Insulin is a hormone that is produced by the pancreas and is responsible for making glucose available to the body's cells. Without insulin, glucose levels in the blood are very high and diabetes develops. Today on Texas Vet News I am going to talk about insulin in horses. Diabetes is very rare in horses but many horses are resistant to insulin. Even if there are normal or even increased levels of insulin, they are ineffective in some horses. Insulin resistance is common in many ponies, Paso Finos, and Morgans but all breeds can be affected.

Since high insulin levels have been determined to be related to laminitis or founder, it is important to know if your horse is insulin resistant. You can get an idea of insulin resistance just by looking at your horse. These horses are overweight but are not being over fed. They have fat deposits in unusual areas, such as the crest of the neck and around the tailhead. To diagnose insulin resistance, you can begin by having your vet check insulin and glucose levels on your horse after a 6-hour fast. Although this test is not 100 percent, it is a good screening test. If you are still unsure, a combined glucose insulin test can be performed. This test requires that insulin and dextrose be given to the horse in the vein and then glucose levels are checked about every 15 minutes for 2.5 hours. Although the combined glucose insulin test is a little more involved and a little more expensive than the 6-hour fast test, it can be performed by most vets and will let you know if your horse is resistant to insulin. If so, a specific diet will be required to help prevent your horse from developing laminitis.