By: Dr. Lydia Gray
Horses that score 7, 8 or 9 on the 9-point Henneke Body Condition Scoring Scale are considered overweight. Carrying too much weight can lead to problems such as laminitis; more strain on feet, joints and limbs; increased stress on heart and lungs; lethargy and fatigue; and less efficient cooling. Ponies and some breeds of horses are "easy-keepers" and prone to being overweight, but this doesn’t mean they have to be.
A weight reduction program in horses includes diet, exercise and close observation. Replace all grain with a ration balancer or multi-vitamin/mineral supplement. Feed grass hay at a rate of 2% of the current body weight and gradually reduce this to 1.5%. Limit grass (pasture) and treats. Ride, lunge, drive, or handwalk rather than rely on free-choice exercise. Every two weeks, estimate and record the body condition score and weight of the horse. Weight can be estimated by a commercial weight tape or by using a weight calculator formula.
Some horses may be overweight due to Equine Metabolic Syndrome—a syndrome of obesity, insulin resistance and laminitis in middle-aged horses. Cresty-necked horses or those having trouble losing weight should be examined by a veterinarian for EMS. In addition to proper diet and exercise, the prescription medication levothyroxine sodium (Thyro-L supplements such as chromium and magnesium may help manage the condition.) and