Pathology of bovine laminitis especially as regards vascular lesions.

Macro- and microscopical changes in the hooves of 14 cattle having a clinically established diagnosis of laminitis are described, Deviation of the pedal bone was found in 10 of the animals. In acute laminitis, the microscopical changes in the corium were hyperaemia, oedema, thrombosis and haemorrhages. Degenerative changes were found in the epidermis especially in the vicinity of thromboses of vessels in the corium. In chronic laminitis, arteriolosclerosis and arteriosclerosis were constant findings in the corium. There was also a high frequency of chronic thrombi and chronic granulation tissue. Prominent features in the lamellae epidermales were hyper- and parakeratosis. As judged from changes in arterioles and arteries, hypertension is suggested to be a pathogenetic factor in bovine laminitis. cattle; laminitis; histology; arteriolosclerosis; arteriosclerosis.