Equine Gastric Ulceration Syndrome
Equine Gastric Ulceration Syndrome (EGUS)
Modern horse management often involves practices that are less than ideal for the complex
equine digestive system. Limited grazing on short pasture, excessive stabling, frequent
travelling & intensive exercise take their toll.
This is all in direct contravention to the horses normal trickle grazing requirements, which
keep the 24/7 hydrochloric acid production in the equine gut stabilised by the saliva
produced during the grazing process. Added to other factors such as treatment with non-
steroidal anti-inflammatory ’s such as bute or steroid therapy, chemical wormers and a
plethora of other gut stressors, the result can frequently be ulceration of the gastro
It is reported that 1 in 3 horses may have stomach ulcers & statistically this is 90% of all
racehorses in training, 70% of all performance horses or those in full work & 40% of so
called leisure horses, so those in infrequent work or even pasture ornaments!
Horses can also develop ulcers in their hindgut (small/large intestines/cecum). This
condition is commonly referred to as colonic ulcers or right dorsal colitis (RDC). In a recent
study of 545 horses tested for RDC, 44% of nonperformance horses and 65% of
performance horses had colonic ulcers. This type of ulceration is much harder to diagnose
as there is no definitive test/procedure available apart from limited ultrasound, so would
appear to be unrecognised by many owners/trainers & vets & consequently is greatly under
reported from my experience.
The hindgut is the largest & most important part of the equine digestive tract, & once these
negative changes start to take effect, the delicate ph level that supports the naturally
occurring bacteria & protozoa is altered. The plethora of symptoms that can follow may
affect the entire holistic balance, and the animals ability to live up to the owners
expectations & requirements.
I am frequently asked, in my capacity as a Laser Therapist/Acupuncturist/Herbalist, to look at & if possible help
horses with a variety of problems. These may be so called ‘behavioural’ or long standing training or muscular
skeletal issues that the owner has religiously tried to help. Often the owner has spent a great deal of time & money
on veterinary blood tests, scans, and pain relief followed by months of ‘physiotherapy’ with no change or an ever
changing plethora of additional symptoms & problems. As a qualified practitioner of Oriental Medicine I take in all of
the current & historical information followed by a comprehensive physical palpation examination of both body points
& pulses, & in many cases I am led to the conclusion that the horses in question are suffering from EGUS ( Equine
gastric ulceration syndrome), and may have been for many years. Once this is addressed the change in the horse
can be extremely dramatic & also very rewarding.
I hope that by writing this article & passing on some of the information I have accumulated from my experiences &
research I can save a lot more owners, trainers & horses from the frustration, pain and expense of this nasty but
Gastric and intestinal ulcers are literally a slow or non-healing acid burn - a burn such as if hydrochloric acid was
splashed on your face. The horse’s ulcers are a combination of this hydrochloric acid, as well as volatile fatty acids
and bile acids. In horses, the acid erodes the lining of the stomach, small or large bowel. The acids may burn a
crater deeply enough to cause bleeding or even burn through and penetrate the gut. After healing scar tissue is
often produced, creating lesions, especially in the small intestine, that may lead to colic.
The Direct & Indirect Effects of Equine Gastric Ulceration Syndrome
1. An increased risk to the horse and riders health, safety and welfare
2. A loss of performance and competitive edge
3. Can be very expensive to treat and to resolve – recurrence is common
4. Cause many “behavioural” problems - often described as 'quirky'!!
5. Can set up many muscle, myofascial and skeletal issues
6 An increased risk of injury and lameness as a result of number 5 (Musculo- skeletal problems
7. An increased risk of colic and diarrhoea problems
8 Increased stress levels caused by constant pain may deplete the immune system and make a horse more
susceptible to diseases and allergies.
9. May create “hard keepers” and cause weight loss. The result – an un thrifty horse. (However, some horses with
excellent weight also suffer)
10. Toxins released from altered gut flora increase a risk of laminitis & foot abcesses.
11. Chronic sufferers are frequently anemic due to mal absorption of nutrients.
12. May produce headshaking symptoms, both seasonal or constant.
Some Typical Signs & Symptoms of Equine Gastric Ulceration Syndrome.
A horse suffering from ulcers may show very few outward signs – such is the nature of a prey animal that is designed
to hide any weakness from predators’. However if he is showing 3 + of any of the following, with or without any
obvious digestive issues, it may well be assumed that ulcers are or soon will be the culprit.
• Behavioural Issues
When ridden, the horse may become more resistant to going forward and responding to the normal aids. It may
kick out, rear or buck when asked to go forward. Commonly it may ‘banana’ away from the painful side (a horse with
left sided ulceration will bend right but avoid left bend behind the saddle). Many horses become very spooky in an
irrational manner & others, particularly in chronic cases “turn inward” and appear dull depressed and disinterested –
sort of “the light is on, but nobody is at home.”!
The skin is often very sensitive & the rugging process will produce aggressive or fearful behaviour. Plaiting or
pulling the mane may become very difficult & clipping impossible without sedation. In particular the chest & girth area
will be extremely reactive. The skin along the sides & flanks will often be very reactive causing extreme behaviour
when the leg is applied. Long term hindgut ulceration may lead to 'leaky gut syndrome' causing release of
endotoxins through the skin appearing as oozing hives or swellings. Vets will give mostly give steroids which will
exacerbate the problem.
Tacking up may show extreme reactions to the girth being tightened (due to the location of the painful large
intestine) or the saddle being put on. Because of the position of the equine stomach the wither pocket is often very
tender when stomach ulcers are present
Cribbing &/or wind sucking/teeth grinding – in my opinion & from
experience,this trait is always caused by pain of some sort. If not from
GIT ulceration then from teeth problems or possibly mesentery
lipomas. In any case this behaviour should always be thoroughly
investigated & not passed off as habit when pain management
is the problem.
