Equine Gastric Ulcer Syndrome (EGUS)
'Gastric Ulcers' is an increasingly recognised term in the equine
industry but is this down to increased prevalence or simply greater awareness
and understanding? According to Richard Hepburn BVSc (Hons) CertEM (IntMed) Dip
ACVIM MRCVS, Specialist in Gastroenterology, neurology and intensive care at
B&W Equine Vets, the problem has been around for decades but due to lack of
awareness and high cost diagnostic tools in the 90's and early 2000's, testing
and therefore identification of gastric ulcers was limited, until recently. Now
the disease is diagnosed as frequently as 1 in 3 horses with a much higher
likelihood in racehorses than sport horses1,2. In today's blog, we
break down the condition into need-to-know nuggets and look at how the
development of ulcers can be prevented.
What are Gastric Ulcers?
Gastric
Ulcers refer to sore and inflamed areas of the equine stomach which have been
exposed to stomach acid over a prolonged period3. Like us, horses
produce acid to assist in the breakdown of food in the stomach, however, while we
are meal secreters and produce acid only during
eating, horses are continual acid secreters and therefore produce acid
continually, even when they are not eating. As a result, certain triggers lead
to an excess of acid in the stomach or gastrointestinal tract and cause erosion
of the stomach lining4. The
erosion can vary in severity and is usually quantified using a 4 point scoring
system3.
Types of Ulcers
The two
most common types of ulcer relate to the name of the sections in the stomach
where the ulcers are found; the glandular region and the non-glandular region
(squamous). In the squamous region, ulceration is created when the mucosa is
exposed to acid continually over a prolonged period (Equine Squamous Gastric
Disease -ESGD). This type is seen more in racehorses and believed to be caused
by the typical feeding and turnout practices of a racehorse in training. In the
glandular region, despite a protective lining to protect the walls from a
naturally lower pH as shown in the diagram below, ulceration can develop when
the lining becomes compromised and occurs more commonly in sport horses (Equine
Glandular Gastric Disease).5
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An image by Sharon Smith MSc SEBC (Reg) IEng BHSAPC in a write up from the European Society of Veterinary and Comparative Nutrition Congress. |
How do I know if my horse is
suffering from ulcers?
Clinical
signs of the syndrome are commonly recognised from the following:1-4
Colic,
Poor Appetite, Changes in coat, Abdominal Pain, Diarrhoea, Discomfort when
tacking up/rugging, Changes in behaviour, Weight loss, Teeth Grinding and Poor
Performance. However, not every horse fits this mould as stated by Richard
Hepburn in a #HorseHour podcast on ulcers. Sometimes,
signs of ulcers may simply be demonstrated by unusual behaviour for your horse
such as a change in pace of eating their hard feed, leaving some feed or
choosing hay or hard feed over the other.
Diagnosing Ulcers
Diagnosing
ulcers is a quick and painless procedure as it can be performed in as little as
five minutes and involves a small sedation to prevent the horse from being
nervous or reactive when the tube is inserted. Once inserted through the
nostril, air is pumped into the horse’s stomach to allow for clearer views of
the stomach and for images to be taken. Upon completion, the air is then taken
out and the tube removed.6
![]() |
A Gastroscopy being performed at Buckingham Equine Vets |
In some
instances, gastroscopy has been seen as controversial because it requires the
horse to fast for at least 12 hours prior to scoping to allow for an empty
stomach and ulcers to be seen. This in turn, allows acid to build up for a
longer than optimal period which itself, is a cause of ulcers. This can be
particularly conflicting as another gastroscopy is performed after a month of
treatment to ensure ulcers have healed. However, most veterinary practices try
to perform scoping in the morning so that the horse’s natural fasting period is
only extended by a few hours. Furthermore, although bad for gut health, 12 hour
fasting will only create ulcers after several days, not after one night6.
Suggestions for an alternative diagnostic
tool for ulcers have been attempted by Hewetson et al. (2017)7 who tested
blood sucrose levels. However, this did not prove accurate or specific enough.
Consequently gastroscopy is currently the sole diagnostic tool.
Treating Ulcers
There are a few options for treatment but this depends on the type of
ulcer. Quite often, the vet will prescribe an acid inhibitor called omeprazole
or an antacid or coating agent supplement. It is also recommended to feed 50ml
of corn oil, once or twice a day which has shown to reduce acid considerably in
the stomach after 6 weeks8.
There are several gastric supplements on the market to improve gut
health but these will only be effective for prevention and will not cure
ulcers.
Following treatment or to prevent ulcers, new management practices
should be deployed. These include:
- Managing forage provision. It has been found that horses eat predominantly between 7am and 11pm and therefore consume less forage in the night. Advice from vets state that 80% of a horse’s daily intake should be fed within the daytime and the remaining 20% overnight when the horse is resting and sleeping. Increased access to turnout also reduced the risk of ulcers.8
- Varying forage provision – Once the daily intake has been calculated and split between day and night, the ration should be split further between several haynets or feeding areas to allow the horse to move between them to keep fuller for longer. Free access to forage and reduced time between feeding (<6 hours) have widely reduced the risk of ulcers9.
