There is one thing about the topic of equine gastric ulcers that I am clear on – the more I learn about it, the more I realize we do not know. Most of the studies that have been done have been to show the effectiveness of omeprazole, an effective drug for curing and preventing ulcers. For a horse with severe ulcers, omeprazole does work extremely well and should be used as a treatment. However, there are downsides; daily treatment with omeprazole is not only expensive, but there are a lot of other questions that arise with its use, such as when or not a horse receiving omeprazole daily is in violation of the AERC Drug Policy if you stop giving it within 24 hours of a ride.
Omeprazole works by stopping stomach acid – an important function of the stomach that aids in destroying bacteria that could cause intestinal tract infections such as salmonella. The altered pH of the stomach may not kill viruses and fungi. Stomach acid is necessary to digest protein. The undigested protein moves through the cecum and large bowel, where fermentation can cause bloating, discomfort and foul smelling manure. Prolonged acid suppression in humans causes vitamin B12 mal-absorption. Further human studies have shown an increase in acid production following treatment. Omeprazole has been shown to significantly delay gastric emptying in humans, and there are several other potentially serious side effects that have been documented in humans, rats, and dogs (1). Long-term use in rats has shown thickening of the stomach lining which may or may not predispose for gastric cancer.
Even if we use the drug to cure our horses' ulcers, but do not change any of the management issues that are causing the ulcers – we could face the possibility of having to maintain our horses on omeprazole daily for the life of the horse while it is competitiveness, or possibly having to retire the horse from competition. It is especially important for us to learn the best way to manage our horses so that we can help them with the problem of ulcers.
Causes of Ulcers
o Extended periods (8-10 hours) with no food
o Progressively increasing workload
o Stress. Which can include a variety of factors – confinement in a stall, trailering, traveling to new places, changes in feed, etc.
o High grain diets
o Corticosteroid therapy
o Anti-inflammatory drugs (such as phenylbutazone ('Bute') or flunixin meglumine (Banamine)
o Horses suffering from diarrhea are at increased risk
o Being a horse!
Symptoms of Ulcers (any of the following)
o Low grade colic
o Poor appetite, including the horse refusing foods or supplements that were previously consumed before
o Slow eating, sometimes walking away without finishing meals all at once
o Belching noises
o Decreased performance
o Gradual loss of body condition
o Weight loss
o Pot belly appearance
o Teeth grinding, salivation, froth around the lips
o Lying on their back for prolonged periods
Functional Considerations of the stomach
Adult horses secret up to 7 or 8 gallons of gastric acid per day, or more than 6 cups per hour. This is continuous, independent of feed intake and the reason for stomach ulcers. One major cause of gastric ulcers in horses is prolonged exposure of the stomach to high acid levels. The equine stomach is designed for constant feed intake, which provides something for the acid to work on there before using up the acid.
The stomach of the horse is very small and makes up only 10% of the capacity of the digestive system. The upper compartment of the stomach is lined with a nonglandular squamous mucosa that is similar to that lining the oesophagus. 80% of equine gastric ulcers occur in this compartment, primarily because it has limited intrinsic resistance to hydrochloric acid and pepsin.
The lower compartment is lined with glandular and mucus-secreting tissue. Only 20% of equine gastric ulcers occurs in this compartment of the stomach because of its many intrinsic protective properties.
Emptying of the stomach takes 30 minutes for a liquid meal, while complete emptying after a hay-meal can take up to 24 hours. When a horse grazes all day, the roughage he consumes absorbs a reasonable 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.
Colonic Ulcers Significant Risk for Performance Horses.
In a study conducted by Frank Pellegrini, DVM, 63% of horses involved in competition sports – ranged from dressage to racing – suffered from colonic ulceration.
Pellegrini's work confirmed the findings of earlier studies, showing that 87% of horses have gastric ulcers (ulcers of the stomach). When combined with his findings on the less-understood issue of colonic ulcers, however, Pellegrini's study yielded some new information. He found that 54% of performance horses suffered from both gastric and colonic ulcers. Further, Pellegrini's study showed that 97% of performance horses had some type of ulceration.
"This research suggests that ulceration in the colon may be to blame for the low grade anemia, colic and other conditions seen frequently in high performance horses," said Pellegrini. "Most importantly, it brings into focus the need for further research on the direct causes of colonic ulcers and how exactly they affect the horse."
Pellegrini's research proves that colonic ulcers exist prevently within the performance horse population. Unfortunately, no treatment now available can cure them. Omeprazole, used for gastric ulcers, was formulated for the specific conditions found within the stomach and will not positively affect the delicate colonic environment.
"Given that more than 60 percent of all performance horses may be suffering from colonic ulceration – which can not be treated with traditional ulcer medicines – it may be time for equine caregivers to consider other options," said Pellegrini. "A dietary supplement intended to maintain optimum digestive health health may be the best solution to preventing colonic ulcers before they negatively affect performance and attitude in the horse."
