A Lesser-Known Significant Contributor to Equine Gastric Ulcers
You’ve likely heard the statistic by now: up to 90% of racehorses and 60% of performance horses suffer from gastric ulcers. Shocking, right?
But here’s what’s even more sobering: ulcers aren’t limited to elite athletes.
Foals, yearlings, sport horses, show horses, and even pleasure horses are developing stomach ulcers at alarming rates. Studies suggest 50% or more of these horses may experience ulcers at some point in their lives. And the moment training intensifies? So does the risk.
A 2015 Consensus Statement from the European College of Equine Internal Medicine shared some startling patterns:
37% of untrained Thoroughbreds had ulcers. That jumped to 80–100% within 2–3 months of training.
44% of untrained Standardbreds had ulcers. That spiked to 87% during training and racing.
48% of endurance horses had ulcers, but during competition season, rates rose to 66–93%.
Even show, sport, and pleasure horses averaged 58%.
Only 11% of horses that stayed home and competed rarely showed signs of ulcers.
The data paints a clear picture: the way we’re managing horses—training schedules, stress loads, feeding practices—is breaking down the very system meant to nourish and protect them.
So, how do we shift this?
What’s Really Going On in the Gut?
To understand how ulcers form, we have to understand the horse’s digestive design. Unlike humans, horses secrete stomach acid continuously—even when they’re not eating. Add stress, fasting periods, or high-concentrate feeds, and it becomes a perfect storm.
The stomach has two distinct regions:
The upper squamous region: This is more vulnerable, thinly lined, and with minimal protection from acid.
The lower glandular region: This area has built-in buffering systems like mucus and bicarbonate.
Most ulcers form in that upper region, where acid can erode the lining quickly, sometimes within hours of an empty stomach or high-stress experience.
The signs? Often subtle:
Declining performance
Changes in appetite or body condition
Dullness or irritability
Low-grade colic or girth sensitivity
Resisting training or new requests
And here’s the truth: many horses who “just seem a little off” are quietly navigating chronic digestive discomfort.
There’s More to the Story: The Role of Oxidative Stress
While feeding practices and stress are often blamed, there’s a lesser-known contributor that deserves more attention: oxidative stress.
Oxidative stress occurs when free radicals overwhelm the body’s ability to neutralize them. It’s both a cause and a consequence of digestive imbalance, and that includes ulcers.
One study published in the Journal of Equine Veterinary Science compared horses with ulcers to clinically healthy horses. The ulcer group had:
Higher levels of malondialdehyde (MDA)—a marker of cell damage
Lower antioxidant levels like glutathione (GSH), superoxide dismutase (SOD), and total antioxidant capacity (TAC)
Another study in Colombia revealed that phenylbutazone (PBZ), a commonly used NSAID in ulcer protocols, actually causes oxidative stress in the gastric lining. It alters the oxidant-antioxidant balance, making healing even harder.
In other words, we may be treating ulcers with substances that make the root problem worse.
The Missing Link? Rebalancing the Terrain
Healing ulcers isn’t just about suppressing acid; it’s about restoring terrain.
That includes feeding strategies, emotional regulation, and yes, addressing oxidative stress. One of the most researched ways to do that is through Nrf2 activation, which supports the body in reducing oxidative damage and restoring internal balance naturally. Click here to connect with me to learn more about an Nrf2 activation product proven to reduce oxidative stress by 40% in 30 days.
If your horse has been stuck in the ulcer cycle, or you want to get ahead of it before symptoms escalate, there is another way. And it starts with seeing the full picture of your horse's health.
Want to go deeper?
You’re invited to explore our gentle, whole-horse-centered mini course:
But My Horse Has… Gastric This on-demand workshop shares a rhythm-based, terrain-informed approach to ulcer support, including natural tools, root causes, and ways to stop the cycle of suppression.
Whether you’re looking for alternatives or want to get more from your current approach, this is a powerful place to start.
>>> Click Here to Learn More about the Mini Course!
Let this be the moment you step into a different rhythm, for your horse’s gut, your peace of mind, and the health they were always meant to have.