EMS (Equine Metabolic Syndrome) in horses

EMS (Equine Metabolic Syndrome) in horses

 EMS is a condition that is difficult to treat and can be classified as an equine welfare disease. Here you can read more about which horses are affected by EMS, what the symptoms are and what the prognosis is for those horses that fall ill.

EMS in horses - what is it? 

EMS, which stands for equine metabolic syndrome, is the inability of a horse to regulate its insulin levels in response to feed intake. This is also referred to as insulin dysregulation (ID). Although overfeeding and under-exercising are common in the development of EMS, not all overweight horses suffer from equine metabolic syndrome, just as not all horses suffering EMS are overweight.

The underlying causes are complex and not fully understood. Ponies and smaller breeds tend to be more susceptible, suggesting a genetic predisposition. Horses that develop EMS have high insulin and glucose levels and are at high risk of developing laminitis.

What causes EMS?

Horses with EMS suffer from disturbed carbohydrate and fat metabolism with insulin dysregulation. Symptoms are easy to miss initially, and clinical signs of EMS vary, which often makes it difficult for horse owners to detect the disease early.

Typical symptoms of EMS in horses

• Obesity: fat deposits on various parts of the body, for example, above the eyes, on the withers, shoulder, neck, belly and around the stem of the tail. Despite diet, it can be difficult for the horse to lose weight.
• Laminitis: Due to the sharp rise in blood sugar levels, horses with EMS are at increased risk of laminitis.

Diagnosis

There are several different tests to diagnose EMS.

• Blood test: a vet takes a blood sample to measure insulin and glucose levels, but the test does not give a 100% indication of insulin metabolism. This is because stress, the horse's condition and feeding can affect the results.
• Oral glucose tolerance test (OGT): The horse is given a specific amount of glucose syrup orally by a vet, and blood glucose and insulin levels are then measured and re-measured to assess how well the horse can absorb glucose.
  

How to treat EMS in horses

All horses with EMS must follow a strict diet and exercise regime. To lose weight, a horse’s energy intake should be reduced gradually.

• Hay or haylage can be soaked for at least 30 minutes before feeding, to reduce the content of water-soluble sugars.
• Stop feeding concentrates (most concentrates contain high levels of sugar/starch).
• Turnout needs to be extremely limited
• Avoid treats that are high in sugar/starch.
• Regular exercise is important as it increases the horse's metabolism and helps with weight loss.