Histopathological and morphometric studies on the hooves of dairy and beef cattle in relation to overgrown sole and laminitis.

In dairy cattle, histopathology of the outer hind claws with overgrown sole revealed arteriosclerosis of blood vessels at the ulcer site in the sole. The laminae did not show any hyperplasia of the epidermis and thrombi were not seen in the blood vessels. Partial or complete disappearance of onychogenic substance was observed in the sole as well as in the wall epidermis. In beef animals, typical changes suggestive of chronic laminitis were seen: these included hyperplasia of the epidermis of the laminae, thrombus formation, arteriosclerosis in the corium of the sole, the abaxial wall and the coronary corium. Morphometric analysis quantified measurements of hooves of normal, beef and dairy cattle. It may be concluded that the changes associated with overgrowth of the sole in dairy cattle are localized to the sole without involvement of the laminae and that the term laminitis is not appropriate in the condition seen in dairy cattle.