Diagnosing and Treating Gastric Ulcers

Of course, you’d never intentionally do anything to harm your horse, let alone give him an ulcer. Since the day he came into your life, you’ve carefully planned every step of his training, and now you’re both ready to move to the next level. A bit more grain in his diet probably is in order to help him meet the increased demands of more challenging work. And to protect those oh-so-vulnerable legs, you’ve made arrangements for him to spend less time outside in the pasture and more time safely inside in a stall. If all goes well, you’ll be attending a handful of shows in the months ahead. You’re excited by the prospect of putting your horse’s impressive attitude and emerging dressage skills to the test. Through careful training and conscientious care, you’ve laid a solid foundation for success.

Unwittingly, you also may have set him up for an ulcer.

The subject of a number of studies in recent years, equine ulcers may be more prevalent throughout the horse population than researchers and horse owners once believed. Long a problem associated with racehorses, the condition, technically known as equine gastric ulcer syndrome (EGUS), may affect between 30 and 40 percent of all dressage horses, says Michael J. Murray, DVM, professor and Adelaide C. Riggs Chair in Equine Medicine at the Marion duPont Scott Equine Medical Center in Leesburg, Virginia. Although several factors associated with a horse’s care and management have been linked to the development of ulcers, “Changes in eating behavior and changes in intensity of training are two of the biggest contributors that make a horse more susceptible to developing ulcers,” Murray says. Yet there are ways to avoid the problem without curtailing your horse’s dressage training or giving up your aspirations altogether, and the most effective option also is the simplest: “As long as there is grass to eat and horses are able to eat that grass, they shouldn’t develop ulcers.” Murray says. And the reason? It has to do with a horse’s ability to live like a horse.

The Anatomy of an Equine Ulcer

To understand why horses of all kinds develop ulcers, it’s helpful to first define just what an ulcer is. In horses, as well as in people, it’s a wound in the lining of the stomach caused by acid. In people, ulcers are associated with the bacterium known as Helicobacter pylori — which has not been identified in horses. Treatment involves taking an antibiotic to fight the bacterial infection as well as medication to suppress the secretion of digestive acid, most of which is produced when food is consumed.

In contrast, horses secrete acid even when they are not eating, and for the most part, their stomachs are designed to withstand the secretions. The lining on the top portion of the stomach (the nonglandular or squamous lining) has minimal protection. But the bottom portion, which resembles the lining of the human stomach, is glandular in structure and has elaborate means of withstanding acid secretions. A horse’s penchant for grazing is natural self-protection against ulcers. When a horse grazes all day, the roughage he consumes absorbs a considerable amount of digestive acid, keeping the level within the stomach low. In addition, a horse’s saliva has an acid-neutralizing effect. As a result, the amount of acid that accumulates in a horse’s stomach declines when he’s eating and increases when he’s not – sometimes to a potentially injurious level – which indicates how important grazing may be to a horse’s well-being.

Consider, too, the results of one study that Murray conducted: He examined the stomach linings of horses who had been living their lives as nature intended – turned out to pasture and allowed to graze round-the-clock – and found that most were normal. Then those same horses were moved to stalls and given free-choice hay. Within one week – sometimes in as short a time as 24 hours – some of the horses had developed ulcers of varying degrees.

“Problems arise when you bring a horse into stall confinement and then superimpose large quantities of concentrate – whether it be grain or pelleted feed,” Murray explains. “Grain or pelleted feed increases the level of a hormone known as gastrin, which is released by the stomach and acts as a stimulant for acid secretion. Then after eating his grain, the horse might stand for some time without eating hay, and all the while he is producing acid.”

A second significant contributor to the development of lesions in a horse’s stomach is the intensity of his training. For reasons not yet fully understood, a program that demands more of a horse may predispose him to ulcers. In fact, the results of treadmill studies have shown equine researchers that the occurrence of ulcers increased as horses’ levels of exercise increased.

“Therefore,” Murray continues, “it is our management of horses – the way we feed, train and trailer them, and how we confine them to stalls – that causes the lining in the top part of the stomach to be exposed to acid more and more. Because this part of the equine stomach is very sensitive to acid, wounds or ulcers form.”

