This inherited condition occurs in at least four breeds and is characterized by the absence of discrete areas of skin, usually over a part of the back, loin or thigh.
Lesions occasionally occur on the anterior surface of the tongue. Hydroureter and hydronephrosis commonly accompany the condition. Fetuses with extensive lesions may be aborted. Piglets born alive with extensive lesions usually die from bacterial invasion and septicemia. Minor defects may heal.