In Part 1 of we discussed the incredible preponderance of horses that have ulcers in their digestive tract. We also discussed the largely unrecognized but extensive performance limiting body/muscular-skeletal problems and “behavioral” problems that go hand in hand when horses have ulcers.

Since we have only some fifteen years ago, started recognizing that ulcers are a significant a problem, our knowledge is still limited. We are still learning and seeing the problem in more depth. What I, as a rider and clinician am now recognizing is that through the years we have unknowingly condemned hundreds of thousands of horses to the “trash heap. We simply had not known that so many “hard keeping hoses,” “bad disposition horses”, “poor performing horses” were suffering from gastrointestinal tract ulcers. Looking back, some dispositional issues were so severe that afflicted horses could be dangerous to handle and show severe aggression. Many of these horses could have been top horses if we had simply known how diagnose and how to deal with ulcers.

The sad truth is that with what we do know at this point is that many – many horses are still being condemned for these very same reasons. Because of a lack of knowledge about ulcers they are being relegated as failures as performance horses or just too difficult to work with. In my practice, I, daily, see horses that were normally mellow and easy to work with become nervous or agitated or even become downright aggressive.

So now let us talk about dealing with GI ulcers. (In all of the following discussion, I am going to refer to the horse as “he” or “him” with the readers understanding that I am referring to both genders in all instances.)

The first thing that must be acknowledged, like it or not, is that equine ulcers are a man made disease. We have taken a nomadic herbivore evolved to graze as much 20 hours a day (often on low quality forage) and placed him in confinement and bulked him up with “high quality” hay and massive quantities of grain that he would never have seen in his more natural state.

The “high quality forage” that we feed is really designed to fatten cattle or increase milk production and not the “lower quality” of forage that nature designed the horse to eat. This so-called “lower quality” may in fact be of more quality for equids needs! Perhaps we should answer the question, “Are we feeding the horse to eat or produce more milk?” Adding insult to injury, we don’t even allow the horse to eat and cover some distance over the 18 – 20 hour grazing period for which nature designed him. Instead we add to his stress by confining him to a stall or small area and feed him twice, or if he is lucky and we are good managers, we feed three times a day. Often he is alone, or out of sight of his companions – totally against his nature as a herd animal.

But we are not through yet. We transport him to strange locations, often over long distances, often without the companionship of horses that he knows, change the water that he is used to, perhaps change the forage he has at home and again confine him in a very small box stall, or tie him to a trailer for long hours at a time.

I am not so naïve as to suggest that we are going to suddenly change everything in our management and use of the horse. That is a fact of life and so are the consequent ulcers. However, it is possible with common sense to find ways to mitigate the environmental stresses, feeding, and many management aspects.

So, our next need is to understand a bit of anatomy with regard to the horse’s digestive tract and a bit of the physiology of how horses digest food. This will help us with common sense answers to what we have stated above. It will also help us to understand what types of medicines and nutritional factors we can use to treat ulcers and prevent recurrences.

Lets start with the horse’s digestive tract. If it were to be stretched out to its full length, it would be a full city block long. The stomach portion is one of the smallest aspects and can only hold two or three gallons of material at a given time. This means that with the large amount of food a horse consumes in a day, the stomach must pretty rapidly process the food and move it on into the small intestine and from there into the large bowels. So – in relationship to stomach ulcers – the key point is that the stomach is geared to eating small amounts on a nearly continuous basis and not large amounts two or three times a day. The horse evolved as a grazing animal, right?

Add to this the fact that the glandular portion (in the lower part) of the stomach secretes well over a quart and a half of hydrochloric acid every hour on a 24/7 basis whether food is present or not. If no food is present for long periods, the acid can literally start digesting the lining of the stomach itself. This phenomenon is even more likely to occur with exercise. During exercise, the tightening abdominal muscles compress the stomach and move acid up where it does not belong.  Especially during a canter or gallop, the viscera are propelled forward, essentially slamming into the stomach and compressing it against the diaphragm. The result is “splashing” of the acids (hydrochloric, volatile fatty acids and bile acids) up and onto the upper part of the stomach.

The lower part of the stomach, in addition to producing the acid, receives protection by also producing mucous. The upper or non-glandular part has no protection and thus is more susceptible to damage by the acids. The upper portion has squamous epithelium – not dissimilar in a way to our skin and you are aware of the effect of acid on our skin.

Add grain to the horse’s diet and we compound the acid load problem because grain digestion, as it starts in the stomach, is broken down into “volatile fatty acids” and adds to the hydrochloric acid and bile acids already present. Grains empty from the stomach more quickly than forage materials and progress into the small intestine. The larger the grain portion, the quicker the emptying. Here the digestion is aided by enzymes that break down the starch and complex carbohydrates into simple forms that can be absorbed through the gut wall. However, if there are large amounts of grain consumed, it is not adequately processed in the small intestine. The transit time in the small bowel, like the stomach, at one and a half to two hours is relatively short.

That means that food; especially grain that is not fully digested between stomach and small intestine ends up in the huge vat called the cecum. The cecum is the first part of what is referred to as the hindgut. The balance of the hindgut is the large (ascending) colon, the small colon and the rectum and the anus. The cecum is where all the tough fibrous forage material is processed and is not well adapted to processing carbohydrates (grain). Digestion here is accomplished by trillions of “good” bacteria that break the tough fibers into useable volatile fatty acids that are then absorbed through the gut wall.