Nevertheless, it is entirely possible that a horse accustomed to living in a stall – because he’s done so all his life – will do better than a horse suddenly brought in from the pasture and subjected to what’s likely a radical lifestyle change. Those that reside in a stall from day one may be better at satisfying their natural urge to graze simply by spending more time at the hay net.

In addition, a horse whose routine remains relatively consistent from day to day probably isn’t going to have problems with ulcers. “Certainly the prevalence is not as high as, in say, racehorses or horses engaged in extensive showing where the normal feeding behavior and pattern are different,” says Murray.

Suspecting An Ulcer

“Because horses can’t tell us how they’re feeling, it’s hard to tell if a horse has ulcers or how severe they are,” Murray explains. As a result, diagnosing equine ulcers can be tricky. “There are often subtle signs that are easy to misinterpret,” he ays. “Things like attitude changes in your horse – maybe he’s a little lethargic or showing heightened nervousness – could be an indication of discomfort from ulcers. Even something as small as a change in performance, where the horse does not seem quite as fluid or polished as normal, could point to ulcers.”

Although the signs that follow are indicative of many medical conditions – some more severe than ulcers, others less so – they can help you to recognize that your dressage horse’s health may not be up to par. Consider ulcers a possibility if your horse exhibits:

  • a change in attitude – Is your horse more nervous than usual or less willing to perform? Does he seem grouchy or “out of it” for no apparent reason?
  • poor appetite – Is he eating as much as he normally does for the amount of work he’s accomplishing? Is he leaving any of his feed uneaten?
  • colic – Is your horse showing signs of low-grade colic, a persistent mild discomfort that may cause him to turn his head toward his flank, lie down excessively, paw or fail to finish a meal?
  • decreased performance – Is your horse not as “fluid” as normal? Could his usually fine movement be described as below average?
  • a decline in body condition – Is your horse’s coat not quite as sleek and shiny as it once was? Does he look “unthrifty” or just plain poor?
  • weight loss – Has your horse dropped weight, up to but not more than 10 percent of his body weight?
  • dull – Is your horse generally lackluster and seemingly without energy?

An Ulcer Case Study

Learn how an ulcer affected Olympic dressage team alternate Kathleen Raine’s horse, Fidelia.

It was a combination of signs that caused Richard Markel, DVM, to suspect ulcers when Fidelia, the horse ridden by Olympic dressage team alternate Kathleen Raine, wasn’t performing up to par. In 1999, after winning the reserve championship at the Festival of Champions at the U.S. Equestrian Team headquarters in Gladstone, New Jersey, Fidelia (affectionately known as Fiddle) and Raine journeyed to Europe.

“It had been really hot in New Jersey, and the heat had affected Fiddle,” recalls Raine. “But the top five horses went on to Holland, so she endured about a 30-hour trip to England, and when she arrived there, she was treated for mild colic.” Fidelia’s colic returned and was treated two more times, and finally Raine placed a call to her veterinarian back in the United States.

Guessing at ulcers but unable to verify his diagnosis through an endoscopic examination, Markel arrived with a full course of medication. Within days, Fidelia improved, and she suffered no other bouts of colic while in Europe. However, once she arrived back in the United States, she started showing signs of being “off.” Again, Raine was concerned because Fidelia has always been known for giving her all at every opportunity, whenever asked.

“Fidelia is just as sweet a horse as you could find, and she became a grouch,” says Markell. “It was just so uncharacteristic of her. So we scoped her and saw healed lesions and some starting to recur. We immediately treated her again, and she is back to being a big pet.”

The Key to Ulcer Diagnosis

“The only way to tell if your horse has ulcers is to have him checked by a veterinarian with a three-meter endoscope that can get into the horse’s stomach,” says Murray. In this way the veterinarian can detect whether a horse does, indeed, have ulcers. He also can see how severe they are.

Prior to submitting to an endoscopic examination for ulcers, a horse will have his food withheld for about 12 hours, and he won’t be allowed to drink water for about six hours before the exam. Then the veterinarian will insert the flexible endoscope through the horse’s esophagus and into his stomach, where the veterinarian will view any ulcers.

