Easy keepers—horses that remain rotund despite restricted diets and rigid exercise plans—must be managed carefully to prevent or minimize more serious health issues. Equine metabolic syndrome (EMS), one condition associated with obesity, can have a serious negative impact on horses’ health. Fortunately, over the past few years, veterinarians have made great strides in diagnosing and managing the disorder.

“Complex genetic tendencies interact with the environment to drive development of equine metabolic syndrome (EMS),” reported Ray Geor, BVSc, PhD, Dipl. ACVIM of Michigan State University’s College of Veterinary Medicine. He addressed a veterinary audience at the 2013 American Association of Equine Practitioners’ Convention, held Dec. 7-11 in Nashville, Tenn.

Geor said that certain breed of horses and ponies appear to be predisposed to developing EMS, including Morgans, Andalusians, Paso Finos, Arabians, Saddlebreds, Tennessee Walking Horses, and Welsh ponies. On the other hand, he said, other breeds tend to be at a lower risk, including Thoroughbreds, Standardbreds, and Quarter Horses.

Horses with EMS tend to possess a body condition score of 7 to 9 on a 9-point scale; for reference, a body condition score of 1 represents an emaciated horse, where 9 represents an obese horse. Often, EMS horses have a noticeably cresty neck and localized fat deposits, especially around the sheath or mammary tissue. However, not all affected animals are markedly obese or show evidence of abnormal fat accumulations; this means that the presence or absence of obesity cannot be used as the sole criterion for diagnosis of EMS, Ge