by Dr Catherine McGuigan MVB MANZCVSc (eq surg)
What is EGUS?
EGUS describes the erosion of the horse’s stomach lining, due to prolonged exposure to the acid produced by the stomach or a failure in the stomachs own mucus lining. It is a painful condition that should be very important to us as is can seriously affect our horse’s health and happiness.
Which horses are prone to gastric ulcers?
Any equine can be affected by this disease – recent studies have reported that 95% of racehorses, 93% of endurance horses, 37% of leisure horses, 63% of performance horses, and nearly 50% of foals were affected.
How do they occur?
Your horse’s digestive tract has evolved to accommodate a sedentary lifestyle, grazing fibre rich foods up to 16 hours a day. As a result, the average equine stomach constantly secretes acid approximately 30L/day independent of food intake.
When empty, the stomach is exposed to high concentrations of acid, buffered only by the bicarbonate in saliva. Reduced access to fibre greatly reduces saliva production.
1kg of hay = 3000 chewing movements = 4L of saliva
1kg of grain =1000 chewing movements = 2L of saliva
The combination of increased acid concentrations, an empty stomach and decreased buffering from saliva all allow acid digestion of the unprotected regions of your horse’s stomach lining.
What Puts Your Horse At Risk?
Studies have identified there are certain risk factors which may predispose your horse to EGUS. They include: an empty stomach; stress – weaning, transport, social stress; work – exercise reduces blood flow to stomach lining and causes gastric compression; illness – particularly musculoskeletal pain; nsaids – bute, flunixin – inhibit prostaglandins which interrupt blood flow to the stomach lining and decrease mucus production; windsucking.
What clinical signs might affected horse’s exhibit?
Clinical signs related to gastric ulcers can be vague and poorly correlate to the severity of the disease. Some horses will be obviously grumpy or have an appetite change. Other horses can be just as affected yet show very subtle signs such as a decrease in performance.
- A reduction or change in appetite. From eating well but a little slower, having multiple drinks during a feed, or preferring grass only and going off coarser hay.
- Poor body condition despite a good appetite often with a poor dull or rough looking coat
- Girthiness or disgruntlement at tacking up or grooming especially under the abdomen and girth area.
- A behaviour change – horses may become ‘less pleasant’ and owners frequently describe them as grumpy with them and other horses.
- A drop in performance – horses may have subtle changes such as a change in their canter transition or a slower race, to stopping or even bucking and rearing.
- Colic – Mild recurrent colic symptoms which can potentially lead to more serious manifestations such as gastric reflux and eventually perforation
- Stretching Out – this is a colic symptom in itself however owners frequently interpret this as urinary pain and can be seen with gastric pain
- Teeth Grinding – Especially seen in foals and is often a sign of gastric pain
- Diarrhoea – A small number of horses will exhibit intermittent loose stools
- ‘Just not right’ – most owners know their horses extremely well. When you feel something is just off, EGUS is always on our list of differentials.
Gastroscopy is the only definitive way to accurately diagnose EGUS. Clinical signs and faecal tests are not reliable. A gastroscope is carried out at the clinic with the horse sedated and in a crush. The whole procedure takes approximately 10 minutes and videos and images are recorded.
Gastroscopy requires fasting for 12 hours and removal of water for 4-6 hours prior to the procedure. For this reason many clients elect to leave the horse at Murray Vets the night before and the procedure is carried out first thing in the morning.
Treatment and Prevention
Omeprazole has been repeatedly scientifically proven to be a superior to treatment for EGUS than all other products on the market. Following gastroscopy, your vet will prescribe a suitable course of treatment often including omeprazole. Gastric ulcers if present must receive treatment as management changes will rarely actively treat the ulcers.
Changes in management are useful for prevention of recurrence and may include: grass or ad lib hay (fibre); frequent small meals; low carbohydrate feed; corn oil; social interaction; management of pain and concurrent disease.
Assessing response to Treatment
You are the best indicator that treatment is successful and most owners report a horse that looks feels, behaves and performs better.
A repeat gastroscope is recommended usually 30 days after the first to check the stomach lining has healed and the horse can safely discontinue medication.
To book a gastroscope appointment with Murray Veterinary Services Click Here or phone 08 95303751
