If you have a performance horse who sours when the trailer pulls in, goes off his feed at shows, or feels tight through the girth after a hard week, you've probably already wondered about ulcers. Equine gastric ulcer syndrome (EGUS) is common in show and race horses, and owners talk about it a lot for good reason. Below we go through how the horse’s stomach works and what raises the risk. We also cover what belongs in a conversation with your veterinarian, and how feeding and daily habits fit around that care. Around it, not instead of it.
What EGUS actually means
Veterinarians started using the term equine gastric ulcer syndrome (EGUS) in 1999 to describe lesions in the terminal esophagus, the non-glandular and glandular stomach, and the proximal duodenum. It shows up across breeds and ages. The risk climbs with intense exercise, stall confinement, transport stress, intermittent feeding, and high-grain diets. Horses secrete gastric acid around the clock, so a long stretch without forage leaves the upper stomach sitting in a low-pH environment.
Diagnosing and treating EGUS is your veterinarian's job. Medication usually focuses on raising stomach pH and supporting healing of the lesions under veterinary guidance. Ulcers come back often, so most clinicians also talk about diet and management once the medical plan is underway. Supplements are nutritional support only. They do not diagnose, treat, cure, or prevent ulcers or any other disease.
Start with the horse's day
Before you reach for any product, look at how the horse spends his day:
- Give him steady access to good-quality forage so his stomach is rarely empty.
- Lean toward more fiber and less sweet feed, and keep grain meals small when he needs grain.
- Choose oats or barley over heavy molasses-based concentrates when your nutritionist agrees.
- Cut down on trailer and stall stress where you can, and keep turnout in the routine.
- If you soak hay, about 60 minutes in cool water can help reduce dust and surface residues. Ask your vet or nutritionist what makes sense for your barn.
Research often cited by equine nutritionists suggests keeping sweet-feed-type grain under roughly 0.5 kg per 100 kg body weight when NSC is high, and keeping an eye on total non-structural carbohydrate intake. Horses in high-intensity work still need their calories. The trick is getting them in without oversized starch meals. Alfalfa or grass-alfalfa mixes show up often in ulcer-conscious rations because they can help buffer acidity compared with some grass-only hay programs. Work out the details for your horse with your vet or equine nutritionist.
Where nutrition support fits
Once the veterinary plan and the forage program are in place, a lot of owners look for daily gut support from foregut to hindgut. Many also want help holding topline when appetite or workload has been hard on the horse. That's where ImmuBiome's gut-first approach comes in, built on medicinal mushroom mycelium, bovine colostrum, prebiotics, and probiotics. These formulas are made for horses who need digestive and muscle support. They are not a drug protocol.
Start with ImmuBiome G-Tract
G-Tract is our main formula for foregut-to-hindgut digestive support. Here's what goes into it:
- Turkey Tail and Lion’s Mane, prebiotic-rich mushroom extracts that support a balanced gut environment
- Bovine colostrum, for nutrients that support the natural health of the stomach and gut lining
- Live Saccharomyces spp. and a multi-strain probiotic profile to support a healthy microbiome and nutrient absorption
- Beta-glucans, as part of everyday gut and immune resilience
Mix it into damp feed daily per the label, and let your veterinarian help you adjust the amount to his workload. If your horse shows colic signs, poor appetite, or weight loss, call your veterinarian before anything else.
Add ImmuBiome Lean Muscle when topline needs help
Lean Muscle is the supporting formula, a good partner when topline and condition need work alongside gut support. It's built on bovine colostrum, Reishi, probiotics, and prebiotics, which makes it useful for a horse who needs to fill out while you clean up the ration. Feed it in damp feed per the label directions.
Browse digestive options in our hindgut and digestive support collection.
How many barns use the two together
Owners who feed both often start with a steady daily serving of Lean Muscle while forage and vet care get sorted out. G-Tract then comes in as the main ongoing digestive support, increased gradually so picky eaters accept it. Follow the scoop directions on each product page and pouch, and go slowly with any feed change. These are nutrition routines. They aren't medical treatment schedules for EGUS.
More on the stomach and gut
- Equine Gastrointestinal Series: Gastric Ulceration
- Equine Gastrointestinal Series: Leaky Gut
- Benefits of Probiotic Supplementation
- Mold and Mycotoxin Contamination in the Equine Diet
Who G-Tract suits
G-Tract is a simple daily way to support digestive comfort from foregut to hindgut, especially for a horse in hard work, one who travels a lot, or one on a high-starch program you're trying to scale back. Add Lean Muscle when topline is part of the picture. Mix either one into damp feed, follow the label, and keep your veterinarian in the loop for anything clinical.
These statements are about nutritional support. ImmuBiome supplements are not intended to diagnose, treat, cure, or prevent any disease. Talk with your veterinarian about your horse’s specific needs.
Show weeks, hard work, and acid splash
Hard work is part of the job for many of these horses, and it changes how the stomach behaves. During intense exercise the stomach can be compressed, which lets acidic fluid reach the non-glandular lining more easily. Add a grain meal and a long gap without hay and you have a familiar show-week pattern. Building forage into the trailer day does more for his comfort than any single scoop. Think hay nets that are safe for travel, smaller grain meals, and a quiet cool-out.
NSAIDs belong in the ulcer-risk conversation too, when your veterinarian prescribes them. Never add or stop a prescription drug because a blog said so. If your horse needs pain medication, ask your vet how to protect his stomach while he's on it.
Why this article reads differently now
Earlier versions of this article leaned on disease-treatment language, herbal claims that aren't on today's product pages, and study conclusions we couldn't responsibly repeat without the primary sources in hand. We kept the education on EGUS risk and forage management. The products stay in as nutritional support, with ingredients that match the current G-Tract and Lean Muscle pages: mushrooms, colostrum, prebiotics, probiotics, and, for G-Tract, live yeast cultures.
Questions owners ask us
My horse was scoped and has ulcers. Can G-Tract replace the medication my vet prescribed? It can't. Medication and follow-up scoping are your veterinarian's decisions. G-Tract is nutritional support for digestive balance, meant to go alongside your vet's plan, not replace it.
How should I feed G-Tract and Lean Muscle? Mix both into damp feed. Start with the label amounts, and if you need help matching scoop size to your horse’s weight and workload, ask your veterinarian or ImmuBiome support. Bring in any new product gradually.
Does free-choice hay really matter that much? For most horses it does. Acid production never stops, so long empty stretches are a classic setup for trouble. Forage comes first, then grain and supplements as needed.
