Free Tool · Designed by Dr. Louise Cosgrove BVSc

Free Horse Ulcer Symptom Checker
& Gastric Ulcer Risk Assessment

Over 80% of performance horses have gastric ulcers — and many show only subtle signs. Assess your horse's risk across management factors, behavioural signs, and physical signs with our clinically-informed checker.

Takes 4 minutes
Covers ESGUS & EGGUS
Results emailed instantly
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Your Horse
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Management
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Behaviour
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Physical Signs
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Your Details
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Results

About your horse

Some horses are at significantly higher risk of gastric ulcers based on their type and use. Over 93% of racehorses have been found to have ulcers on gastroscopy.

80%
of performance horses have gastric ulcers on gastroscopy
93%
of racehorses in active training
37%
of pleasure horses — even at pasture

Management risk factors

Management practices are the biggest driver of ulcer risk. These questions assess how your horse's daily routine compares to evidence-based best practice.

e.g. transport, competition, change of property, change of paddock mates, illness, injury

Behavioural signs

Behavioural changes are often the first and most subtle sign of gastric ulcers. Tick any you have noticed in your horse.

Physical signs

These physical signs may indicate gastric ulcers or other gastrointestinal issues. Tick any you have noticed.

Your ulcer risk report is ready! 🩺

Enter your details to receive your personalised ulcer risk assessment and management guide by email.

Dr Louise Cosgrove equine veterinarian EEVS

Dr. Louise Cosgrove

BVSc, JP (qual) · Principal Veterinarian, EEVS

"Gastric ulcers are one of the most common and most under-diagnosed conditions I see in practice. The signs are often subtle — a horse that's 'just not right', a bit grumpy, or not performing as well as expected. If you're unsure, a gastroscopy is the only way to know for certain. Don't let your horse suffer in silence."

🩺 Your Ulcer Risk Assessment

Gastric Ulcer Risk Report

Based on your horse's management profile, behavioural signs, and physical signs.

📊 Risk Score

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💊 Recommendations

🏠 Management Changes

The Only Way to Know for Certain is Gastroscopy

Clinical signs alone cannot diagnose gastric ulcers. A gastroscopy takes approximately 30 minutes, requires 12–18 hours of fasting, and gives a definitive answer. Your local trusted equine veterinarian will grade the ulcers and design a personalised treatment and management plan.

🐴 Visit DIY Horse Vet 🌾 Check Nutrition
Educational Purposes Only — Important Disclaimer: The information and ulcer risk assessment provided by this tool are intended for general educational purposes only and do not constitute veterinary advice. This tool cannot diagnose equine gastric ulcer syndrome (EGUS). The only definitive diagnostic method is gastroscopy performed by a qualified equine veterinarian. This tool does not replace a professional veterinary consultation. Always consult a qualified equine veterinarian before commencing omeprazole or any other ulcer treatment. EEVS and Dr. Louise Cosgrove accept no liability for decisions made based on the output of this tool.

Equine Gastric Ulcer Syndrome (EGUS) — A Complete Guide

Equine Gastric Ulcer Syndrome (EGUS) is one of the most common conditions affecting horses in modern management systems. It refers to erosions or ulcerations of the stomach lining, and is now understood to encompass two distinct conditions with different causes, clinical presentations, and treatment approaches.

This guide, written by Dr. Louise Cosgrove of EEVS – Exclusively Equine Veterinary Services, explains everything horse owners need to know about gastric ulcers — from causes and signs to diagnosis, treatment, and prevention.

ESGUS vs EGGUS — Understanding the Difference

ESGUS — Squamous Ulcers

  • Affects the upper, non-glandular squamous region
  • No protective mucus layer — vulnerable to acid
  • Caused by acid splashing during exercise
  • Strongly linked to diet, exercise, and fasting
  • Responds well to omeprazole (28-day course)
  • Most common in racehorses and performance horses
  • Graded 0–4 on gastroscopy

EGGUS — Glandular Ulcers

  • Affects the lower glandular region
  • Has a protective mucus layer — but can break down
  • Associated with stress, NSAIDs, and Helicobacter-like organisms
  • More common in warmbloods and sport horses
  • Responds less reliably to omeprazole alone
  • Often requires sucralfate added to treatment
  • May require longer treatment course (56+ days)

The Ulcer Grading System

ESGUS — Squamous Gastric Ulcers

ESGUS squamous gastric ulcers are graded on a scale of 0 to 4 based on severity, as assessed during gastroscopy.

0
Normal — intact mucosa
1
Mild — reddening, no lesions
2
Moderate — small, single lesions
3
Severe — extensive lesions
4
Very severe — deep, bleeding ulcers

EGGUS — Glandular Gastric Ulcers

EGGUS uses its own severity classification, assessed during gastroscopy.

Mild
Slight reddening
Moderate
Lesions may be raised and numerous
Severe
Bleeding lesions

Prevalence of Ulcers in Horses

Horse TypePrevalence (ESGUS)Key Risk Factors
Racehorses in training~93%Intense exercise, high grain, fasting before work
Performance / Competition60–80%Exercise, transport, competition stress, grain feeding
Endurance horses~70%Long-distance exercise, electrolyte use, intermittent feeding
Pleasure horses~37%Intermittent feeding, stabling, low forage access
Broodmares~67%Late pregnancy, foaling stress, lactation
FoalsUp to 50%Stress, illness, interrupted nursing

Why Are Ulcers So Common?

The horse's stomach produces acid continuously — approximately 16 litres per day — regardless of whether food is present. In the wild, horses graze for 16–18 hours per day, keeping the stomach full of forage that physically buffers the acid and stimulates saliva production (which also buffers acid). Modern management practices disrupt this natural pattern in multiple ways: horses are stabled and fed twice daily, leaving the stomach empty for hours; large grain meals rapidly ferment to produce volatile fatty acids that damage the squamous mucosa; and intense exercise compresses the stomach, causing acid to splash onto the unprotected upper region.

