EGUS and how Omeprazole can help

Article Provided By:  Ryan Thompson
General Manager | HorsePreRace.com

Equine gastric ulcers syndrome (EGUS)  EGUS is a commonly seen as a cause for decreased performance in race horses and it has been shown in research that 75-90% of event and race horses have EGUS. While only up to 60% of other classifications of horses were found to have EGUS. Although the numbers are greatest with race horses, it is clear from these numbers that the risk of EGUS is a big concern to all types of horses.

Why would the rates of EGUS differ you may ask?

Well there are multiple factors involved as to why this is so, the biggest risk factors have been shown to be primarily stress and diet. Diet is a big factor in horse health and limiting risk of EGUS. The horse has evolved for its natural lifestyle where it would constantly eat varying amounts of roughage throughout the day and unlike some species that produce stomach acid mainly during meals, horses constantly secrete stomach acid throughout the day to help digest their food. When a horse is not getting frequent feedings, or is being given food that a majority of which is not of a type the horse has evolved for, PH levels can plummet and result in damage to the gastric mucosa which leads to ulcers.

The quality and type of food is a major EGUS risk factor. Diets high in grain and/or with infrequent feedings have been found to contribute to EGUS. A horse on a diet high in fiber and roughage leads to a fibrous mat of chewed food in the horse’s stomach that provides a barrier and helps prevent acid from getting to the squamous region of the stomach. The constant chewing and swallowing helps enhance the alkaline effects of the horse’s saliva, which acts as a buffer to acid buildup.  Oddly enough research has also noted; “The presence of sand in the colon appeared to have a protective effect against Equine Glandular Gastric Disease (EGGD)  (OR = 0.195, 95% CI 0.04-1.0, P=.051 for sand versus not having sand).” I am in no way suggesting you feed sand to horses, I just felt this was an interesting finding that may have some value some place and is worth a mention.

Research findings have shown that excessive use of non-steroidal anti-inflammatory drugs (NSAIDs) in a horse also rises its risk factor for EGUS. The use of NSAIDs has been shown to decrease the production of prostaglandins, which play a major role in the production of the protective mucus layer of the stomach.

Another very important risk factor to be aware of is work load and stressful events. The change in environment, stall confinement, heavy work load and illness play a big role in the risk of a horse developing EGUS and since exercise have been shown to increase gastric acid production; a combination of poor diet, stressful events and putting a heavy workload on a horse are all very serious things to take into account when dealing with horse performance and their health. One of these risk factors is bad enough but a combination of them is truly asking for trouble and not fair to the horse as well of course. Just a good diet alone is not enough to prevent EGUS, in one study it was shown “Horses moved from pasture to strict stall confinement, for 7 days, developed ulceration of the squamous region of the stomach, despite having free-choice hay available”. Sometimes even just multiple handlers/riders might put the horse at a higher risk of developing EGUS and there has also been speculation on “potential pathophysiological mechanisms” leading to this condition as well. This isn’t too crazy of a thing to hear to me since we know people under a lot of stress (mental or physical) can develop ulcers even with a decent diet. Riders and breeders truly need to look at the whole picture when it comes to EGUS to truly help keep their equine companions healthy and in top performance.

 EGUS symptoms in a horse usually means pain, decreased appetite, weight loss, and behavioral changes. These symptoms don’t always show themselves in the same way horse to horse and more often than not when they do show it usually means it’s pretty bad and treatment should be looked into as soon as possible. Other symptoms may also include: Weight loss, poor body condition, poor hair coat, diarrhea and lying down more than normal.

The common treatments for EGUS usually involves the combination of a drugs and dietary changes. One of the main compounds used in the treatment of EGUS is Omeprazole. Omeprazole is “the only medication approved by the FDA for treatment (4 mg/kg/day, PO) or prevention (1 mg/kg/day, PO) of gastric ulcers in horses, and it has been shown to allow gastric ulcers to heal in horses that continue their normal training.” So there is good reason why it is one of the main compounds used with horses dealing with EGUS. Keeping the pH of the stomach >4 is usually the aim with Omeprazole use. Omeprazole is a proton pump inhibitor which decreases the secretion of gastric acid in the stomach and thus lowering the acidity of the stomach. Since the occurrence of EGUS is fairly common in race horses, so is the use of Omeprazole to treat it. Although I have already mentioned stress and diet as major factors in developing EGUS, it is also still very important to pay attention to diet even while treating EGUS not only for the health of the horse, but also for the effectiveness of Omeprazole. It has been shown in research that the “efficacy of Omeprazole in raising intragastric pH was good under the HG/LF conditions but relatively poor in the HAY diet. A cumulative effect of dosing, not previously reported in the horse, was observed. Both dose and diet may play a role in the efficacy of Omeprazole in the horse. Therefore, the use of singular dosing recommendations that encompass all horse types and management conditions may not be appropriate and dosing recommendations that take into account the diet of the horse may be advantageous.”

Omeprazole is seen by many as the best option available for treating ulcers in horses and although this is a well-known fact, the point of this article is to expand on this and to make note of other very important factors related to EGUS and Omeprazole use that some may not be aware of.

I hope this article helps you lay out the best course of action for your equine health and performance. We are proud at HorsePreRace to offer only the highest quality Omeprazole and equine related products for all of your equine needs!

horseprerace.com/omeprazole-paste-2-3gr

References 

1. Nadeau, J.A., F.M. Andrews, and A.G. Matthew. 2000. Evaluation of diet as a cause of gastric ulcers in horses. Am. J. Vet. Res. 61:784-790.  https://www.ncbi.nlm.nih.gov/pubmed/10895901
2. The effects of dose and diet on the pharmacodynamics of omeprazole in the horse- Sykes BW1, Underwood C2, Greer R2, McGowan CM3, Mills PC2. https://www.ncbi.nlm.nih.gov/pubmed/27554924
3. EQUINE GASTRIC ULCER SYNDROME by M-Th. Picavet http://www.ivis.org/proceedings/eenhc/2002/picavet.pdf?LA
4. (1999) Effects of orally administered enteric-coated omeprazole on gastric acid secretion in horses. AJVR, 60, 8, 929-931 https://www.ncbi.nlm.nih.gov/pubmed/10451198
5. Risk Factors for Equine Gastric Glandular Disease: A Case-Control Study in a Finnish Referral Hospital Population. Mönki J1, Hewetson M2, Virtala AM3 https://www.ncbi.nlm.nih.gov/pubmed/27461724
6. Murray MJ et al. (1996) Factors associated with gastric lesions in Thoroughbred racehorses. Equine vet J., 28, 368-374. https://www.ncbi.nlm.nih.gov/pubmed/8894534
7. Comparison of paste and suspension formulations of omeprazole in the healing of gastric ulcers in racehorses in active training. J. Am. Vet. Med. Assoc. 221:1139-1143 https://www.ncbi.nlm.nih.gov/pubmed/12387383