Equine Metabolic Syndrome, commonly called EMS, has become increasingly common among modern horses, especially easy keepers and lightly worked animals.

For many owners, managing EMS requires a complete shift in how they think about forage, body condition, and long-term nutrition.

Because hay represents the foundation of most equine diets, forage selection often becomes one of the most important parts of successful metabolic management.

What Is Equine Metabolic Syndrome?

EMS is a condition involving abnormal insulin regulation and increased metabolic sensitivity.

Affected horses are often prone to:

obesity,
regional fat deposits,
insulin dysregulation,
and increased laminitis risk.

Many EMS horses appear outwardly healthy until hoof soreness or weight gain becomes more obvious.

Because horses vary significantly in metabolic sensitivity, feeding programs should always be individualized.

Why Forage Matters So Much

Most horses consume hay for many hours each day.

Even relatively small differences in forage quality can influence:

calorie intake,
sugar consumption,
digestive stability,
and body condition.

For EMS horses, many owners prioritize:

consistent forage,
moderate calorie density,
clean hay,
and careful NSC management.

The goal is supporting healthy fiber intake while reducing unnecessary metabolic stress.

Understanding NSC

NSC stands for non-structural carbohydrates.

This includes sugars and starches naturally present within forage.

Some EMS horses experience exaggerated insulin responses when consuming elevated sugar intake.

Because of this, owners often seek hay with moderate or lower NSC values.

However, no single NSC target works perfectly for every horse.

The ideal feeding program depends on:

body condition,
insulin sensitivity,
activity level,
age,
and overall health.

Weight Management Is Central

Many EMS horses gain weight extremely efficiently.

Owners are often surprised by how few calories some easy keepers actually require.

Helpful practices frequently include:

weighing hay,
monitoring body condition regularly,
using slow feeders,
and adjusting intake gradually.

Small changes over time are often more sustainable than extreme restriction.

Consistency Reduces Nutritional Fluctuation

Frequent forage changes may complicate metabolic management.

Differences in:

digestibility,
calorie density,
and sugar levels

can influence how horses maintain weight and respond nutritionally.

Consistent forage allows owners to evaluate body condition changes more accurately and reduce feeding guesswork.

Predictable nutrition often creates more stable long-term management.

Digestive Health Still Matters

Owners sometimes become so focused on lowering calories that they accidentally choose forage that is overly coarse or poorly digestible.

Fiber quality still matters tremendously.

Horses require forage for:

digestive function,
hindgut health,
chewing behavior,
and emotional comfort.

Even lower-calorie hay should still be:

clean,
appropriately digestible,
and reasonably palatable.

Hay Testing Provides Valuable Information

Visual appearance alone cannot accurately determine forage sugars.

Laboratory testing can provide insight into:

NSC,
digestibility,
protein,
fiber,
and moisture.

For horses with significant metabolic sensitivity or previous laminitis history, forage analysis can help owners make more informed feeding decisions.

Exercise and Lifestyle Also Matter

Nutrition is only one part of EMS management.

When medically appropriate, movement and exercise may help support:

insulin sensitivity,
weight management,
and overall health.

Pasture access, stress levels, and seasonal management also influence metabolic stability.

Individualized Management Creates Better Results

No single hay works perfectly for every EMS horse.

Some horses thrive on carefully managed grass hay.

Others require stricter calorie control or more digestible forage.

Thoughtful feeding programs focus on:

consistency,
gradual adjustments,
digestive support,
and matching forage to the individual horse.

Long-term metabolic management is usually built through steady, sustainable decisions rather than drastic feeding changes.

FAQ

What is EMS in horses?

EMS stands for Equine Metabolic Syndrome, a condition involving insulin dysregulation and increased laminitis risk.

Should EMS horses eat low-sugar hay?

Many EMS horses benefit from careful NSC management and controlled calorie intake.

Why is body condition important in EMS?

Excess body fat may worsen metabolic sensitivity in susceptible horses.

Does hay testing matter for EMS horses?

Yes. Testing helps owners better understand forage nutrition beyond visual appearance.

For horse owners managing laminitis or founder-prone horses, few questions are more important than understanding the relationship between forage and metabolic health.

