Equine Metabolic Syndrome: Managing Horses at Laminitis Risk

Equine metabolic syndrome is a hormonal disorder affecting insulin regulation and dramatically increasing laminitis risk, requiring lifelong dietary and management changes.

Key Facts

Equine metabolic syndrome involves insulin dysregulation, obesity, and abnormal fat deposits at the crest, tail head, and behind the shoulders
Insulin dysregulation is now recognized as the primary mechanism driving laminitis in EMS horses
Easy keepers and breeds including native ponies, Morgans, and Quarter Horses are at elevated risk
Diagnosis involves measurement of resting or post-feeding insulin levels, not just visual assessment of body condition
Pasture grass is dangerous for EMS horses due to high nonstructural carbohydrate content that spikes insulin
Weight loss through controlled diet and exercise is the cornerstone of EMS management
Some horses benefit from medication such as levothyroxine or metformin to support weight loss and insulin sensitivity
Dietary management requires soaking hay to leach sugars and avoiding grain, molasses, and lush grass

Welfare Considerations

Horses with EMS face a challenging welfare paradox: the very environments they enjoy, open pasture and ad libitum hay, are the greatest threats to their health. Without careful management, recurrent laminitis can cause chronic pain, rotation of the pedal bone, and ultimately euthanasia. Restricting horses from pasture can itself cause frustration and social isolation. Balancing metabolic management with behavioral needs requires creativity and commitment from owners. Horses with well-controlled EMS can live comfortable, active lives, but the disease demands ongoing vigilance. Failure to recognize EMS before the first laminitis episode represents a missed welfare opportunity that can have lasting consequences.

What You Can Do

Test any overweight easy-keeper horse for insulin dysregulation, especially before spring grass season
Soak hay for 30 to 60 minutes to reduce nonstructural carbohydrate content for EMS horses
Use a grazing muzzle or restrict pasture access during high-risk periods while maintaining social contact
Work with your vet to develop a safe exercise program that supports weight loss without laminitis flares
Monitor body condition score monthly and adjust feeding accordingly rather than relying on visual estimates