Digital dermatitis

A histopathological evaluation and some new aspects in the pathogenesis of a multifactorial disease

Abstract

Tissue samples of skin affected by digital dermatitis were studied histopathologically together with post-mortem findings and anamnestic datas to achieve better understanding of this disease. There are hyperplastic, ulcerative, proliferative and combined forms distinguishable. The epidermal cells show signs of degeneration, hypertrophy and hyperplasia, combined with differing extensions of cell destruction by bacteria and spirochetes. Dermal reactions contain arteriosclerosis-like plaques, activation of endothelial cells, thrombosis and different patterns of perivascular infiltration. It is concluded that epidermal lesions are a sequel of dermal malperfusion. Partial or total ischaemia leads to hyperplasia and ulceration, respectively. Endotoxins of gram negative bacteria taking part in other diseases in the same cattle are strongly presumed as causing agents. This indicates a multifactorial pathogenesis.