This hereditary defect originated in the Landrace breed. The defect can be expressed as foot deformities present at birth, or later as widely distributed expanding cutaneous lesions that involve small to large areas of skin. Skin lesions usually are apparent by the third week although some develop later. Skin lesions begin as papules and expand to form roughened plaques that soon become papillomatous. Most affected pigs die within six weeks. Many that survive have dyspnea related to interstitial pneumonia of giant cell type.