Gastric ulcers are painful lesions that form inside a horse's stomach. These ulcers are increasingly common in both performance and pleasure horses and are often caused by modern feeding practices especially diets high in sugar and starch (NSC). By understanding the link between stomach anatomy, feeding routines, and diet composition, horse owners can prevent ulcers at the root cause, not just manage the symptoms.
Understanding Equine Stomach Anatomy and Gastric Ulcers
The horse’s stomach is divided into two regions:
- Squamous (upper) region: This area has a thin lining and limited protection from stomach acid. Most ulcers occur here.
- Glandular (lower) region: This section secretes acid for digestion and is protected by a thick mucous layer.
In a healthy horse, food enters the stomach through the upper squamous region (pH 5–6) and then moves to the glandular region (pH ~4), where gastric acids break it down further. Horses are naturally trickle feeders designed to graze on fibre-rich forage for up to 18 hours a day. This constant intake buffers stomach acid and keeps the digestive system in balance.
What Causes Gastric Ulcers in Horses?
Several factors contribute to ulcer development, including:
- Stress (travel, competition, social disruption)
- Parasitic infections
Infrequent feeding (leading to an empty stomach)
- High NSC diets (sugar and starch-rich grain-based feeds)
Why High-NSC Diets Are a Problem
When horses are fed large, grain-based meals (typically >12% NSC), digestion begins in the upper stomach. Here, sugars and starches cause a rapid drop in pH, increasing acidity in the unprotected squamous region. This “acid splash” effect damages the delicate stomach lining and can lead to ulcers especially when the stomach is empty between meals.
Feeding Practices That Prevent Ulcers
To prevent gastric ulcers and maintain digestive health—without compromising performance consider these practical strategies:
- Feed a Low-NSC (<12%) Diet
Choose grain-free or low-starch feeds to avoid triggering acid production and glucose spikes. Look for ingredients like beet pulp, soybean hulls, and coconut meal.
- Avoid Shock/Pulse Feeding
Feeding high-NSC feeds just twice daily results in “pulse feeding,” which overwhelms the stomach with acid. Horses should ideally eat small amounts frequently throughout the day.
- Choose “Slow Energy” Feeds
Feeds like CoolStance® Copra Meal provide high energy without spiking blood sugar or causing excess gastric acid. They support calm energy, muscle development, and gut health.
- Provide Ad Lib Forage
Keep hay available at all times to prevent the stomach from becoming empty. Even modest hay intake helps buffer gastric acid.
- Supplement When Necessary
If pasture or hay is lacking, add a vitamin-mineral supplement to ensure balanced nutrition. Probiotics can also help support gut health, especially after stress or medication. Learn more about slow and fast feeds for horses
The Problem with Treating Only the Symptoms
Ulcer medications like omeprazole can be effective, but they only mask the problem if the horse’s diet remains high in NSC. Continued reliance on medications without addressing feeding practices can lead to serious long-term complications, including:
- Insulin resistance
- Obesity
- Cushing’s disease
- Tying up (exertional rhabdomyolysis)
- Laminitis
The Bigger Picture: Equine Digestive Anatomy
The horse’s stomach is less than 10% of its total GI tract. The majority of digestion occurs in the hindgut, particularly in the caecum and colon, which are designed to ferment fibre. Horses are hindgut fermenters, unlike cattle (foregut fermenters), and thrive on a forage-based diet.
High-NSC diets not only affect the stomach but also disrupt the hindgut microbiome, leading to acidosis, colic, and inflammation throughout the digestive system.
Recent Research: Low-NSC Feeds for Performance Horses
New feeds such Coolstance copra meal with high digestible energy (DE) and low NSC content offer performance horses a safer way to meet energy demands without risking ulcers or metabolic disease. These feeds support:
- Do not cause glucose or insul;in spikes
- A shiny coat and top-line development
- Calm, sustained non glucose energy
- Healthy gut function
- Reduced inflammation
Non medicated supplements.
The veterinary solution is to treat horses with ulcers with medicated products including Ulcaguard, GastroGuard containing Omeprazole, These are proton pump inhibitors whish decrease the amount of acid produced in the stomach. Long term use of Omeprazole can affcet mineral balance, especially calcium absorption.
Research has shown that feeding turmeric (Curcumin xanthorrhiza) to horses with ulcers suppressed the formation of ulcers in the squamous region of the stomach. see Pre-Treatment with Turmeric (C. Xanthorrhiza) Reduces the Severity of Squamous Gastric Ulceration in Feed Restricted Horses.
Ulcabuf is a non medicated feed supplement based on Curcumin xanthorrhiza
Conclusion: Feed Smarter, Not Just More
Gastric ulcers in horses are often the result of high-NSC diets and modern feeding schedules. Simply treating ulcers with medication without addressing the root cause can set the horse up for bigger metabolic problems in the future.
To prevent ulcers and promote long-term health:
- Feed low-NSC diets such as Coolstance copra
- Avoid grain-based “pulse” meals
- Provide hay continuously
- Use slow-release, fibre-based energy sources
- Use non medicated supplements such as Ulcabuf
Good feeding is good management. With smarter feeding choices, you can support your horse’s performance, comfort, and wellbeing from the inside out.