Many owners are surprised to learn that hay itself can sometimes contribute to nutritional challenges in susceptible horses.

While forage remains an essential part of the equine diet, the nutritional composition of hay can vary significantly, particularly when it comes to sugar and starch content.

Understanding these differences can help owners make safer, more informed feeding decisions.

What Is Founder?

Founder is commonly used to describe the painful structural damage that may occur following laminitis.

Laminitis involves inflammation and weakening within the sensitive tissues of the hoof.

In some cases, structural support inside the hoof becomes compromised, leading to rotation or sinking of the coffin bone.

Multiple factors can contribute to laminitis, including:

metabolic disease,
obesity,
insulin dysregulation,
grain overload,
systemic illness,
and pasture or forage management.

For many modern horses, especially easy keepers, nutrition plays a major role.

Hay Contains Natural Sugars

All forage contains naturally occurring sugars.

Plants produce sugars during photosynthesis and store energy for growth and survival.

When horses consume hay, they also consume those sugars.

Most healthy horses tolerate normal forage sugars without difficulty.

However, metabolically sensitive horses may struggle to regulate elevated sugar intake efficiently.

This is particularly important for horses with:

Equine Metabolic Syndrome,
Cushing’s disease,
obesity tendencies,
or previous laminitis history.

Sugar Levels Can Vary Tremendously

One of the biggest misconceptions in horse feeding is assuming all grass hay is nutritionally similar.

In reality, sugar levels may vary dramatically depending on:

forage species,
weather,
sunlight exposure,
plant maturity,
harvest timing,
fertilization,
and storage conditions.

Two visually similar bales may contain very different nutritional profiles.

This is why forage testing can be extremely valuable for owners managing sensitive horses.

Why Some Horses React More Strongly

Not every horse responds identically to forage sugars.

Some horses tolerate moderate NSC intake easily, while others appear highly sensitive.

Insulin dysregulation is a major factor.

When certain horses consume elevated sugar or starch levels, insulin responses may become exaggerated. Over time, this may increase laminitis risk in susceptible individuals.

This does not mean sugar is automatically dangerous for every horse.

It means that certain horses require more careful nutritional management.

Hay Selection Matters

Owners managing founder-prone horses often focus on:

moderate to lower NSC forage,
consistent hay quality,
clean, dust-free forage,
and controlled calorie intake.

Grass hays are commonly used because they may provide:

adequate fiber,
moderate energy density,
and consistent digestive support.

However, individual needs vary.

Some horses require stricter nutritional control than others.

Working with veterinarians and knowledgeable forage providers can help owners identify more appropriate feeding strategies.

Portion Control Is Also Important

Even relatively appropriate forage can contribute to weight gain if fed excessively.

Many easy keepers require fewer calories than owners expect.

Helpful management practices often include:

weighing hay,
monitoring body condition closely,
maintaining regular exercise,
and using slow feeders when appropriate.

The goal is balancing adequate forage intake with healthy body condition.

Restricting forage too aggressively may create additional digestive and behavioral stress.

Consistency Reduces Guesswork

Frequent forage changes can make metabolic management more difficult.

Consistent hay quality allows owners to better monitor:

body condition,
energy intake,
feeding behavior,
and overall nutritional response.

Many horses benefit from gradual transitions and stable feeding routines.

Predictability often becomes an important part of long-term management success.

Feeding the Individual Horse

There is no single feeding program appropriate for every horse prone to founder.

Age, workload, metabolism, body condition, and medical history all influence nutritional needs.

Thoughtful forage management can play a meaningful role in helping horses maintain comfort and long-term stability.

The focus should always remain on individualized feeding rather than relying on overly simplistic rules.

FAQ

Can hay sugars contribute to laminitis?

In metabolically sensitive horses, elevated sugar intake may increase laminitis risk.

Is all grass hay low in sugar?

No. Sugar levels vary significantly depending on harvest and growing conditions.

Should founder-prone horses avoid hay?

No. Horses still require forage for digestive and behavioral health.

What does NSC mean?

NSC refers to non-structural carbohydrates, including sugars and starches found in forage.

Hay Considerations for Equine Metabolic Syndrome