Feeding Horses with Laminitis: What Actually Works and What to Avoid

By Dr Duncan Houston

If your horse has laminitis or is at risk, feeding decisions are one of the most important factors in whether the condition stabilises or worsens.

Many cases of laminitis are not caused by grain overload, but by pasture. Horses that appear to be on a “natural” grass diet are often exposed to high sugar levels that trigger the condition.

This is where most management plans fail. The diet looks normal, but the metabolic impact is not.

Quick Answer

Most laminitis cases are linked to high sugar intake from pasture. Horses at risk should be managed on low-NSC forage, with restricted or controlled grazing, weight management, and careful monitoring of insulin response. Simply limiting grazing time is often not enough.

Why Pasture Causes Laminitis

Grass contains non-structural carbohydrates, mainly sugars and starches.

When a horse consumes high levels:

• blood sugar rises

• insulin levels increase

• blood flow and cellular function in the hoof are disrupted

This leads to inflammation and weakening of the laminae.

In practice, laminitis is often an insulin-driven disease, not just a dietary one.

Which Horses Are Most at Risk

Certain horses are far more sensitive to pasture sugars.

Higher-risk groups include:

• easy keepers

• overweight horses or ponies

• horses with cresty necks or fat pads

• horses with equine metabolic syndrome

• older horses with PPID

These horses do not need large amounts of sugar to trigger a problem.

Why Grass Is Not Consistent

One of the biggest misconceptions is that grass is always safe.

Sugar levels in pasture change based on:

• time of day

• weather

• season

• plant stress

For example:

• sugar levels rise throughout the day

• late afternoon and evening often have the highest levels

• stressed grass, such as during drought or frost, can contain higher sugar

This is why laminitis can appear suddenly even when management has not changed.

Why Time-Restricted Grazing Often Fails

Many owners try limiting turnout to a few hours per day.

The problem is:

• horses compensate by eating faster

• total sugar intake may stay the same or increase

Short periods of unrestricted grazing can still deliver a high sugar load.

The only relatively safer window is early morning, when sugar levels are lowest, but even this is not risk-free.

How Serious Is This?

Low Risk

• normal weight

• no history of laminitis

• controlled pasture exposure

What this means: routine monitoring is sufficient

Moderate Risk

• overweight

• early metabolic changes

• mild laminitis history

What this means: diet must be actively controlled

High Risk

• confirmed laminitis

• insulin dysregulation

• recurring episodes

What this means: strict dietary management is essential

Critical

• active laminitis episode

• significant pain or hoof instability

What this means: immediate removal from pasture and full dietary control

What To Feed Instead

The foundation of feeding a laminitis-prone horse is low sugar forage.

Low-NSC Hay

• ideally tested and below 10 percent NSC

• forms the base of the diet

Soaked Hay

• soaking can reduce sugar content

• useful when low-NSC hay is not available

Avoid

• grain

• sweet feeds

• molasses

• high-sugar treats

In practice, removing hidden sugars is one of the most effective steps.

Key Management Strategies That Actually Work

Remove or Strictly Control Pasture Access

Dry lot systems are often the safest option for high-risk horses.

Use Grazing Muzzles

These can significantly reduce intake while allowing movement and turnout.

Feed Smaller, More Frequent Meals

This helps reduce insulin spikes and stabilise metabolism.

Monitor Body Condition Closely

Target a moderate body condition.

Weight control is one of the most powerful tools in preventing laminitis.

Time Grazing Carefully

If grazing is allowed:

• early morning is the lowest-risk period

• avoid afternoon and evening turnout

Even then, caution is required.

Understanding Insulin Resistance

In horses with metabolic issues:

• the body produces more insulin than normal

• tissues respond poorly to insulin

• high insulin levels damage the laminae

This is why laminitis can occur even without obvious overfeeding.

Testing may include:

• fasting insulin levels

• oral sugar testing

Identifying this early changes management significantly.

What To Do Right Now

If your horse is at risk or has had laminitis:

• remove access to lush pasture immediately

• switch to low-NSC forage

• avoid all high-sugar feeds

• assess body condition honestly

• involve your vet if there are any signs of foot soreness

If there are signs of active laminitis, treat this as urgent and act immediately.

When Is This an Emergency?

Treat as urgent if:

• your horse becomes foot sore

• shifting weight or reluctance to move develops

• digital pulses increase

• heat is felt in the hooves

These are early signs that require immediate action.

Common Mistakes

• assuming grass is always safe

• relying only on time-restricted grazing

• underestimating sugar content in pasture

• ignoring weight gain

• delaying action after early signs

In practice, these are the exact reasons laminitis continues to occur.

Long-Term Prevention

Successful management focuses on:

• consistent diet control

• maintaining appropriate weight

• monitoring pasture conditions

• managing underlying metabolic disease

Laminitis is rarely random. It is usually predictable once you understand the risk factors.

Frequently Asked Questions

Can laminitis-prone horses ever graze safely?
Sometimes, but only under strict control. Many require permanent restriction during high-risk periods.

Is hay always safe?
Only if sugar levels are low. Testing or soaking may be needed.

Is night turnout safer?
Sometimes, but sugar levels can still rise depending on conditions. Early morning is generally safer.

Do grazing muzzles really help?
Yes. They can significantly reduce intake and are one of the most practical tools available.

Can weight loss reverse risk?
It can significantly reduce risk, especially in metabolic horses.

Final Thoughts

Feeding a horse with laminitis is not just about removing grain. It is about understanding how sugar intake affects the body and the hoof.

The key decisions are:

• how much sugar is being consumed

• when it is being consumed

• how the horse’s body is responding

When these are controlled properly, laminitis can often be stabilised and prevented from recurring.

If you are unsure whether your horse’s diet is truly safe or want help building a practical feeding plan, ASK A VET™ can guide you through the next steps with clear, case-specific advice tailored to your horse.