Feeding to Reduce the Risk of Colic in Horses

What is colic?

Colic is the general term for abdominal pain in horses.

The cause may involve the stomach, small intestine or large intestine, and pain can occasionally arise from structures outside the gastrointestinal tract. Some cases are mild and resolve with treatment; others require urgent referral and surgery.

Because the early signs of colic can look similar, owners should not try to diagnose the cause from behavior alone. For a full breakdown of signs, types and treatment, see our complete guide to colic in horses.

Diet and management are only part of the picture. Age, previous colic, dental disease, parasites, crib-biting, changes in exercise or housing and some medical conditions may also alter risk.

A previous episode of colic is a reason to work with the veterinarian on an individual prevention plan.

What does the evidence say about feeding risk?

Research shows that a horse's risk of colic may increase when they are fed large amounts of concentrate, when their feed changes suddenly, or when they move to a different barn or pasture.

The practical takeaway is simple: make feed and management changes gradually and avoid feeding large concentrate meals.

1. Start with enough forage

Forage supports normal chewing, saliva production, gastrointestinal fill and hindgut fermentation.

Current guidance recommends that most healthy adult horses receive at least 1.5% of their bodyweight in forage dry matter (DM) each day, with many consuming closer to 2%. For a 1,100 lb horse, this equals 16.5–22 lb of actual dry plant material.

Because forage naturally contains water, the amount fed or consumed will be higher when weighed "as fed." For example:

• Dry hay at 85% dry matter: approximately 19–26 lb per day
• Baleage or haylage at 60% dry matter: approximately 28–37 lb per day
• Fresh pasture at 20% dry matter: approximately 83–110 lb consumed per day

These figures are estimates because the water content of hay, haylage and pasture can vary. Forage analysis provides the most accurate dry-matter value.

Where possible, spread forage across the day and avoid routine gaps of more than about four to five hours.

Horses that gain weight easily still need plenty of fiber and time to eat forage. Their weight can be managed safely with:

• Tested lower-calorie forage
• Slow feeders
• Balanced weight-loss diet designed by an equine nutritionist

Avoid severely restricting forage without professional guidance.

Chewing forage produces saliva, which helps buffer stomach acid. Long-stem forage may also form a fiber layer that helps protect the sensitive upper part of the stomach. However, forage is not a treatment for glandular stomach disease and cannot be relied on to prevent the intestines from twisting.

2. Keep concentrate and starch intake as low as practical

Studies suggest that horses fed larger amounts of concentrate, such as grain or other concentrate feed, may have a higher risk of colic.

Some studies found increased risk above 5.5 lb per day, but this is not a safe limit for every horse. The right amount depends on the horse, the feed, and its management.

Where possible, meet the horse's energy needs with forage and high-fiber feeds first, then add only as much concentrate as needed.

For horses at risk of squamous gastric ulcers, it is recommended to base the diet on forage and high-fiber feeds rather than concentrate meals — such as grain, pellets, or other concentrate feeds.

Starch levels vary widely between feeds, so there is no single weight limit that is suitable for every product. Follow the manufacturer's feeding directions and ask your veterinarian or equine nutrition professional for advice if needed. These feeding practices may support stomach health, but they cannot guarantee that a horse will avoid gastric ulcers or colic.

If concentrate is needed, divide it into smaller, more frequent meals rather than limiting the horse to two large feeds. Beet pulp, soy hulls, stabilized rice bran and appropriately introduced vegetable oil can provide alternatives to some cereal starch, but the whole ration still needs to be balanced for energy, protein, minerals and the horse's health status.

Processing grains such as barley and corn can make their starch easier to digest before it reaches the hindgut. Oats are usually more easily digested than unprocessed barley or corn. However, processing does not make large grain meals safe. Keep meals small and consider the total starch, type of grain, and the individual horse.

3. Change feeds and management gradually

Recent change is one of the most consistent modifiable risk factors for colic.

Introduce a new hay, pasture, concentrate or supplement gradually over 14 days whenever circumstances allow. This helps the hindgut microbial community and the horse's intake pattern adapt to a different substrate.

Forage changes matter just as much as concentrate changes.

• Blend old and new hay across the transition
• Introduce new pasture in controlled increments
• Avoid changing feed, housing and exercise all at once

When an abrupt change is unavoidable, monitor appetite, water intake, manure and comfort closely.

4. Make water easy to drink

Provide clean, fresh and palatable water at all times. Limited water access or reduced water intake has been linked to an increased risk of colic.

A horse's water needs may increase with:

• Dry forage
• Exercise
• Lactation
• Warm weather

Cold weather can also cause some horses to drink less. Check troughs and other water sources daily to ensure they are clean and working properly. When traveling, offer familiar water whenever practical, and investigate any sudden change in your horse's drinking habits.

If well water or other unfamiliar water tastes salty or unpalatable, have it tested and discuss the results with your veterinarian or equine nutrition professional. Water quality cannot be judged by appearance alone.

