedings, high starch diets, and exercise causing the acid in the lower protected portion of the stomach to move into the upper, non protected portion. We also know the connection of non-steroidal anti-inflammatory drugs which decrease prostaglandin production and therefore decrease the production of protective mucous to line the intestinal walls. For gastric ulcers, treatments have been mostly focused on buffering the stomach acid or decreasing its production. Dr. Carter’s research indicates that while these treatments have been somewhat effective in treating and preventing stomach ulcers they have actually increased the imbalance in the rest of the digestive tract and in many cases been responsible for increasing the presence of colonic ulcers.
To understand what is happening we need to review the function of the stomach and small intestine in the digestive process. The glandular portion of the stomach in the horse produces acid on a continuous basis. It also produces digestive enzymes and mucous which protects it from the actions of the acid and digestive enzymes. The equine stomach is small and food does not normally stay in the stomach long before it is passed to the small intestine. The small intestine is also relatively short and food moves quickly to the large intestine where fermentation of fiber occurs.
The digestion of starch occurs in the stomach and small intestine by the actions of stomach acid and digestive enzymes produced in the stomach, and pancreatic enzymes released into the small intestine. Bacteria in the small intestine also contribute to the correct breakdown of starch. All of this starch digestion is highly dependant on the correct pH. The problem with the current treatments for ulcers is that the focus is on decreasing or buffering stomach acid which raises the pH in the stomach and small intestine. When the pH is raised to above four the digestive enzymes stop functioning and the population of healthy starch digesting bacteria in the small intestine decreases. Now undigested starch is moving into the small intestine with few beneficial bacteria. There is always a small number of harmful bacteria lurking about, without healthy bacteria to keep them in check and a higher pH environment, they thrive and they begin to ferment rather than digest the starch. The small intestine is not designed for fermentation and the harmful substances produced damage the intestinal lining producing ulcerations. The toxins produced by fermentation of starches greatly stress the liver when they are picked up by the blood vessels going from the intestines to the liver. Some of these toxins also find their way into the bloodstream directly through damage to the intestinal lining.
Now we have the remaining starch that was not digested or fermented being dumped into the cecum portion of the large intestine. The cecum is designed for the fermentation of fiber, not starch, and it also depends on pH for proper function. The lactic acid produced by the starch fermentation lowers the pH in the large intestine which kills the beneficial fiber fermenting bacteria and protozoa. Continued production of lactic acid and other harmful substances effectively shuts down fiber digestion and causes ulcerations and damage to the intestinal lining of the cecum and colon.
About the Author
Madalyn Ward, DVM, owns Bear Creek Veterinary Clinic in Austin, Texas. She is certified in Veterinary Homeopathy and Equine Osteopathy.
Memberships include American Veterinary Medical Association, American Association of Equine Practitioners, American Holistic Veterinary Medical Association, Texas Veterinary Medical Association and the Academy of Veterinary Homeopathy.
She has authored several books and publishes at her blog.