A change is attitude
The prevalence of gastric ulcers in racehorses has been
well known for a number of years. Various studies across
the world have reported that 80 - 90 % of racehors-
es have ulcers. However, there is a high incidence in
other equine athletes. Studies have shown a 40 – 60 %
incidence in other equine sports disciplines. The term
Equine Gastric Ulcer Syndrome (EGUS) is used to de-
scribe this disease because of its complicated nature and
many different causes.
The horse is meant to be a continuous feeder – a “free
range trickle feeder” with constant grazing and walking
around in order to feed. The horses’ stomach is essen-
tially designed for this type of feeding; it has a relatively
small volume and constantly secretes acid, which is re-
quired as part of the digestive process of fibre. The stom-
ach is essentially divided into two sections - the top part
(where the oesophagus enters) includes a blind ending
pouch (the fundus) and has a non glandular lining. This
acts as a reservoir for ingesta. This lining is highly sen-
sitive to acid. The bottom part is the body and is lined by
glandular mucosa, which has protection against stomach
acid including buffers. The junction between these layers
is called the margo plicatus (Picture 1). The outflow of
the stomach is called the pylorus and leads into the duo-
denum (first part of the small intestine).
One of the more common locations for the formations of
gastric ulcers is in the top part of the stomach in the non
glandular layer, where there is little protection from the
acid secretions (Picture 2). It is thought that in the
performance horse that one contributing factor for ulcers
in this region is the “splashing effect” with changes in
abdominal pressure when being exercised, causing the
acid secretions to surge into the non protected area. The
feeding of high levels of carbohydrates may also allow
certain by products to penetrate and damage the cells in
this area. Once damaged, healing can be slow, so perpetu-
ation of gastric ulcers is likely to occur.
Another region that ulcers are found in is the pylorus
(Picture 3) in the glandular portion. Ulceration in this
region can cause a delay in stomach emptying and lead to
colic. Originally it was thought that this type of ulcer in
the glandular portion of the stomach was more prevalent
in foals, however in recent years with the availability of
3m endoscopes it has become apparent that they occur
in adult horses too and are in fact different to the non
glandular ulcers. There is still much to learn about these
types of ulcers and their management. We are certainly
identifying a number of cases in the performance horse.
The clinical signs of gastric ulcers can be variable and
non specific including:
• Poor appetite / picky eater
• Weight loss / poor condition
• Dullness
• Rough hair coat
• Low grade colic
• Intermittent diarrhoea
• Lack of performance / training issues
• Change in temperament – nervousness and aggression
• Stereotypical behaviour – crib biting, wind sucking
• Sensitive to touch – when girthing, grooming or rugging
The diagnosis of EGUS is based on the presence of clinical
signs and confirmation with endoscopy. The horse needs
to be starved for at least 12 hours to enable the whole
stomach to be visualised and the horse is sedated.
December• • 2018
30 • The Australian Quarter Horse Magazine • November • December
2018