Key Insight: The most effective single management change you can make to reduce ulcer risk is to ensure your horse always has access to forage — particularly before exercise. Feeding 1–2 kg of lucerne hay 30 minutes before exercise has been shown in multiple studies to significantly reduce the severity of exercise-induced squamous ulcers.

What Does Gastroscopy Involve?

Gastroscopy is the only definitive way to diagnose equine gastric ulcers. The procedure involves fasting the horse for 12–18 hours (to empty the stomach), then passing a 3-metre flexible video endoscope through the nostril, down the oesophagus, and into the stomach. The horse is lightly sedated. The entire procedure takes approximately 20–30 minutes. Dr. Cosgrove can visualise the oesophagus, stomach (both squamous and glandular regions), and the pylorus, grade any ulcers found, and design a personalised treatment plan on the spot.

Dr. Cosgrove's Tip: Don't wait until your horse is obviously unwell to consider gastroscopy. Many horses with Grade 3–4 ulcers show only subtle signs — a slight change in attitude, a reluctance to be girthed, or a marginal drop in performance. If something feels "off" with your horse, a gastroscopy is the quickest way to rule ulcers in or out.

Frequently Asked Questions About Horse Ulcers

Answers to the most common questions Australian horse owners ask about equine gastric ulcer syndrome.

What are the signs of ulcers in horses?
The signs of gastric ulcers in horses can be subtle and vary widely. Common signs include: poor appetite or reluctance to eat grain, weight loss or poor body condition, dull or rough coat, recurrent low-grade colic (especially after eating), girthiness or sensitivity when being saddled, reluctance to work or poor performance, changes in behaviour or attitude (grumpiness, aggression, or dullness), teeth grinding (bruxism), excessive salivation, and loose droppings. Many horses with confirmed ulcers on gastroscopy show no obvious clinical signs.
What is the difference between ESGUS and EGGUS?
ESGUS (Equine Squamous Gastric Ulcer Syndrome) affects the upper, non-glandular squamous region of the horse's stomach. This region has no protective mucus layer and is vulnerable to acid damage, particularly during exercise when acid splashes upward. EGGUS (Equine Glandular Gastric Ulcer Syndrome) affects the lower glandular region. EGGUS is associated with stress, NSAID use, and Helicobacter-like organisms, is more common in warmbloods and sport horses, and responds less reliably to omeprazole alone — sucralfate is often added to the treatment protocol.
How are horse ulcers diagnosed?
The only definitive way to diagnose equine gastric ulcers is gastroscopy — a procedure where a 3-metre flexible endoscope is passed through the horse's nostril, down the oesophagus, and into the stomach. The horse must be fasted for 12–18 hours beforehand. Gastroscopy allows the veterinarian to visualise the entire stomach lining, grade the severity of ulcers (Grade 0–4), and differentiate between ESGUS and EGGUS. Clinical signs alone are not reliable for diagnosing ulcers.
How are horse ulcers treated?
The primary treatment for ESGUS is omeprazole (a proton pump inhibitor), which reduces gastric acid production. The standard treatment course is omeprazole at 4 mg/kg orally once daily for 28 days. For EGGUS, omeprazole alone is often insufficient — sucralfate (a mucosal protectant) is commonly added, and some horses require a longer treatment course. Management changes are essential alongside medication: providing ad lib hay access, reducing grain intake, feeding lucerne hay before exercise, reducing stress, and minimising NSAID use. Without management changes, ulcers will recur after treatment is stopped.
Can you prevent horse ulcers?
Yes, many cases of equine gastric ulcers can be prevented through management changes. Key prevention strategies include: providing ad lib access to hay or pasture at all times; feeding a small amount of hay or lucerne 30 minutes before exercise; reducing grain intake and replacing with fibre-based energy sources; minimising stress; avoiding or minimising NSAID use; and using a prophylactic omeprazole protocol during periods of high risk such as transport, competition, or dietary change.
Does lucerne (alfalfa) help horse ulcers?
Yes. Lucerne (alfalfa) hay has been shown in multiple studies to have a buffering effect on gastric acid in horses, due to its high calcium and protein content. Feeding a small amount of lucerne hay (approximately 1–2 kg) before exercise has been shown to significantly reduce the severity of exercise-induced squamous ulcers. Lucerne is not a substitute for omeprazole treatment in horses with established ulcers, but it is an important component of both prevention and management.
How common are ulcers in horses?
Equine gastric ulcers are extremely common. Prevalence studies using gastroscopy have found ulcers in approximately 93% of racehorses in active training, 60–80% of performance and competition horses, 70% of endurance horses, and 37% of pleasure horses. Even horses in light work or at pasture can develop ulcers, with studies finding a prevalence of 11–51% in non-performance horses.
Dr Louise Cosgrove BVSc equine veterinarian EEVS

Written & Reviewed by Dr. Louise Cosgrove

BVSc, JP (qual) · Principal Equine Veterinarian, EEVS · Regency Downs, QLD

Dr. Louise Cosgrove has been working exclusively with horses since graduating from the University of Queensland. As the founder and principal veterinarian of Exclusively Equine Veterinary Services (EEVS), she performs gastroscopy regularly and has a particular interest in the diagnosis and management of equine gastric ulcer syndrome. She sees the impact of undiagnosed ulcers on horse welfare and performance every day, and is passionate about educating horse owners to recognise the signs early. This tool and its educational content have been designed and reviewed by Dr. Cosgrove to ensure accuracy and clinical relevance for Australian horse owners.

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