When grain gets to the hindgut the breakdown, (besides volatile fatty acids) produces gas and lactic acid. Lactic acid makes the hindgut more acid and creates and environment where the “good” bacteria die off and release endotoxins in the process. Endotoxins are poisons generated by the death of the bacteria. The good bacteria are then replaced by “bad” bacteria that can thrive in the more acid environment created by the lactic acid.  The “bad” bacteria damage the intestinal mucosa (lining) allowing the toxins to enter the bloodstream. It is common to see picky eating, leaving food, becoming agitated or grouchy. The discomfort can also start horses to cribbing, weaving or stall walking. Other signs and consequences are bouts of mild diarrhea and/or colic that can, of course, progress to more dire consequences.

Besides giving medications (I will address the use of ulcer medications in the third part of this series), what can we do to help? We obviously cannot take our performance horses and duplicate their natural environment. But, we can make valuable changes via our management procedures.

The more time the stomach has food within it, the more it will properly stimulate the gut and use that amazing amount of acid production for the digestive process. With that in mind, whether at home or on the road, keep him eating small amounts of food as frequently as possible. Hay bags with small openings such as the “Nibblnet” (see, or a device that will dispense small amounts at preset intervals are available (google “slow feeders for horses”). At home the ideal, of course, is free access to pasture or forage. For those horses who “pig out” one can always use a grazing muzzle that makes them work for every blade. Also instead of feeding a bunch of hay in one pile, scatter it allover the paddock so that he moves and picks and moves and picks.

For horses that are on timothy, orchard grass or other grass hays, consider feeding about 20 to 25 percent of the hay in the form of alfalfa. It is postulated from studies showing lower ulcer rates when on alfalfa, that the higher calcium content and higher protein can serve to help buffer acids. Alfalfa may also induce more saliva production that helps buffer acids and protects the squamous portion of the stomach. Grazing also produces more saliva that has a protective effect. Acid buffering bicarbonate is released in the saliva by the act of chewing. Adding beet pulp (soaked and not containing molasses and preferably not genetically modified beet pulp) can be very helpful to at risk horses. It will slow the emptying of the gut and that is a good thing. It goes without saying, whether hay or grain, make any feed changes gradually. Gut flora (bacteria) need time to adapt.

If you are feeding grain with beet pulp, the pulp/grain mix will slow the passage out of the stomach and to the small bowel. More complete conversion to volatile fatty acids will take place and allow better absorption of those volatile fatty acids from the small intestine. (Remember, you don’t want them to get to the cecum.) You can also slow the intake of grain by feeding it in a pan that contains a number of smooth rocks that makes the horse work for every little particle. Remember that grains that contain quite a bit of fiber are good. Oats, for example, with about 50% fiber via the hulls are a safer and less carbohydrate rich but still good energy rich source for the horse (80 – 90% percent pre-cecal starch digestibility).

You can replace some of the grain/concentrate needs by adding fats to the diet. An athletic fit horse can handle up to 10% of his energy intake with fats/oils such as corn oil, peanut oil, or the rice bran supplements that are rich in fat.

Turnout, even when not a lot of forage is available, creates significantly less risk of ulcers and colic than occurs in stalled horses. Stalls, though often a necessary evil, are still one of the worst concepts that we have forced upon our horses. Turnout – turnout – turnout as much as possible, and yes, – even with dressage horses! In turnout it is always best for the horse to at least be in sight of other horses. Avoid any turnout with horses that your horse doesn’t know.

When exercising horses it is good for food some roughage to be present in the stomach to help blunt the effects of acid getting pushed up and onto the unprotected squamous porting of the stomach. It cannot be emphasized enough times to do your best to feed small amounts frequently.

It is a fact that many show, competition and racehorses live on the “go” and are in the “fast lane.” So what else can we do? Think about it – some horses handle stress better than others. We tend to ride what we have, but given a choice we can select horses that are not afflicted with anxiety separation. We can try to select horses that handle many stressors better than others – such as being around new horses, horses that are less anxious in a stall, horses that trailer well. Regarding all of these factors, talent, of course, may of necessity govern our choice, so what else can we do to mitigate the ulcer risk. We can keep a partner around whether it’s another horse, a small pony, donkey or a goat. Some horses are happy with a cat, a dog, or even a chicken in their stall or trailer.

We can train horses from an early age to handle short and then progressively longer separations. They can learn to trailer quietly and to get used to the presence of strange horses, crowds and the hubbub of shows and events before actually competing. Take them to the bank, the grocery store or dry cleaners! Getting used to stress inducing conditions early is certainly easier than dealing with them once emotional patterns are set. Exposure, exposure, exposure! We can help by keeping food available via hay bags or nets even when trailering. Fill with relatively small amounts and frequently replenish the bag or net.

In my opinion, ulcers of the digestive tract are an extremely important factor that has deleterious effects on their health, well-being and ability to compete at their best. We can do much to mitigate the risks. For all we do, we must still recognize that ulcers in our horses will be a part of life and must be treated.

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