How to manage EMS in horses

Does your horse struggle with occasional bouts of laminitis? Is he fat? Have you had him tested for insulin resistance and found out that he tested positive? If you answered in the affirmative to any or all of these questions, you may have a horse suffering from EMS or Equine Metabolic Syndrome on your hands. This condition is becoming increasingly common in the U.S., as horse owners fail to take the steps necessary to restrict their horses feed intake and overall weight. However, EMS is manageable and your horse can still enjoy a productive and healthy life.

How to Identify EMS in Horses, Correctly.

Ponies with EMS
Ponies are prone to EMS

According to many medical researchers, EMS is considered a genetic disorder. Certain equine breeds, such as: Paso Finos, Arabians, Morgans and a number of pony breeds appear to be predisposed to the condition. It is typically observed in horses and ponies between the ages of 5 and 15 years of age.

New cases of laminitis in horses and ponies diagnosed with EMS tend to occur in the spring. During spring time, pasture grasses tend to have higher sugar levels, resulting in higher levels of glucose and insulin circulating in the horse's bloodstream. This increase can antagonize the horse's existing insulin resistance issues, potentially increasing its risk of laminitis. Bear in mind, just allowing horses to graze is not typically a problem if there is no underlying endocrine problems.

EMS is usually diagnosed based on blood tests, hoof radiography to check for laminitis and clinical review. However, the presence of laminitis, insulin resistance and obesity, individually or in combination, are often strong indications of Equine Metabolic Syndrome. Note that not all horses with EMS are obese and that not all obese horses have EMS. Laminitis episodes are usually the first indication of EMS. Insulin resistance, which is where the horse has high blood insulation concentrations and a decreased tissue response, are usually the 3rd leg of an EMS diagnosis. Your veterinarian should take care to rule out other endocrine issues, such as Cushing's disease.

Managing Horses Diagnosed with EMS.

Limiting the severity and frequency of laminitis episodes is most successful when EMS is detected and treated as soon as possible. Multiple bouts of laminitis can cause the hoof laminae to be so structurally damaged that the horse's prognosis becomes increasingly negative . Managing the horse's diet is critical to EMS management. Here are some ways to fuel your horse's weight loss in a healthy fashion:

  • Feed your horse a lower calorie diet, but, don't overly restrict the horse's diet to the point where he gets overly bored.
  • Feed your horse "late maturity" hay.
  • Avoid sweet feed, grain and treats.
  • Don't allow obese horses to be pastured, as uncontrolled calorie intake must be avoided.
  • A pound per day of ration balancer can help to insure the horse's nutritional needs are met.


Between 1.2% and 1.3% of the horse's body weight is a good way to determine the right amount of hay to feed a horse on a calorie restricted diet. Look for hay where the nonstructural carbohydrate content (starch and ethanol soluble carbohydrates) is less that 10%. As your horse starts to lose weight, the insulin resistance is likely to improve. Consider having your vet track blood serum insulin levels to accurately evaluate your horse's progress. Once an EMS horse has lost the weight and gotten insulin resistance on a more normal track, some grazing may be allowed. Discuss advisable pasture management strategies with your vet. While physical exercise is important for managing EMS, this may be an issue in horses with laminitis based foot damage.

Once the horse is able, try to work the horse for 15 minutes a day, 3 to 4 days per week. Workout lengths should be gradually increased as the horse's conditioning improves. A sand arena with even and not over deep footing might be advisable at this stage. Carefully observe the horse's feet to make sure no new signs of hoof issues or laminitis surface. Horses not ready to be ridden should be turned out, so they can move and play around.

Some veterinarians prescribe medications such as levothyroxine sodium for horses who have been severely impacted by EMS and where strict dietary control does not sufficiently control subsequent laminitis episodes. Medical therapy should be used in conjunction with other dietary and exercise management strategies. While there are any number of nutritional supplements on the market claiming to be effective in aiding EMS horses, discuss the benefits with your veterinarian before adding anything new to your horse's diet.

While EMS cannot be cured, your horse's overall well being, health and episodes of laminitis can be managed through critical changes in diet and lifestyle. Laminitis is the biggest issue with this condition and the horse's prognosis will depend to a large degree on "sinking" or rotation of the coffin bone at the time the horse is diagnosed.