Instructions
Read the tag on the feed bag to determine the amount of sugar in commercial feed. Test hay and grass to complete feed analysis. Samples of each feed source can be brought to a veterinarian for testing. Determining how much sugar is actually being consumed will be helpful when diagnosing other symptoms.
Look for changes in behavior. Hyperactivity is a common sign of too much sugar in the diet. A horse with low to moderate activity cannot properly utilize the consumed feed. After a grain meal, the horse's blood sugar level rises and the horse may act nervous, unmanageable or even dangerous. Feeding a diet higher in fat can help by stabilizing the horse's blood sugar level.
Watch for abdominal discomfort. A horse suffering from colic or abdominal pain could be reacting from a diet too high in sugar. When food moves through the digestive tract too fast, proper digestion and fermentation can not occur. Signs of colic include lying down more than normal or getting up and lying down repeatedly. Additional signs are standing stretched out, standing poised as if to urinate, looking at sides, pawing the ground, kicking at the abdomen (stomach) or rolling.
Check the horse for soreness or heat in the hoof. Laminitis, or founder, can also result from improper digestion. In most cases, both front feet will be sore. Rear feet can be involved but not as often because the front feet bear more weight than the rear feet. The stride of the horse will be shorter, and the horse may appear stiff. When resting, the horse may stand with front feet pushed forward, shifting its weight to the rear. A horse suffering from founder may shift its weight from one front leg to the other or spending a lot of time lying down.
Test for insulin resistance. Insulin is a hormone that signals the body's cells to absorb glucose (blood sugar). When the cells become resistant to the effects of insulin, more insulin is secreted and blood sugar levels rise abnormally high. This is known as diabetes. Horses suffering from diabetes may appear overweight or have unusually large amounts of edema or inflammation. In later stages, the horse may lose weight and muscle mass due to the inability to process glucose.
Evaluate the horse for other metabolic disorders, such as PSSM (polysaccharide storage myopathy). Horses with PSSM have an excessive amount of stored glucose. Symptoms include muscle and cell damage, stiffness, difficulty rising, exhaustion, sore back, bad attitude, muscle tremors, kicking out, tail swishing, looking at belly, lameness or abnormal movement or rhabdomyolysis (destruction of muscle cells), known as tying up. Consult a veterinarian to assist with adjusting the feed regimen.
How to Identify a Horse With Too Much Sugar in the Diet
Horses of different ages and exertion levels have significantly different feed and nutrition requirements. Many grain- and pellet-based diets have been formulated for horses performing tasks that require additional caloric intake. Many of these commercial feeds as well as hay and grass contain sugar. Too much sugar in the diet, regardless of activity level, is enough to cause problems. Combine too much sugar and a sedentary horse, and even more problems can arise. Behavioral changes, sickness and disease can be signs of too much sugar.