“The treatment of ulcers is important because it is essential to use a treatment that will really work,” Murray says. “The best, and most useful treatment at the moment of EGUS is omeprazole, which is available under the brand name of Gastrogard for horses.” (For people, omeprazole is available under the trade name Prilosec.)

Within the body, omeprazole works by shutting down some of the stomach cells’ ability to produce large quantities of hydrochloric acid, thus giving an equine ulcer time to heal. In contrast, oral antacids like Maalox and Mylanta work to neutralize stomach acid that already has been produced.

A third type of medication, known as an H2 blocker, competes with the compound histamine, which is naturally secreted by body tissues, so that it cannot stimulate stomach cells to produce acid. H2 blockers include cimetidine (Tagamet), ranitidine (Zantac) and famotidine (Pepcid AC).

Murray chooses to use omeprazole for three reasons: First, it is the only treatment for EGUS currently approved by the Food and Drug Administration (FDA). Secondly, the drug shuts down acid secretion by knocking out the acid pumps, as opposed to competing with the stimulant. Third, omeprazole is easiest to administer than other drugs. A paste that comes in a tube, omeprazole is given once a day.

The Cost of Ulcer Treatment

Treating a horse the size of a warmblood costs about $40 to $60 a day, and a full course of the medication runs 28 days. Despite the higher cost – a total $1,120 to $1,680 – Murray says, “Most of our clients want to use omeprazole because the horse can stay in training, he heals quicker and is better sooner. Also, the product is convenient to use.”

In contrast, generic H2 blockers cost about $15 a day. They are given in large doses every six to eight hours, depending on the individual case.

In the past, one of the problems commonly experienced with H2 blockers was that many horses were being under-dosed. As a result, the medication was not effectively decreasing stomach acidity. In some cases, it was of no use at all.

“This is where the owner-placebo effect comes into play,” says Murray. In other words, the owner wanted the product to work, and so he or she felt that the product had worked.

Protecting Horses From Ulcers

Luckily, thre are ways to prevent horses from developing ulcers. Management is key. Murray suggests turning out horses as much as possible so they can graze. He also cautions against feeding too much grain, which not only can cause colic, but also sets the stage for ulcers since it increases the production of gastrin, the hormone that stimulates acid secretion. “Just like the kid who eats too many candy bars, the horse that eats too much grain will not be interested in his veggies,” Murray says. In other words, he’ll spend less time eating the hay or grass that’s beneficial to his digestive system.

Is there a diet horse owners can use to prevent equine ulcers?

“Diets in relation to ulcers are under a lot of investigation,” Murray replies.

“We don’t know that such a diet exists or if it is compatible with the rest of the digestive system of the horse. It might be years before we know the answers to these questions,” he says.

Nevertheless, if your horse is traveling a great deal to perform in a number of competitions and he’s likely to be subjected to stressful conditions, it might be worth considering medical intervention to keep him from developing ulcers. When used as a preventative, omeprazole is administered in half the normal treatment dose. It’s a tactic that is being adopted by some upper-level riders and trainers. For example, after undergoing colic surgery in Florida, Grandeur, the horse ridden by Steffan Peters, received omeprazole as a preventative. “We never had him scoped,” says Allyson Rogers, Peters’ assistant, “but it just made sense after the colilc to offer it during stressful situations such as travel.”

Some horses handle a change in routine perfectly well and show no signs of stress or discomfort, and others react in a range of ways with various levels of discomfort. Unfortunately, there are no blood tests to reveal whether a horse has ulcers or to what extent. If ulcers are diagnosed and medication prescribed, a horse usually improves within two to three days. Most of the time horses with EGUS are treated on an outpatient basis.

The big question, of course, is exactly what do horses with EGUS experience.

“We have to rely on our observation of symptoms,” says Murray, since there is no way to really know what sort of pain a horse with ulcers experiences. Fortunately, advances in medicine combined with new insights into the management of horses are offering relief for what ails the equine stomach.

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