- Feed prior to exercise – Despite old myths and teaching to never feed before riding, contemporary research suggests feeding the right forage before exercising the horse helps to soak up stomach acid, consequently preventing the ‘splash effect’ whereby acid build up moves and ‘splashes’ around the stomach as the horse exercises. In general, the horse’s stomach contains 2-4L of acid all the time so feeding chaff approximately 30 minutes before riding helps to trap the acid and protect the stomach for up 2-4 hours8.
- Similarly, feeding and watering after a ride will also help acid management. Unlike us when we exercise and blood moves from the stomach to the muscles, the horse’s blood supply to the stomach during exercise is maintained to sustain and even speed up gastric motility. Horses without access to water were considered 2.5 more times likely to develop ulcers9.
- Some alternatives/additions to medication such as the administration of Aloe Vera have been suggested but the efficacy is yet to be examined. For more information on Aloe Vera as a treatment, click here for the latest study.
- Where possible, avoid situations which cause your horse to become stressed as stress in both humans and horses have shown to increase stomach acid10,11
- Horses prone to colic are also at risk of ulcers with 83% of colic cases diagnosed with ulcers in a study by Murray et al. (1992)11. If your horse is prone to colic, perhaps look at putting some preventative measures in place.
Further Listening / Reading
![]() |
Gastric Ulcers Explained: Richard Hepburn Podcast |
Trackener Life kits enable monitoring of stress and detect the early signs of health conditions such as colic and ulcers. For more information and to order one for your horse click here.
Written by Ruth Box @ruth_box6910 Email Ruth
References
2BETA (2015) Market Information http://www.beta-uk.org/pages/industry-information/market-information.php
3Murray MJ, Eichorn ES. Effects of
intermittent feed deprivation, intermittent feed deprivation with ranitidine
administration, and stall confinement with ad libitum access to hay on gastric
ulceration in horses. Am J Vet Res 1996; 57:
1599-1603.
4Sykes BW et al. Rethinking equine
gastric ulcer syndrome: Part 1 – Terminology, clinical signs and diagnosis.
Equine Vet Educ 2014;26(10):543-547.
6Horse Hour (2016). [podcast] Gastric Ulcers
Explained: Richard Hepburn. Available at https://www.acast.com/horsehour/gastriculcersexplained-richardhepburn
[Accessed 29 Nov 2017].
, Risk factors associated with
equine gastric ulceration syndrome (EGUS) in 201 horses in Denmark. Equine Vet J 2009;41:625–630. , , .
. Gastric ulceration in horses:
91 cases (1987–1990). J Am Vet Med Assoc1992;201:117–120.
Super post! I don't think people always understand that a change in lifestyle is the most effective way to prevent ulcers. As someone with an ulcer-prone horse, I'm giving this post a big thumbs-up!
ReplyDeleteI like that you mention that there are many things on the market to prevent, but not treat ulcers. This is so true, and people really do need to engage their vet if ulcers are suspected. I think many horses suffer needlessly as owners try to find either a "natural" or a "cheap" way to treat them.
I prevent ulcers in my mare by giving her a good probiotic daily, along with a product from Omega Alpha called Gastra-FX, which coats her tummy. But when I suspect a flare up, I immediately start a round of Gastrogard. It's the only thing that truly works (although my vet and I have found that we can treat with a smaller dose than the maker recommends - we usually only dose with half a tube a day rather than a full tube and find the results to be the same as with a full tube - this is helpful as it is a very expensive medication for sure.
Thanks again for the super post!!!
Thank you for your lovely long comment and feedback Pam! Prevention is always better than cure to keep our horses happy and healthy but unfortunately sometimes things are beyond our control in the more anxious horses. I'm really glad you've found a solution and formulated a routine to help keep your mare happy and thank you for sharing what works for you. Every horse is unique and so it's great to find a system that works for them. Good luck with keeping them at bay!
DeleteThis was a very interesting read. I did not know anything about horse stomachs and ulcers. Thank you for this article!
ReplyDeleteHi Amy, thank you for your feedback. I'm glad it helped you!
DeleteHaving worked with Racehorses for years, I have seen many miracles when ulcer treatment begins. I treated behavioral issues, such as stall walking, ill temper with gastro guard, or dosing ranitadine three times a day, it is effective, just not easy. This is very informative, and did not know that horses do not need as much at night. Makes sense.
ReplyDeleteThanks
Hello, thank you for sharing your experiences with ulcers. I am not surprised you have seen it a lot in the racing world, research shows it can be as high at 90% in racehorses! I'm glad you found it a worthwhile read.
Delete