How To Tell If Your Horse Has Ulcers: A Comprehensive Clinical Guide To EGUS Detection

Identifying Equine Gastric Ulcer Syndrome (EGUS) requires a multi-faceted approach combining behavioral observation, physical performance tracking, and gold-standard diagnostic gastroscopy. Recognizing subtle indicators such as "girthiness," recurrent low-grade colic, and a decline in body condition score (BCS) allows for early intervention and the prevention of mucosal perforation or chronic gastric scarring.

Diagnostic Preparation and Environmental Risk Assessment

Before pursuing clinical intervention, a horse owner or barn manager must establish a baseline of the horse’s environment and history. Equine Gastric Ulcer Syndrome is categorized into two distinct types: Equine Squamous Gastric Disease (ESGD) and Equine Glandular Gastric Disease (EGGDS). Understanding the difference is vital because their risk factors and treatment protocols differ significantly. While squamous ulcers often result from acid "splashing" during exercise or prolonged periods without forage, glandular ulcers are frequently associated with stress and the breakdown of the stomach's natural protective mucus layer.

To prepare for a veterinary consultation, you should compile a detailed dossier of the horse's current management.

• Behavioral and Performance Log: Document any resistance to the leg, tail swishing during transitions, or unusual aggression during grooming. Note if these behaviors correlate with feeding times or exercise intensity.
• Dietary Audit: Record the exact weight of forage (hay/pasture) consumed daily, the starch/sugar content of concentrates, and the frequency of feedings. Ulcers thrive in environments where the stomach remains empty for more than 4–6 hours.
• Medical History: Note any recent use of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) like Phenylbutazone (Bute) or Flunixin Meglumine (Banamine), as these can inhibit prostaglandin production, leading to glandular ulceration.
• Equipment Checklist for Diagnostics: If a gastroscopy is scheduled, the horse must be fasted for 12–16 hours and water-deprived for 2 hours. Ensure a clean, safe stocks area or a quiet stall is available for sedation and the procedure.

Clinical Protocol for Identifying Gastric Pathologies

Step 1: Evaluating Behavioral Markers and "Girthiness"

The first indication of gastric distress is often a change in temperament. Horses are prey animals and naturally hide pain, so "learned" behaviors are significant diagnostic clues. Pay close attention to "girthiness" or "cinchiness"—biting, pinning ears, or kicking out when the girth is tightened. This occurs because the pressure of the girth compresses the ribcage and pushes the stomach upward, causing acidic contents to come into contact with sensitive ulcerated tissue near the margo plicatus.

Pro-Tip: Observe your horse's eating habits specifically. A horse with ulcers may start a meal with enthusiasm but stop abruptly after a few bites (slowed consumption) or exhibit "wood chewing" and cribbing, which are often attempts to salivate and buffer gastric acid.

Step 2: Assessing Physical Condition and Coat Quality

A horse’s exterior often reflects its internal health. Conduct a weekly Body Condition Score (BCS) assessment using the Henneke 1-9 scale. A sudden drop in score, or a failure to gain weight despite high-calorie intake, is a hallmark of EGUS. Furthermore, look for a "staring" or dull coat. When the digestive tract is compromised, the absorption of essential fatty acids and fat-soluble vitamins is hindered, leading to a lack of coat bloom.

Warning: Do not confuse "poor doer" genetics with medical pathology. If a horse with traditionally high metabolism suddenly becomes picky about grain or develops a hay belly while losing topline muscle, clinical ulcers are the primary suspect.

Step 3: Monitoring Performance and Under-Saddle Resistance

For performance horses, the most telling sign is a "loss of spark" or unexplained resistance. This often manifests as a refusal to jump, difficulty with lead changes, or a general "sour" attitude toward work. In high-intensity exercise, the abdominal muscles contract, increasing intra-abdominal pressure and pushing gastric acid from the glandular lower region into the unprotected squamous upper region. This is known as the "acid splash" effect. If your horse performs well initially but becomes increasingly agitated or reluctant as the session progresses, the stomach is likely the source of discomfort.

Step 4: Diagnostic Confirmation via Video Gastroscopy

While behavioral signs provide a strong suspicion, a definitive diagnosis can only be achieved through gastroscopy. This involves passing a 3-meter flexible endoscope through the nasal passage, down the esophagus, and into the stomach. This allows the veterinarian to visualize the squamous mucosa, the glandular mucosa, and the margo plicatus (the interface between the two).

