Are All Obese Horses At Risk for EMS Development? Maybe Not

One researcher says it’s unlikely that every obese horse is at risk of developing EMS and laminitis.

Scientists have long considered obesity to be a primary driver of equine metabolic syndrome (EMS). If this is true the horse industry is facing a very big problem; in a recent study of 300 horses in Virginia, researchers found that 51% of them were obese. That means more than half the country’s horse population is at risk of EMS and, thus, laminitis, right? Not so fast.

Ray Geor, BVSc, PhD, Dipl. ACVIM, a professor and researcher at Michigan State University (MSU), presented an overview of recent EMS research at the 2013 International Equine Conference on Laminitis and Diseases of the Foot, held Nov. 1-3 in West Palm Beach, Fla. In particular, he discussed a recent study headed by researchers at the University of Minnesota (Nichol Schultz, DVM; Molly McCue, DVM, MS, PhD, Dipl. ACVIM; and Krishona Martinson, PhD) in collaboration with MSU (Geor) and Tufts University (Nicholas Frank, DVM, PhD, Dipl. ACVIM). With this study they aimed to better define the physical and metabolic characteristics of EMS in an effort to better diagnose, manage, and prevent the disease and associated laminitis cases.

The first EMS feature of Geor described was insulin resistance (IR), a reduction in a horse’s sensitivity to the hormone insulin that makes it harder for cells to transport glucose (sugar) out of the bloodstream and store it as glycogen (energy).

"Although our understanding of the etiology and pathophysiology of EMS is far from complete, it seems likely that IR and/or associated hyperinsulinemia play an important role," he said. He cited a number of studies in which researchers have shown hyperinsulinemia, or exaggerated increases in blood insulin levels to feeding, to be a feature of the EMS phenotype (physical traits) in ponies and

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Written by:

Alexandra Beckstett, Managing Editor of The Horse and a native of Houston, Texas, is a lifelong horse owner who has shown successfully on the national hunter/jumper circuit and dabbled in hunter breeding. After graduating from Duke University, she joined Blood-Horse Publications as Assistant Editor of its book division, Eclipse Press, before joining The Horse.

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