Feeding cannot cure a gastric ulcer, but it is the biggest thing an owner controls in whether one forms, heals or comes back. Diagnosis is a gastroscope and treatment is a vet's call; this guide covers the part in between, using what Australian feed makers publish on the subject: how to feed a horse that has ulcers or is prone to them, what to avoid, and which products in our range are built for it.
First, the vet
Ulcers are confirmed by gastroscopy and treated with prescription medication. Feed changes support that; they do not replace it. Hygain's own ulcer article also warns against long treatments with non-steroidal anti-inflammatory drugs such as phenylbutazone, which is a conversation to have with your vet if your horse is on them.
Why feeding matters
A horse's stomach produces acid continuously, and chewing forage is what buffers it with saliva. Hygain's article puts a number on what happens when that stops: if feed is withheld, the pH in the stomach drops to 2 in 21 hours. Its summary of the least harmful setup is blunt: pasture and free access to hay is the most natural and least ulcerogenic environment. Every recommendation below follows from that.
What to feed
- Forage all day. Hygain: feed ad lib hay, and avoid long periods without food. If the horse is a good doer, slow the intake with small-hole nets rather than cutting hours without hay.
- Lucerne before work. Hygain: feed a small amount of lucerne chaff or hay prior to work; lucerne acts as a physical barrier and its calcium buffers the acid. Perrys Lucerne Chaff is the straightforward option; Johnsons Alfalfa Plus is the bagged alfalfa-based feed.
- Small, frequent hard feeds. Hygain: feed frequent small meals, and place feed bins on the ground, which mimics grazing and stimulates more saliva.
- Low starch, low NSC. High-starch grain meals are what the makers design ulcer-prone feeds to avoid. Hygain Zero is the clearest example: grain free, maximum 1.5 percent starch, 35 percent fibre, 15 percent protein, 8 MJ per kilogram, and Hygain lists horses susceptible to gastric ulcers among the horses it is for. For a horse that does not need a full feed, Hygain Meta Safe is the cereal-grain-free balancer at a maximum 1.5 percent starch, fed at a small daily rate.
- Oil and fibre for energy, not grain. If the horse needs condition, the makers' answers are oil and digestible fibre: Hygain RBO rice bran oil supplies oil-based energy without the starch and sugar of grain; CoolStance copra is virtually starch-free at 11 percent NSC; Hygain Tru Beet is a low sugar, low starch soaked fibre; Hygain Tru Gain is the high-fat supplement Hygain lists for horses prone to tying up or stomach ulcers. Our copra, lupins and beet pulp guide goes through the straights in detail.
- A buffer in the feed. Hygain's acid buffer article names calcium as one of the most common acid buffers in equine nutrition, lucerne as the popular option, and red seaweed (Lithothamnion calcareum) as the more technical one, with a buffering effect it says lasts 2 to 4 hours after consumption. Hygain Digest & Protect is formulated with Lithothamnion calcareum plus slippery elm, digestive enzymes, glutamine and threonine, prebiotics and probiotics. Other gut-support supplements in the range include Kohnke Gastro-Coat and Kelato GastroAID Everyday; follow their label directions.
What to avoid
- Long gaps without forage. Hygain's 21-hour figure is the reason.
- Working on an empty stomach. Hygain: do not exercise on an empty stomach, as this allows acid to attack the stomach wall when it is empty.
- Large grain meals. Split any hard feed into small meals and keep the starch low; if a feed does not print its starch or NSC figure, ask the maker.
- Stress. Hygain lists avoiding physical and behavioural stress alongside the feeding points; travel, changes of company and box rest all count.
- Assuming a supplement fixes it. Buffers and gut supplements support a management plan; they are not the treatment.
A sample day for a 500 kg ulcer-prone horse in light work
Hay or pasture available around the clock (Hygain's ad lib recommendation), with lucerne chaff before any ridden work. Two small hard feeds rather than one: a low-starch base such as Hygain Zero at the rate on the bag, or Meta Safe if the horse holds condition on forage alone, with copra, Tru Beet or rice bran oil added only if condition is needed, and a buffer such as Digest & Protect mixed through as directed. Bins on the ground, clean water always. Reassess with your vet, not by eye, because ulcers are scoped, not guessed.
Frequently asked questions
What is the best feed for a horse with ulcers?
There is no single feed; the makers' shared answer is forage first, low starch, small meals and a buffer. Among complete feeds, Hygain Zero is the one Hygain explicitly lists for horses susceptible to gastric ulcers, with a maximum 1.5 percent starch.
Does lucerne help with ulcers?
Hygain says yes, two ways: as a physical barrier in the stomach and because its calcium buffers acid. It recommends a small amount of lucerne chaff or hay before work.
Can I still feed grain?
The makers' ulcer-prone feeds are built to avoid grain starch, and Hygain's advice is frequent small meals. If grain stays in the ration, keep the meals small and talk to your vet or a nutritionist about the total starch.
How long can a horse go without hay?
Hygain's figure is that stomach pH drops to 2 within 21 hours of feed being withheld, which is why it recommends ad lib hay and no long gaps without food.
Do ulcer supplements work?
Hygain reports a 2 to 4 hour buffering effect from Lithothamnion calcareum, which is what its Digest & Protect is built around. That is support between feeds, not a cure; treatment is prescribed by a vet after a scope.
Shop next: Horse Feed · Hygain Zero · Hygain Digest & Protect · Perrys Lucerne Chaff · Horse Health & Supplements
Sources
Product facts in this guide are taken from the manufacturers' own pages listed below and from the product listings on this site; general care points are given as practical guidance, not veterinary advice. Last reviewed 17 September 2026.
- Hygain: Ulcer treatment for horses: why and what to do
- Hygain: Acid buffers, do they really work?
- Hygain: Zero
- Hygain: Tru Gain
- Stance Equitec: CoolStance Premium Copra Meal