what is ems in horses

Equine metabolic syndrome (EMS) is an endocrine condition that affects horses and ponies. It is characterized by three main features: obesity or regional adiposity, insulin dysregulation, and laminitis. Horses with EMS tend to become obese very easily, depositing fat in the crest, shoulders, loin, above the eyes, around the tail head, and the mammary glands or prepuce, even when the rest of the body appears to be in normal condition. Some horses may have regional adiposity, and others may even appear normal weight, so obesity is not a definitive clinical sign of a horse with EMS. Laminitis is a major part of EMS, which is a crippling disease caused by weakening of the tissues anchoring the hoof wall to the bone. Horses with EMS can experience mild episodes that are not easily recognized, especially if the horses are not exercised regularly. EMS is a result of genetic predisposition combined with environmental and physiological factors such as obesity, high sugar diets, lack of exercise, and concurrent illnesses. Horses and ponies with EMS are often described as being “easy keepers” and have a tendency to become overweight. Noticeable fat pads may develop over the neck crest, tail head, shoulders, and around the mammary glands or prepuce. Most horses are 5–15 years of age when they develop laminitis that can be attributed to EMS. The diagnostic tests presently recommended for diagnosis and follow up of EMS are insulin, the Oral Sugar Test (OST), and Leptin.