The tubular portion of the outer ear that carries sound to the eardrum is called the ear canal. Inflammation of the layer of cells that line the external ear canal, called otitis externa, can be short- or longterm and may develop anywhere from the eardrum to the outer ear. Signs of inflammation include redness of the skin, swelling, itchiness, head shaking, increased discharge, and scaly skin. The ear canal may be painful or itchy depending on the cause or duration of the condition. While it is the most common disease of the ear canal in dogs and cats, it is uncommon in horses (see Ear Disorders of Dogs: Otitis Externa in Dogs).

Last full review/revision July 2011 by T. Mark Neer, DVM, DACVIM; Michele R. Rosenbaum, VMD, DACVD; Patricia D. White, DVM, MS, DACVD