Is Insulin Resistance the Only Cause of Laminitis?
No. The tendency to treat laminitis by switching to a low starch feed, removing your horse from pasture, and taking away the carrots and apples as treats, is the first approach most horse owners will take. Certainly, insulin resistance (typically resulting from obesity, metabolic syndrome, and equine Cushing’s disease) is the main cause of this debilitating condition, and reducing the sugar and starch content in the diet is the best way to lower circulating insulin levels. But if you’re not certain of the cause, rule out the following before making dramatic changes.
Carbohydrate overload from overconsumption of starchy feeds. You might be thinking, “Isn’t this the same thing as what happens with insulin resistance?” Actually, it’s an entirely different cause. If you feed a very large meal made from cereal grains (oats, corn, barley, etc.), the grain can reach the hindgut where the bacterial flora will ferment starch to lactic acid. The resulting bacterial destruction causes the release of endotoxins, which enter the bloodstream, leading to laminitis. This is a very different mechanism than elevated insulin. The problem is not consuming starch; the problem is consuming too much at one time.
Physical stress to feet. Poor farrier care, no barefooted rest periods, walking on a hard surface, trailering during the summer, or injury to one limb, causing increased weight on the healthy limbs, can all lead to laminitis.
Infections and illness. Antibiotic usage for a bacterial infection will kill the beneficial bacteria in the hindgut, as well as the ones causing the problem. Reducing the hindgut microbial population can lead to laminitis. A potent probiotic is necessary during antibiotic use. In addition, laminitis can be caused by a blood infection resulting from a retained placenta after foaling.
Stress and pain. Any type of stress, whether physical or mental, stimulates the release of cortisol (stress hormone). When cortisol rises, insulin rises, leading to laminitis.
Selenium or iron overload. Pay attention to the total amount of selenium in your horse’s diet. It has a narrow range of safety. And avoid supplementing iron – forage (hay and/or pasture) provides more than enough.
Toxic plants. Purchase a field guide with photos of toxic plants, and walk your pasture to determine any trouble areas.
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