Some horses seem to gain weight just by looking at a bale of hay.
We call them easy keepers, and while it’s often said with a smile, carrying extra weight can sometimes signal a much bigger issue. Equine Metabolic Syndrome, or EMS, has become one of the most important health concerns horse owners need to understand because of its strong connection to laminitis.
The good news is that early recognition and proper management can make a tremendous difference.
More Than Just an Overweight Horse
One of the biggest misconceptions about EMS is that it’s simply a weight problem.
While many horses with EMS are overweight, not every overweight horse has EMS, and not every horse with EMS appears obese. Some horses develop distinct fat deposits in specific areas, even when the rest of their body condition seems relatively normal.
Common places to watch for unusual fat accumulation include:
- Along the crest of the neck
- Above the eyes
- Around the shoulders
- Over the loin area
- Around the tailhead
- Near the mammary or sheath area
These changes can sometimes develop gradually, making them easy to overlook.
Understanding the Link to Laminitis
What makes EMS particularly concerning is its connection to insulin resistance and laminitis.
In horses with insulin resistance, the body becomes less effective at responding to insulin. As a result, insulin levels rise, creating metabolic changes that can increase the risk of laminitis.
Unfortunately, early laminitis isn’t always dramatic.
Many owners initially describe the horse as simply being “a little sore” or “not moving quite right.” By the time obvious lameness develops, significant damage may already be occurring.
That’s why recognizing the warning signs early is so important.
Who Is Most at Risk?
EMS can affect horses of many breeds and ages, but certain horses appear more predisposed than others.
Ponies, Morgans, Arabians, Paso Finos, and other easy-keeping breeds are commonly associated with the condition. Most cases occur in horses between about eight and eighteen years of age, although younger and older horses can also be affected.
If your horse tends to gain weight easily, it’s worth paying close attention to body condition and metabolic health.
Early Diagnosis Matters
One of the challenges with EMS is that owners often don’t realize there’s a problem until laminitis occurs.
Veterinarians diagnose EMS by combining physical examination findings with blood work and, when necessary, hoof radiographs to evaluate for laminitis.
The earlier EMS is identified, the better the chances of avoiding serious complications.
And honestly, prevention is always easier than rehabilitation after repeated laminitic episodes.
Management Starts with Lifestyle Changes
For many horses, EMS management comes down to two key factors: diet and exercise.
A forage-based feeding program, careful control of sugar and starch intake, and maintaining a healthy body condition are often central parts of treatment. Many horses also need restricted pasture access, especially during periods when grasses are particularly rich.
Regular exercise helps improve insulin sensitivity and supports healthy weight management.
Of course, horses already suffering from laminitis should only begin an exercise program under veterinary guidance.
Prevention Is Easier Than Treatment
One thing veterinarians consistently emphasize is that maintaining a healthy weight is far easier than reversing metabolic disease after it develops.
Regular exercise, thoughtful feeding practices, and routine veterinary evaluations all help reduce risk.
And while it can be tempting to spoil those easy keepers with extra feed because they always seem hungry, keeping them lean and active may be one of the best gifts we can give them for long-term health.
Sometimes the horses that look easiest to care for are the ones that require the most careful management.
Board-Certified Internal Medicine Specialist, Large Animal Pilchuck Veterinary Hospital. Dr. Wendy Harless Mollat grew up in Bend, Oregon, where she was actively involved in riding and training hunter/jumper and dressage horses. She graduated with her DVM from Oregon State University in 2002 and went on to complete a one-year internship in equine medicine and surgery at Pilchuck. Dr. Mollat followed her internship with a three-year residency in large-animal medicine at UC Davis and became board-certified by the American College of Veterinary Internal Medicine. In September 2006, Dr. Mollat returned to Pilchuck, where she now leads the equine referral hospital. Her areas of focus include biosecurity, neurological diseases, neonatology, equine gastric ulcer syndrome, and camelid (alpaca and llama) medicine.
