Equine Metabolic Syndrome Explained: Cresty Necks, Fat Pads, and Risk

Equine Metabolic Syndrome (EMS) is often misunderstood — and frequently oversimplified as “a fat horse problem,” but to many owners’ surprise, it can affect lean horses as well. In reality, EMS is a complex metabolic condition that increases a horse’s risk for laminitis, often without dramatic warning signs. Understanding how EMS differs from insulin resistance and Cushing’s disease is key to managing risk before irreversible damage occurs.

At Countryside Equine Hospital, EMS is approached as part of a broader metabolic picture, not a standalone label.

What Is Equine Metabolic Syndrome (EMS)?

EMS is not defined by a single blood test or hormone abnormality. Instead, it describes a pattern of metabolic dysfunction that includes:

• Abnormal fat distribution
• Increased inflammatory signaling
• Dysregulation of insulin— This differs from insulin resistance.
• Elevated laminitis risk

This is why EMS is referred to as a syndrome — a collection of clinical signs that tend to occur together rather than a single disease process.

EMS vs Insulin Resistance vs Cushing’s Disease

These three conditions are closely related but not identical.

Insulin Resistance (IR)

• Defined by elevated insulin levels and an increase in blood glucose
• Strongly linked to laminitis
• Can occur in thin or overweight horses

Cushing’s Disease (PPID)

• Caused by pituitary dysfunction
• Leads to excessive cortisol
• Often age-related
• Affects immunity, muscle, and metabolism

Equine Metabolic Syndrome (EMS)

• Defined by abnormal fat distribution and metabolic inflammation
• Often overlaps with insulin resistance
• Not driven by pituitary disease

A horse may have:

• One of these conditions
• Two of them
• Or all three simultaneously

This overlap is why early recognition of clinical signs and comprehensive testing matters.

Why Cresty Necks and Fat Pads Matter

Certain fat deposits are not cosmetic — they’re metabolically active.

Common EMS-associated fat deposits include:

• Cresty necks
• Fat pads behind the shoulders
• Fat along the tailhead
• Fat pads behind the eyes
• Topline muscle atrophy

These fat cells release inflammatory mediators that affect blood flow and tissue health throughout the body — including the hooves.

“When I see a cresty neck, I don’t automatically think Cushing’s. I think metabolic disease — and then we figure out which one we’re dealing with.”
— Dr. Dan Carter, Countryside Equine Hospital

This mindset prevents misdiagnoses and delayed intervention.

Fat as an Inflammatory Organ (Not Just Stored Energy)

One of the most important concepts in EMS is understanding that fat is hormonally active.

Fat cells:

• Release inflammatory signals
• Influence insulin regulation
• Affect blood vessel function

Once a threshold of fat storage is crossed, inflammation increases and laminitis risk rises sharply.

This explains why:

• Some horses develop laminitis without obvious dietary changes
• Weight alone doesn’t tell the full story
• Reducing fat mass is central to management

Body Condition Scoring: A Critical Skill for Owners

Body Condition Scoring (BCS) is one of the most valuable — and underused — tools for identifying EMS risk.

Key principles:

• Be honest, not optimistic
• Use hands, not just eyes
• Focus on neck, ribs, tailhead, and shoulders

Many EMS horses are described as “easy keepers,” but that term often masks creeping metabolic dysfunction. These horses often have a BCS of greater than 6 out of 9 — but don’t forget, EMS can occur in leaner horses too.

Food is not always love — and over-conditioning carries real medical consequences.

Why EMS Is a Diagnostic Puzzle

EMS may require multiple diagnostic tests if analysis of clinical signs are unrewarding. It is important to take the whole horse into consideration on exams and tests rather than simply relying on one blood test to confirm a diagnosis.

Veterinarians consider:

• Fat distribution patterns
• Body condition score
• Insulin levels
• History of laminitis or foot soreness
• Breed predisposition

There is more research to be done on EMS, but recognizing the clinical signs early and working with your veterinarian is key to managing your horse’s health.

Laminitis Risk and EMS

EMS significantly increases laminitis risk due to:

• Chronic inflammation
• Altered blood flow to the hoof
• Insulin dysregulation

Laminitis associated with EMS may:

• Develop gradually
• Be subclinical at first
• Worsen during spring and fall

This makes early identification and management essential.

Managing EMS: No Quick Fix, but Clear Direction

EMS management focuses on long-term lifestyle changes, not just medication alone.

Core management strategies include:

• Weight reduction through controlled diet
• Forage-first feeding plans
• Low-NSC ration balancers
• Elimination of unnecessary concentrates
• Structured exercise when safe

In some cases, medications used for insulin resistance may be temporarily needed — but lifestyle management is the foundation.

Exercise: Reducing Fat Cells Over Time

Exercise plays a central role in EMS management.

Physiologically:

• Sustained exercise mobilizes fat stores
• Reduces inflammatory fat mass
• Improves insulin sensitivity

Even moderate activity — when performed consistently — can help reduce metabolic risk over time.

Early detection is critical! Once laminitis occurs, exercise may no longer be an option. Always consult your veterinarian for exercise recommendations as part of your horse’s care plan.

Breed and Genetic Considerations

Certain breeds are more predisposed to EMS due to metabolic efficiency.

Common examples include:

• Ponies
• Gaited breeds
• Easy-keeping stock types

These horses evolved to thrive on minimal nutrition — which becomes a disadvantage in modern management environments.

When Should EMS Be Considered?

EMS should be evaluated when:

• A horse gains weight easily
• Cresty necks or fat pads appear
• Laminitis occurs without clear cause
• Insulin resistance is identified
• A horse struggles to lose weight despite dietary changes and/or increased exercise

By maintaining a Veterinary-Client-Patient Relationship (VCPR), you are better able to work with your veterinarian to monitor changes in your horse during annual or biannual exams.

EMS Is Manageable — If It’s Recognized

EMS doesn’t mean a horse can’t live a healthy, comfortable life. It does mean management must be intentional, informed, and consistent.

Early recognition allows owners and veterinarians to:

• Reduce laminitis risk
• Improve long-term soundness
• Preserve quality of life

Commonly Asked Questions

What is Equine Metabolic Syndrome?
EMS is a metabolic condition characterized by abnormal fat distribution, inflammation, and increased laminitis risk.

Is EMS the same as insulin resistance?
No. EMS often includes insulin resistance, but the two are not identical.

Does a cresty neck always mean Cushing’s disease?
No. Cresty necks are more commonly associated with EMS and insulin resistance.

Can EMS cause laminitis?
Yes. EMS significantly increases laminitis risk due to inflammation and metabolic dysfunction.

Can EMS be cured?
EMS cannot be cured, but it can be effectively managed through diet, exercise, and long-term lifestyle changes.

If you found this article helpful and want to experience compassionate, diagnostically-driven equine care, Countryside Equine Hospital is the place for you. Locally owned and privately operated, we’ve been proudly serving our local community since 1991. With integrity at the heart of our care, we deliver progressive medicine and exceptional service

Do you have an equine medical question or concern? We’re here for your horse day and night, offering 24/7/365 emergency care when it matters most. Give us a call at (770) 787‑4711 or visit us at 3395 Maughon Road, Covington, GA  30014. You can also learn more  and request an  appointment on our website at countrysideeq.com.

Published By

Dr. Rachel Akin