Gastric ulcers are a serious, yet common, condition that can affect any horse, not just dressage and other performance horses. People often think “ulcers” when a horse swishes his tail or becomes spooky, but those behaviors can be caused by a variety of problems, including back pain, ill-fitting tack and so on and do not necessarily indicate ulcers.
If you suspect your horse might have ulcers, look for the following clinical signs: Recurrent mild to severe non-specific colic, mild to moderate lack of appetite, weight loss, poor skin, decline in body condition, decreased athletic performance, teeth grinding, excessive salivation, yawning, decrease in feed efficiency, mild diarrhea and increased time spent laying down. Ulcers also can cause a host of behavioral changes and problems, such as unwillingness to bend in certain directions, stiffness, crankiness, reluctance to move forward, vague sore-back symptoms, tail swishing, ear pinning or unhappiness with work.
Gastric health issues have several potential causes, including imbalances in the horse’s diet or periods of food deprivation—several missed meals or fasting can cause serious stomach ulceration. Other causes can be stall confinement, a diet that includes a significant amount of high-concentrate feeds (grain), prolonged nonsteroidal anti-inflammatory drug (NSAID) therapy, poor mastication (chewing), trailering, new environments, changes in daily routines, surgery or other medical stresses and periods of prolonged, strenuous training.
If you suspect your horse might have ulcers, consult your veterinarian. He can perform a gastric video endoscopy, using a scoring system to classify the severity of the ulcers. This is considered the gold standard for stomach ulcer diagnosis. Fortunately, you can prevent gastric ulcers in your horse. Here is a checklist of guidelines you can follow:

• Go over prevention techniques and treatment protocols thoroughly with your veterinarian.

• Feed free-choice forage (roughage) or hay three to four times a day or in a continuous feeder

• Feed less concentrates (grains)

• Feed low omega-6 and high omega-3 oil to replace calories lost by feeding less corn, oats and wheat

• Decrease or discontinue oral or intravenous NSAIDs if possible

• Do not fast your horse or decrease his feed intake unnecessarily

• Prevent surgical pain if possible

• Offer healthy snacks and supplements—such as omega-3 fatty acids, mucilage, antioxidants, trace minerals or vitamins—before training or showing

• Avoid stress by not over-exercising or over-training

• Provide anti-acidic supplements to decrease stomach acid levels 

• Use omeprazole to prevent and treat gastric ulcers, but do not overuse and do not rely on a no-side-effects statement when administered for an exceptionally long time.

• Use other anti-ulcer medications under your veterinarian’s recommendations

• Monitor your horse for any continuation of symptoms of gastric ulceration, and have his stomach re-scoped to be sure treatment and prevention protocols are working

Don’t underestimate the negative effects stomach ulcers have on athletic performance, and don’t underestimate the positive effects of effective ulcer prevention and control.

Doug Herthel, DVM, is the founder of Alamo Pintado Equine Medical Center in Los Olivos, California, and Platinum Performance, a leader in equine supplements and equine health education.