By Dr. Wendy Pearson, PhD (Dr. of veterinary toxicology)

Laminitis and insulin-resistance (IR) are troublesome conditions in and of themselves, so it is all the more frustrating that they tend to travel together. So while fresh, rich springtime grass beckons winter-weary horses, the insulin-resistant ones must stand resigned and glum on the wrong side of the fence as their well-intentioned owners toss them last year’s browning hay. 

IR can occur in horses just as easily as in humans, and in many cases for the same reasons. The IR horse is typically rather round, has enjoyed too much sugar and starch in his/her diet, is a bit of a couch potato and may have some mineral imbalances. These predisposing characteristics help the cells of the horses’ body to become resistant to the presence of insulin. This causes the pancreas to produce excessive amounts of insulin (i.e., turn up the volume on the radio, so to speak) in an effort to get cells to respond to the presence of insulin. The clinical signs of IR include rather odd fatty deposits in various places on the horse’s body, excessive drinking and urination and, of course, laminitis. 

The insulin-resistant horse looks longingly at early spring pasture.

Laminitis is frustratingly robust to the healing hands of time, and it can take many months before the horse returns to his functional livelihood after an episode. To understand why laminitis is so frequently co-morbid with IR, we need only look to the diabetics in our own lives who struggle with poor circulation in their feet, hands and legs. This occurs because insulin-resistant cells are also defective in production and secretion of nitric oxide – a key molecule which regulates dilation of blood vessels. When less nitric oxide is present the blood vessels cannot dilate properly, typically in metabolically active tissues like those in the feet – or the hooves. This creates a breeding ground for fatty deposits in capillaries which cause release of inflammatory compounds which further exacerbate the problem.

The most effective method for preventing IR-dependent episodes of laminitis is to treat the IR. There are a number of herbs which have shown excellent efficacy in treating IR in humans, one of the most well-studied of which is fenugreek (Trigonella foenum-graecum). Enriching your horse’s diet with high-quality fenugreek and herbs which promote peripheral circulation such as ginkgo (Ginkgo biloba) will help to regulate your horse’s blood sugar, increase circulation to those sensitive bones in his hooves, and may let him finally go where the grass truly is greener.

More by Wendy Pearson

Main photo: Canstock/DecHogan