5. Manage pasture access carefully

Pasture turnout can provide several benefits, including:

• Natural grazing behavior
• Gentle movement
• Social contact with other horses

Regular turnout may also help reduce colic risk. However, unlimited pasture is not suitable for every horse.

Horses that are overweight or at risk of insulin dysregulation or laminitis may need:

• Controlled grazing time
• A grazing muzzle
• Tested, lower-sugar forage
• An individual management plan from a veterinarian or equine nutrition professional

The sugar and starch content of pasture changes with the plant species, growth stage, weather and time of day. Introduce horses to lush pasture gradually, particularly after they have had limited access.

Seasonal pasture changes may affect some horses, but spring or fall fructans alone have not been proven to cause colic under normal grazing conditions.

6. Prioritize clean feed, good chewing and a consistent routine

Good feed hygiene and regular feeding routines can help support healthy digestion.

To keep feed safe:

• Do not feed hay, baleage (wrapped hay) or haylage, grain or supplements that are moldy, unusually hot, unexpectedly wet, very dusty, contaminated or foul-smelling.
• Store feed in a clean, dry place protected from moisture, pests and contamination.
• Weigh feeds instead of relying on scoops, as different feeds can vary considerably in weight.
• Keep feeding times and meal sizes as consistent as possible.

Good chewing is also important. Arrange regular dental examinations to identify painful teeth or difficulty chewing. Horses with dental problems or a history of impaction may struggle with coarse forage and may need chopped, soaked or complete forage-replacement feeds. Ask your veterinarian or equine nutrition professional to help select a suitable option.

Parasite control should be based on fecal egg counts — tests that measure worm eggs in manure — and veterinary advice. Avoid deworming every horse on a fixed calendar without considering test results and individual risk.

7. Reduce sand ingestion

Horses may swallow sand when grazing short pasture or eating directly from sandy ground. Over time, sand can irritate or block the intestine, potentially causing diarrhea, weight loss or colic.

To reduce sand intake:

• Feed hay and commercial concentrate from clean feeders, tubs or large rubber mats.
• Provide enough forage when pasture is short or sparse.
• Avoid feeding directly from bare or sandy ground.
• Limit access to areas where the soil is heavily disturbed or contaminated.

At-home manure tests can sometimes reveal sand, but they cannot reliably show how much has collected in the intestine.

If you suspect sand accumulation — particularly if your horse has ongoing diarrhea, weight loss or signs of colic — contact your veterinarian. Further examination and imaging may be required.

Evidence for routine psyllium treatment at home is mixed. Significant sand accumulation may require veterinary treatment using psyllium alongside other therapies. Follow your veterinarian's recommended protocol rather than relying on hay or a routine supplement to remove accumulated sand.

Where do gastric ulcers fit?

Not all gastric ulcers are the same. Horses can develop ulcers in two different areas of the stomach:

Some horses with gastric ulcers may have a reduced appetite, poor performance or discomfort around feeding. However, many show no obvious signs. These signs can also be caused by other health problems, and a horse showing signs of colic will not necessarily have gastric ulcers.

Gastroscopy is the most reliable way to diagnose gastric ulcers and identify which part of the stomach is affected. If you suspect gastric ulcers, speak with your veterinarian about appropriate testing, treatment and management.

Where does DigestiveHP and Stress Paste fit?

DigestiveHP contains a blend of ingredients selected to support normal digestion and a healthy gut environment:

• Seaweed derived calcium, magnesium and alfalfa provide natural buffering ingredients that help support a healthy digestive environment.
• Saccharomyces cerevisiae fermentation products (Yeast Culture) support the beneficial microbes involved in hindgut fermentation and fiber digestion.
• Digestive enzymes help the horse break down carbohydrates and make use of nutrients in the diet.
• Amino acids, including glutamine, threonine, proline and serine, provide building blocks used by the body to maintain the protective lining and mucus layer of the digestive tract.
• DigestiveHP also contains a mycotoxin binder, designed to bind certain unwanted compounds that may occur in feed, and a source of vitamin C for antioxidant support.

Stress Paste is designed to support good gut health during short-term periods of stress, such as traveling, competition or a change in routine.

Research into the individual ingredients provides a scientific basis for their inclusion. However, these products should be used to complement good feeding and management. Adequate forage, constant access to water, small concentrate meals and gradual changes remain the foundations of digestive health. These supplements support normal digestive function but are not treatments for colic or gastric ulcers.

Take-home messages

• No feeding program can prevent every colic, but consistent management can reduce avoidable risk.
• Feed a forage-first ration, measured on a dry-matter basis, and avoid prolonged gaps without forage.
• Keep concentrate and starch as low as practical; if needed, feed small meals and consider fiber- and fat-based energy sources.
• Change hay, pasture, concentrates, supplements, housing and workload gradually.
• Maintain water access, feed hygiene, dental care, parasite control, turnout and movement.
• Prevent sand intake rather than relying on an unverified clearance routine.
• Use supplements only as adjuncts to sound nutrition and veterinary care.
• Treat any suspected colic as a prompt veterinary call — see what to do while you wait for the vet.

Frequently asked questions