Managing Equine Endocrine Disorders: A Horse Owner’s Guide to Cushings and Metabolic Syndrome

Endocrine disorders like Cushing’s disease and Equine Metabolic Syndrome (EMS) are common in aging horses—and if left unmanaged, they can lead to serious health complications, including laminitis, weight loss, and a decline in quality of life.

At Lewiston Veterinary Clinic in Lewiston, ID, we specialize in equine medicine and understand the unique challenges these conditions present. This guide is designed to help horse owners recognize early signs, understand available treatments, and take proactive steps to support the health and longevity of their horses.

Understanding Equine Cushing’s Disease (PPID)

What It Is:
Equine Cushing’s disease—more accurately termed Pituitary Pars Intermedia Dysfunction (PPID)—is a chronic hormonal disorder caused by the degeneration of nerves in the brain that control the pituitary gland. This degeneration leads to excess production of cortisol and other hormones, disrupting your horse’s metabolism and immune system.

Who’s at Risk:
Cushing’s is most often diagnosed in horses over the age of 15, but it can occur earlier. Ponies and certain breeds like Morgans and Arabs may be predisposed.

Common Symptoms:

Long, shaggy or curly hair coat that doesn’t shed properly (hirsutism)
Increased drinking and urination
Muscle wasting, especially along the topline
Pot-bellied appearance
Lethargy or dullness
Laminitis, often recurrent or unexplained

For a deeper dive into the condition, visit Pituitary Pars Intermedia Dysfunction (PPID) – UC Davis Veterinary Medicine.

What Is Equine Metabolic Syndrome (EMS)?

EMS is a condition characterized by insulin resistance, abnormal fat deposits, and a heightened risk of laminitis. It’s often confused with—or occurs alongside—Cushing’s, but the underlying causes and management strategies differ.

Key Signs of EMS:

Easy weight gain or obesity
Cresty neck, fatty deposits over shoulders or tailhead
Laminitis episodes, sometimes without warning
Elevated insulin or glucose levels

EMS is most commonly seen in easy-keeper breeds, especially ponies, Morgans, and Arabians.

What Causes These Endocrine Conditions?

Age and Genetics

Horses over 15 years are more prone to PPID
Breeds such as ponies, Morgans, and Arabians may be more genetically susceptible

Diet and Exercise

High-sugar or starch-rich diets contribute to insulin resistance
Lack of exercise and excess body condition also increase risk

For dietary advice specific to horses with Cushing’s, see What Should I Feed My Horse with Cushing’s Disease? – Purina

Diagnosing PPID and EMS

At Lewiston Veterinary Clinic, we use a combination of clinical exams, blood tests, and history to make an accurate diagnosis.

Common Diagnostic Tools:

ACTH Test: Measures hormone levels to confirm PPID
Insulin and Glucose Tests: Detect insulin resistance associated with EMS
Physical Exam: Looks for fat distribution, laminitis, coat changes, and muscle condition
Imaging and Lab Tests: Help assess complications such as laminitis or infections

For more, visit Equine Cushing’s Disease Diagnosis – Royal Veterinary College

Treatment Options for Endocrine Disorders

Managing Cushing’s Disease

Pergolide (Prascend): The most commonly prescribed medication to help normalize hormone levels
Clipping: Horses with PPID often benefit from seasonal body clipping to stay cool and comfortable
Regular Dental and Hoof Care: These horses are more prone to infections and laminitis

Explore case-based treatments at Cushing’s Disease – The Horse

Managing Equine Metabolic Syndrome

Dietary Management: Low-sugar, low-starch diets with quality forage
Weight Loss: Target a slow, controlled reduction through portion control and exercise
Grazing Muzzles: Can help restrict access to lush pasture without limiting turnout
Regular Exercise: Even light exercise improves insulin sensitivity

Preventing and Managing Long-Term Risks

Both PPID and EMS can be managed successfully with the right care. Prevention and monitoring are essential.

1. Monitor Diet Year-Round

Use a hay analysis if needed to gauge sugar content
Avoid sweet feeds or treats high in starch
Feed by weight, not volume

2. Control Grazing

Avoid turnout during peak grass growth (early mornings and spring flush)
Use grazing muzzles if needed

3. Prioritize Hoof Care

Horses with PPID and EMS are very prone to laminitis
Schedule trims every 4–6 weeks
Watch for subtle signs like shifting weight or reluctance to move

4. Stay Ahead with Regular Checkups

Routine exams can catch issues early before complications arise. Learn more about preventive care at our Equine Wellness Care page.

When to Contact a Vet Immediately

Certain symptoms signal the need for urgent evaluation:

Sudden lameness or signs of laminitis
Severe weight loss
Uncontrolled thirst and urination
Lethargy or behavior changes
Non-shedding winter coat into spring

We’re Here for Every Stage of Your Horse’s Life

Whether you’re monitoring your senior gelding for PPID or managing a younger horse with metabolic concerns, our team is here to support you with:

Accurate diagnosis and treatment plans
Nutritional and management advice
Hoof care coordination and emergency support
Preventive wellness exams tailored to endocrine health

If you suspect your horse may be developing Cushing’s disease or metabolic syndrome, don’t wait. Early diagnosis and careful management are key to long-term health.