The Truth Behind Your “Easy Keeper” – Equine Metabolic Syndrome
All horse people know what an “easy keeper” is: a horse that resembles an LP tank on legs and seems to get fat eating nothing but air. The truth is, an “easy keeper” isn’t just a cute chubby horse anymore. It is actually a horse with a very serious disease called Equine Metabolic Syndrome and leaves horses very susceptible to developing a variety of health problems including laminitis (founder).
Obesity is a very common medical problem affecting the modern horse world today. Horses are being fed high-calorie diets that are horribly excessive in relation to their actual dietary needs and physical activity levels. Horses evolved as grazing herbivores with forage (wild and native grasses) as their main energy source. Horses developed a survival mechanism to be able to use their dietary intake very efficiently during periods of environmental stress (winter, drought). However, when thrown too many calories in combination with reduced physical activity (stall confinement), horses can quickly become “easy keepers”.
Horses that suffer from Equine Metabolic Syndrome (EMS) are those that have excess body fat that develops in “classic” locations along the crest of the neck, over the withers and tail head, and in the sheaths of geldings and stallions. Mares suffering from EMS will often have very irregular heat cycles and be difficult to get pregnant. Why is this extra weight so dangerous?
These extra fat cells are more than just unsightly to look at. Research is now showing that these fat cells actually secrete hormones that interfere with a variety of processes in the horse’s body including insulin secretion. Horses affected with EMS have persistently elevated blood sugar levels because certain hormones secreted by the fat cells decrease the action of insulin and make the horse insulin resistant and unable to regulate its blood sugar level. Body tissues that are not used to this elevated blood sugar are damaged over time. These hormones also interfere with blood pressure regulation and blood flow to tissues. Altered blood flow (often decreased) is thought to be responsible for why these horses are at risk for the development of laminitis (founder).
The concept behind treating the disease is simple though the results often aren’t: less calories and more exercise. This is often difficult to do, as many times this condition isn’t recognized until the horse has already developed laminitis or front-end stiffness and is too painful to be exercised. The best thing to do is to closely watch the weight of your horse and what you are feeding him to prevent the problem before it occurs.
Due to the condition of insulin resistance, horses with EMS are very sensitive to sugar and starch and the key is limiting the soluble carbohydrate content of the diet. Taking grain products out of the diet and switching to a hay only feeding regimen has improved horses comfort with laminitic pain in a matter of a few days. Forbidden food includes any kind of grain or concentrate, apples, carrots, wheat bran, molasses/sweet feeds, and fresh grass. Hay for horses with EMS should ideally contain less than 10% sugar and starch. The sugar content of hay is influenced predominantly by the growing stage/condition when it was cut and the drying process, and not necessarily by the type of hay. Fresh grass always contains more sugar than hay as the stored sugar is used during the drying process. Horses with EMS can be turned out on pasture for exercise as long as they are wearing a grazing muzzle and are prevented from eating grass. The best way to determine if the hay is suitable is to have it analyzed by a laboratory for the carbohydrate content and work directly with a veterinarian or nutritionist to develop a feeding program individualized for your horse for safe weight reduction and management.