Wood chewing is another sign of a problem, & can be either due
to vitamin/mineral deficiencies that the horse is trying to self correct
or the need to stimulate saliva production to neutralise excess acid,
when there is nothing else to eat.
Aggressive behaviour to others & around food is commonly seen & an indication that pain levels are high & the
craving for something to pacify the gnawing gut pain is needed.
Problems with bitting & acceptance of the contact may be
noticed in spite of the teeth seeming fine. Constant 'crunching'
on the bit may occur.
• Performance and Body Pain Issues
It is not commonly realised that ulcers go hand in hand with body pain & impaired performance. Whether arising
from muscles, skeletal problems or from joints, pain is inextricably associated. The form that the issue takes is, of
course, variable, but may include reluctance to jump as normal, running out, bucking or refusals. It is not uncommon
for the horse to buck after a jump. Similarly horses may be reluctant to go downhill.
Dressage horses, for example may refuse to take a specific lead or to perform a pirouette, halfpass, etc. In such
cases (including the horse landing after a jump), when the stomach has been compressed by the viscera (abdominal
contents) the acids in the stomach are splashed up and onto the non-glandular portion.
This portion of the stomach is more susceptible to acid damage than the glandular
portion (that portion secreting the acid.) 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. 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. 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.
Due to the consistent pain patterns found in EGUS cases, particularly hindgut issues, the horse may canter
disunited or refuse to strike off on a specific lead. Often these horses do not come through in the hindquarters
(especially the right hind). This is due to the placement of the large intestine which sits in the right dorsal quadrant
directly above the off hind. In some cases idiopathic right hind leg lameness is present in spite of there being no
damage to the leg itself.
Other consistent findings include soreness/pain in the thoraco-lumbar area (the transition zone from chest
vertebrae to the loin vertebrae). There is also a consistent pattern of pain and dysfunction in the sacroiliac.
Vertebral joint dysfunction is defined, basically, as an inability of joints to move through their full range of motion.
Loss of joint motion results in pain and tension with the inability to use the back properly.
One very important muscle that is frequently dysfunctional in ulcer cases is the Psoas (pronounced “SO-as and is
actually a group of 3 muscles). Taken together, this group represents one of the largest and strongest muscles in
the body. Its function is to stabilize and protect the pelvic girdle from damage.
The Psoas muscles are usually intimately involved in chronic sore backs in
both horses and people. When there is Psoas muscle pain the pelvis and
croup muscles cannot function well. The croup muscles then go into
spasm and are painful on palpation. Understanding this, it is easy to
visualize significant loss of performance ability.
Depending on how you manage your horse/lifestyle there are several ways of diagnosing ulcers ranging from
scoping to acupoint palpation. However none of these are totally definitive since scoping can only see into the
stomach, when the ulceration may be in the colon or hindgut. In a retrospective university autopsy study of 565
horses, 45% of non-performance horses and 65% of performance horses were found to have ulcers in the hind-gut
(specifically in the Right Dorsal Colon) but not in the stomach. These cannot be picked up by endoscopic
examination. This explains why one may recognise the symptoms and patterns described in this article in spite of a
negative endoscopy. Palpation of certain acupoints can provide some very accurate information about the horse &
as a qualified, experienced classical acupuncturist; I have found
that even the most subtle of signs can help with confirmation of
Of course any horse suffering with gastric
problems such as ulcers will benefit greatly
from the use of Laser Acupuncture Therapy.
Not only will it speed up the rate of healing but will
boost immune function & rebalance the energies
to help prevent re occurrence. By adding local
therapy to address skeletal, tendon & muscle
tensions you have the perfect adjunct treatment.
I also offer a digestive remedy comprised of a Chinese herbal formula used to treat similar human problems.
In many cases, herbal therapy alongside the
suggested protocols can help immensely & keep
the horse balanced & healthy.
Chronic Problem Management
Once your horse seems to be improving & symptoms are reducing then exercise is a very important factor in good
health. However a change in mind set is required if a re occurrence of the problem is to be avoided.
• NEVER work a horse on an empty stomach.
I hear you saying ‘but we have always been told to never work a horse after feeding’. Putting food into the stomach
prior to exercise will stimulate saliva production to neutralise acid & act as a buffer to prevent the splashing up of
acid onto the upper & most sensitive part. I feed half a scoop of Lucie nuts whilst the horse is being groomed/tacked
• Research the correct feeding regime for your horse.
I use a lot of lucerne & alfalfa which is proven to help as an acid buffer & I keep hard feeding to a minimum. I am not
a nutritionist so I’m not going to advise on this, but there are plenty of feed companies who will be happy to help you
with good advice. Do however avoid wheat products & added molasses.
• Keep stress to a minimum.
Stress is proven to increase EGUS so make sure you horse has a relaxed environment that makes him feel safe.
Keep all medications (chemical stress) to a minimum. If he needs chemical wormers then assume ulceration will
follow & treat accordingly for a week or so. The same goes for any other medications such as painkillers/ steroid
injections etc. which have very high risk rates attached for ulcers.
• Never assume that your horse will stay ulcer free forever.
Statistics show that re occurrence rates are high so be aware of any changes that may indicate problems. Always
keep a supply of ranitidine in the tack room & treat prophylactically before & after stressful events/management
• Always keep your vet advised of your suspicions/treatment protocols.
Even if you can’t afford or choose not to use the scoping & subsequent drugs that he may prescribe you need your
vet on side in case things escalate. Should colic ensue or your horse have black droppings (melena or old blood in
the stools) do not hesitate in getting veterinary advice or a call out.
If you would like to know more about my methods of diagnosis & treatment please feel free to contact me. I am
always happy to try & help.
Annabelle Knight TCM Equine.