Eleanor Kellon, VMD, says cold-induced hoof pain strikes horses with insulin resistance (IR). IR is a well described risk factor for laminitis. Even when a horse is not glaringly lame it is causing damage to the laminae. We haven’t uncovered all the mechanisms behind laminar damage from high insulin levels but one known factor is elevated levels of endothelin-1.
Source: Horse Network, December 26, 2017.
Laminitis caused by high insulin is different from laminitis due to other causes. Activation of enzymes and inflammatory reactions are not part of the picture. This probably explains why the usual treatment with NSAIDs [nonsteroidal anti-inflammatory drugs] like phenylbutazone has little effect.