Rational clinical management of canine AD is required, since AD is usually a life-long disease that can be controlled but rarely cured. The age of onset of canine AD is typically between 6 months and 3 years and the most important clinical features include the presence of pruritus, associated with skin lesions of a characteristic distribution around the mouth, eyes (especially in the presence of conjunctivitis), ears, flexor aspects of elbow, carpal and tarsal joints, digits and interdigital skin, ventral abdomen, perineum and ventral aspect of the proximal tail