During the scope, the veterinarian will utilize the Lund Scoring System to grade the severity of squamous ulcers:

1. Grade 0: Epithelium is intact and shows no appearance of hyperemia.
2. Grade 1: The mucosa is intact, but there are areas of reddening (hyperemia) or hyperkeratosis.
3. Grade 2: Small, single, or multifocal superficial erosions.
4. Grade 3: Large single or multifocal ulcers, or extensive superficial lesions.
5. Grade 4: Extensive lesions with deep ulceration and areas of active bleeding.

Step 5: Implementing a Diagnostic Treatment Trial

In some field scenarios where a gastroscope is unavailable, a veterinarian may suggest a "diagnostic trial" using FDA-approved omeprazole. This involves administering a full treatment dose for 7 to 10 days. If the horse shows a significant improvement in appetite and attitude, it supports the diagnosis of EGUS. However, this is not a substitute for scoping, as it will not identify the location or severity, which is critical for determining if Sucralfate or other mucosal protectants are needed alongside acid suppressors.

Comparative Pathophysiology: ESGD vs. EGGDS

Understanding where the ulcers are located is essential for choosing the right medication. Squamous ulcers respond well to proton pump inhibitors, whereas glandular ulcers often require a more complex pharmaceutical approach involving mucosal coating agents and misoprostol.

Resolving Diagnostic Discrepancies and Treatment Refractory Cases

Sometimes, a horse may show every classic sign of ulcers, but a gastroscopy reveals a clean stomach. In these instances, the issue may lie further down the digestive tract or stem from a secondary source.

• Right Dorsal Colitis or Hindgut Acidosis
  
  
  • Root Cause: Excess starch reaching the cecum and large colon, causing a drop in pH and mucosal inflammation in the hindgut.
  • Actionable Fix: Reduce grain intake, eliminate alfalfa pellets (if over-used), and introduce a high-quality hindgut buffer or pre/probiotic designed to stabilize cecal pH.
• The "Clear Scope" but Persistent Symptoms
  
  
  • Root Cause: Chronic low-grade lameness (such as hock arthritis or navicular syndrome) can cause secondary stress that mimics ulcer behavior.
  • Actionable Fix: Perform a full lameness workup, including flexion tests and diagnostic nerve blocks, to ensure the "girthiness" isn't actually a referred pain response from distal limb discomfort.
• Non-Responsive Glandular Ulcers
  
  
  • Root Cause: Bacterial colonization of the ulcer site or high cortisol levels from environmental stressors (e.g., constant stall confinement).
  • Actionable Fix: Consult with a veterinarian about adding a course of antibiotics (like trimethoprim-sulfas) or Misoprostol, and increase turnout time to at least 12 hours a day in a social herd environment.

Frequently Asked Questions

Can I use "pop rocks" or generic omeprazole to diagnose ulcers?

While compounded or generic versions are available, they often lack the enteric coating necessary to survive the acidic environment of the stomach. For an accurate diagnostic trial, only use FDA-approved, paste-form omeprazole that is specifically formulated for equine gastric transit to ensure bioavailability.

How long does it take for a horse’s behavior to improve after starting treatment?

Most owners observe a noticeable improvement in appetite and "brightening" of the horse's eye within 3 to 5 days of starting a full dose of omeprazole. However, complete mucosal healing of Grade 3 or 4 ulcers typically requires a minimum of 28 to 60 days of continuous therapy.

Does feeding alfalfa help prevent ulcers?

Yes, alfalfa is high in calcium and protein, which act as natural buffers against gastric acid. Feeding a small flake of alfalfa approximately 30 minutes before exercise can create a "protective mat" on top of the liquid acid, reducing the risk of squamous splashing during movement.

My horse only acts up when being saddled; is that always ulcers?

Not necessarily, but it is a primary clinical sign. You must also rule out poor saddle fit, kissing spines (overriding dorsal spinous processes), or rib cage soreness. If the behavior persists after a professional saddle fitting, a gastroscopy is the logical next step.

Can stress alone cause ulcers even if the diet is perfect?

Absolutely. High cortisol levels associated with transport, social isolation, or frequent competition can reduce blood flow to the stomach lining. This diminishes the production of the protective mucus and bicarbonate layer, making the glandular mucosa susceptible to even normal levels of stomach acid.

Ensure Your Horse’s Long-Term Digestive Health

Early detection of gastric ulcers is the key to maintaining your horse's performance and well-being. By combining vigilant behavioral monitoring with professional diagnostic imaging, you can resolve discomfort and prevent the recurrence of this pervasive condition.