One approach to promoting overall digestive tract health involves the use of non-testable, natural foodstuffs to heal the intestinal tract and support good health through this critical system. Here is a quick summary of some substances and how they may work to help keep the horse's gut healthy:
o Beta glucan is a dietary fiber found in oats and barley that has been shown to slow down the movement of feed through the gut, allowing excess starches to be digested before they enter the colon. Beta glucan is also a powerful immune stimulant, encouraging the horse's immune system to attack any bacterium that might otherwise enter an ulcer.
o Polar lipids are found in specially processed oat oil. Lipids (or fats) help to protect the lining of the gut. Polar lipids are emulsifiers ¬ they help water and oil to mix, and there before allow certain oil-soluble vitamins, such as A, D, E and K, to be absorbed by the gut.
o Glutamine is a natural amino acid that may help the gut renew and heal itself. It is "essentially essential," ¬meaning that the body can not produce enough of this amino acid when it is undergoing stressful situations, such as heavy competition training. Glutamine assays the cells of the gut to grow close together, keeping out dangerous micro-organisms.
o Threonine is another amino acid. It is "essential," ¬meaning that the body does not produce enough on its own, so it must be supplied in the feed. Threonine is needed for the creation of mucus, which lines the stomach and intestines, protecting them from acidic digestive juices.
o Yeast sugars called mannan oligosaccharides (or MOS, for short) help the immune system to get rid of bad bacteria. MOS also absorb dangerous toxins so they can be safely excreted. (Pellegrini, Franklin L. 2005)
Prevention and Recommendations.
o Respect the function of the gut!
o Turn horses out as much as possible so they can graze
o Do not feed a lot of grain
o If grain must be fed in large amounts, division feedings so that no more than three pounds is given at any one time.
o Avoid prolonged periods of fasting – ulcers can develop within 10-12 hours when horses have no access to feed
o Keep roughage available at all times. Horses need to eat continuously
o Provide free choice grass hay at all times
o Feed frequent small meals – optimum is 4 times a day
o Place feed bins on the ground – horses chew and swallow more efficiently when their heads are down and the throat extended
o Use steam-extruded feeds which have been processed in such a way that eating is slower, resulting in more chewing, increased saliva production and higher saliva bicarbonate levels
o Match your horse with a job he enjoys and is well suited for
o Gradually increase training schedule
o Ride conservatively until you know your horse handles competition
o Provide as much exercise and entertainment as possible.
o Provide Probiotics on a daily basis if your horse is in training or bound due to injury or illness
o Avoid frequent or long-term use of non-steroidal anti-inflammatory agents
o Tapeworm infestation can mimic symptoms of ulcers. Be sure to worm with a wormer that gets rid of tapes
o Add c cup of corn oil to your horses diet daily
o Bananas are a high energy feed and they also contain high levels of phospholipids that can assist in lining the horse's stomach and preventing acid damage to the stomach
o Papayas are another natural way to help horses with ulcers. Papain stimulates the appetite, soothes membranes of the esophagus and stomach and quiets inflammatory bowel disorders. Raw papain is used medically for enzyme replacement in pancreatic insufficiency and has anti-microbial, anthelmintic and anti-ulceratial effects.
o Horse owners have reported anecdotally that a cup of aloe vera juice twice a day helped their horses ulcer symptoms go away
o Horses should be fed no less than 50% (and preferably> 70%) of their dry matter take as long dry hay or pasture
o Feed a small amount of alfalfa (2-3 pounds once or twice daily), the calcium may buffer stomach acid
o Keep your horse in good body weight and a good body condition score
o Check out other non-antacid type ulcer products:
All but the last 2 listed projects as well as Pellegrini's work above were done on other than endurance horses. When race horses were studied well over 90% had ulcers. The incidence of ulcers in Endurance horses is as low as 50%, probably because of the closer relationship between horse and care giver along with management practices that are shown to be less likely to cause ulcers.
Benefits of Corn Oil Supplementation. Ponies fed a free-choice hay diet for 5 weeks, which was followed by 5 weeks of the same diet supplemented with 45 mL of corn oil daily. The study concluded that corn oil supplementation may be an effective and inexpensive way to increase the protective properties of equine glandular gastric mucosa. (Cargile JL et al., 2004)
Effects of exercise on gastric volume and pH in the proximal portion of the stomach of horses. Increased intra-abdominal pressure during intestinal exercise in horses causing gastric compression, pushing acidic contents into the proximal, squamous-lined region of the stomach. Increased duration of acid exposure directly related to daily duration of exercise may be the reason that squamous lesions tend to develop or worsen when horses are in intensive training programs. (Lorenzo-Figueras M et al., 2003)
Prevalence of gastric ulcers in show horses. Gastric ulceration was detected in 58% of the horses. Horses with a nervous disposition were more likely to have ulceration than quiet or behavively normal horses. Horses with gastric ulceration had significantly lower RBC counts and hemoglobin concentrations than those without ulceration. (McClure SR et al., 1999)
Do age or sex matter? One study on 224 Standardbred racehorses in training concluded that although there was little association between age and prevalence of ulcers, there was an association between age and severity of ulcers. Most 2-year-old horses (57.7%) had an ulcer score of 0 or 1. In all other age groups, most (58% to 82.61%) of horses had an ulcer score of 2 or 3. Despite overall prevalence of ulceration was comparable among sex groups, the relative risk for gastric ulceration increased with age in castrated males, whereas it decreed in females and sexually intact males. (Rabuffo TS et al. 2002)
Gastric ulcers in Standardbred racehorses: prevalence, lesion description, and risk factors. The number of lesion sites (P Omeprazole is labeled for use for a maximum of 90 days in horses. We simply have no data on the consequences of long term use in horses. rugal hypertrophy and gastric carcinoid (ie, it is not normal not to produce gastric acid chronically) In elderly patients especially, the chronic use of omeprazole has some association with becoming infected with Clostridium difficile (changing the normal environment leading to colonization with a pathogenic There has not been sufficient use of omeprazole in a wide variety of horses nor long term use for any of us in veterinary medicine to make any associations like this for horses. I would not put horses on it for longer than 90 days without more data. Trisha Dowling, DVM