Insulin Resistance in Horses
When a horse eats, its body metabolizes food into glucose which travels through the bloodstream to various tissues throughout the body where it is used for energy. Insulin is a hormone produced by the pancreas that allows glucose in the blood to enter the tissue cells for utilization. If the tissue cells lose sensitivity to insulin, the glucose can no longer effectively provide energy to the horse. This syndrome is called Insulin Resistance. It commonly occurs in horses that are consuming too much sugar & starch because they are flooding their body with too much glucose and eventually the insulin becomes ineffective. Since the peripheral tissue is not using the glucose, the horse becomes hyperglycemic and throws off the balance of fluid in the body causing increased drinking, urinating, and then dehydration.
Signs that your horse is insulin resistant include fatty deposits on the crest of the neck, the rump, and above the eyes as well as chronic laminitis. Your vet will be able to diagnose insulin resistance by increased blood insulin levels. Advanced symptoms include the increased thirst and urination along with decreased muscle mass and lethargy.
If your horse is insulin resistant you should restrict the sugar, starch and fat in their diet and increase their exercise to help them lose weight. Be sure to evaluate the horse’s mineral intake to ensure it is balanced and still provide hay because too drastic of a diet change can make the condition worse.