The histopathological changes in the skin of pigs with dermatosis vegetans.

Dermatosis vegetans, an hereditary disease seen in Landrace swine, is characterized by defects in the skin, and a giant cell pneumonia. Histological changes of the skin from 12 affected pigs of various ages were described. Lesions of the skin were characterized by acanthosis, hyperkeratosis, parakeratosis, and leukocytic infiltration. In general, the defects followed a definite developmental pattern, which were divided into three stages: (1) the stage of early development, (2) the intermediate stage characterized by an acute inflammatory response, and (3) the stage of regression. The specific role of the eosinophil, a prominent feature in this and other diseases of the porcine skin, remains obscure.