Some of this sounds similar in some respects to Cushing's Disease. These circulatory blockages Pollittt's corrosions show in the toe raise the horse's blood pressure. Normally, these pathways between the veins and arteries, which shunt blood away from the nutritive capillary bed of the laminae when open, remain closed. They normally only open briefly and repeatedly in situations like the horse standing in snow or icy water, to prevent chilling of the foot. The hope is that if the AVA's paralysis can be better understood, perhaps we can prevent their remaining frozen open during an attack of laminitis by either neuroactive drugs, immunologic or biomolecular approaches.
Research is still ongoing.
He believes this swelling squeezes the blood vessels shut. He draws this conclusion from Dr. Pollitt's microscopic studies of both normal and foundered laminae. The insensitive laminae appear to be bloated with edema and water, thereby compressing the smallest blood vessels in the sensitive laminae. This cuts off circulation. Dr. Frederick's view, implicating hydraulic pressure inside the laminae, is closer to Dr. Strasser's view, but she believes that a lack of hoof mechanism due to incorrect hoof form and inactivity are the real culprits.