This is a skin disease caused by a buildup of skin oil (sebum) on the hair along the edges of the ear flaps. The hair has a greasy feel. When rubbed with a thumbnail, the hair falls out. The disease is most common in Dachshunds.
Treatment: Marginal seborrhea is incurable, but it can be controlled by bathing the ears with benzoyl peroxide or a sulfur-tar shampoo (see Seborrhea). Soak the ear margins in warm water (using compresses) before shampooing. Put cotton balls in the ear canal to prevent any water from dripping down into the ear. Repeat every 24 to 48 hours until all the greasy material has been removed. Use a moisturizer to keep the ears soft and pliant. Repeat the treatment as necessary. If the skin is severely inflamed, apply 1-percent hydrocortisone ointment.