Insulin Resistance in horses – what is it?

What is insulin resistance in horses?

Insulin resistance in horses, or IR for short, is the failure of tissues to respond appropriately to insulin. A hormone secreted by the pancreas, insulin is released when blood sugar (glucose) is high—such as after eating—to stimulate the uptake of glucose by tissues and maintain proper levels of glucose in the body. When tissues do not respond appropriately to insulin the pancreas secretes even more, leading to elevated levels of insulin in the blood or hyperinsulinemia. Together, IR and hyperinsulinemia are referred to as “insulin dysregulation,” which simply means an excessive insulin response to blood sugar.

What can be done about it?

IR or insulin resistance doesn’t really cause observable signs in and of itself, but as a component of Equine Metabolic Syndrome and a complication of Cushing’s, it can lead to serious issues such as obesity and laminitis. The first step is getting a diagnosis, which can be easily and accurately done right where the horse lives with a simple blood test done by your veterinarian. The Oral Sugar Test only requires the veterinarian to draw blood twice, 30 minutes apart, in the morning after limited hay (and no grain). If blood levels of insulin (and glucose) are high, the vet may wish to perform further diagnostic tests to get to the root of the problem.

What else do I need to know about insulin resistance in horses?

Once a horse is diagnosed with either Equine Metabolic Syndrome or Cushing’s, the vet will work with the owner to develop a treatment plan which may include prescription medication, dietary management  or a feed change, recommendations for turnout/exercise, and the use of supplements. Vitamin E and other antioxidants are necessary for the oxidative stress associated with both these disorders while chromium, magnesium, and other ingredients support proper insulin function.