Feeding Horses to Prevent Colic: What Actually Works and What to Avoid

By Dr Duncan Houston

If your horse has had colic before, feeding is one of the most powerful ways to reduce the risk of it happening again.

Colic is not just bad luck. In many cases, it is the result of how the horse is managed day to day, especially diet, feeding frequency, and movement.

The key is not just what you feed, but how the digestive system is being used.

Quick Answer

Most colic cases are linked to feeding practices that do not match the horse’s natural grazing behaviour. A forage-based diet, minimal grain, consistent feeding routine, adequate hydration, and regular movement significantly reduce the risk of colic.

Why Horses Are So Sensitive to Feeding Changes

Horses evolved to graze continuously.

This means:

• small amounts of feed entering the gut constantly

• steady microbial fermentation in the hindgut

• consistent gut movement

Modern feeding often does the opposite:

• large meals

• long periods without food

• high-starch concentrates

This creates instability in the digestive system.

In practice, most feeding-related colic comes down to disruption of the hindgut environment.

The Real Problem With Grain

Grain is not inherently bad, but it is often overused.

The issue is starch.

When too much starch is fed:

• it cannot all be digested in the small intestine

• excess starch reaches the hindgut

• fermentation changes rapidly

This leads to:

• gas production

• acid buildup

• microbial imbalance

These changes increase the risk of:

• gas colic

• impaction

• more severe digestive disturbances

In practice, large grain meals are one of the most common risk factors.

How Serious Is Your Horse’s Risk?

Low Risk

• mostly forage-based diet

• regular turnout

• consistent routine

What this means: baseline risk is low

Moderate Risk

• moderate grain feeding

• limited turnout

• occasional feeding changes

What this means: some disruption to gut stability

High Risk

• large grain meals

• low forage intake

• inconsistent feeding schedule

• limited movement

What this means: significantly increased colic risk

Critical Risk

• recent diet change

• dehydration

• previous colic history

• high-stress environment

What this means: immediate management changes needed

Feeding Strategies That Actually Reduce Colic Risk

Prioritise Forage

This is the single most important rule.

• hay or pasture should form the majority of the diet

• aim for consistent intake throughout the day

Forage supports:

• stable gut microbes

• consistent motility

• normal fermentation

Feed Little and Often

If concentrates are needed:

• divide into multiple small meals

• avoid large single feeds

Large meals overload the digestive system.

Keep the Diet Consistent

Sudden changes are a major trigger for colic.

Any feed change should be introduced gradually over at least 7 to 10 days.

This allows the gut microbiome to adapt.

Maximise Turnout and Movement

Movement is essential for gut function.

• promotes motility

• reduces gas buildup

• supports overall digestive health

Horses confined for long periods are at higher risk.

Maintain Hydration

Water intake is critical.

Dehydration increases the risk of:

• impaction colic

• reduced gut movement

Practical steps:

• ensure constant access to clean water

• encourage drinking during travel or heat

• consider soaking feeds if needed

Use Slow Feeding Systems

Hay nets or slow feeders:

• extend feeding time

• mimic grazing

• reduce long fasting periods

This helps stabilise digestion.

What To Do Right Now

If your horse is at risk of colic:

• review how much forage is being fed

• reduce large grain meals

• increase feeding frequency

• check water intake

• ensure consistent routine

• increase turnout where possible

If your horse has had colic before, these changes are not optional. They are essential.

When Is This an Emergency?

Feeding helps prevent colic, but you still need to recognise it early.

Treat as urgent if your horse shows:

• looking at the flank

• pawing or rolling

• reduced appetite

• reduced manure

Treat as an emergency if:

• severe pain

• continuous rolling

• rapid deterioration

Early intervention improves outcomes significantly.

Common Mistakes

• feeding large grain meals

• underestimating the importance of forage

• making sudden diet changes

• restricting movement

• ignoring water intake

• assuming colic is random

In practice, many colic cases are predictable based on feeding patterns.

Long-Term Prevention

The most effective prevention strategy is simple:

• forage-based diet

• minimal and controlled grain use

• consistent feeding routine

• regular movement

• adequate hydration

Colic risk drops significantly when feeding matches natural behaviour.

Frequently Asked Questions

Can hay cause colic?
Rarely. Poor-quality or moldy hay can be an issue, but good forage is generally protective.

Do horses need grain?
Not always. Many horses can maintain weight and performance on forage alone.

Is pasture better than hay?
Both can work well. Pasture provides natural feeding behaviour, but sugar levels must be managed.

How quickly can diet changes cause colic?
Within days. Sudden changes can disrupt the gut rapidly.

Does feeding more often really help?
Yes. Smaller, more frequent meals better match natural digestive function.

Final Thoughts

Colic prevention is not complicated, but it does require consistency.

The key questions are:

• is the diet forage-based

• are meals small and frequent

• is the routine consistent

• is the horse moving enough

• is hydration adequate

When these are controlled, many cases of colic can be avoided.

If your horse has had colic before or you are unsure whether your feeding routine is truly safe, ASK A VET™ can help you review your current setup and guide you toward a more stable, lower-risk plan.