Insidious progressive bone destruction in a dog surgically treated for otitis media: follow-up by clinical examination and computed tomography

Abstract

A 5.5-year-old Beagle was evaluated for abnormal swallowing and a head tilt of a two-weeks duration. Inspection of the throat and external ear canal revealed an intact but abnormally bulging eardrum. Computed tomographic (CT) examination showed a right-sided tympanic bulla filled with soft-tissue density material, a partially lytic ventral wall and lysis of the petrosal part of the temporal bone. Through ventral bulla osteotomy, sterile cholesterol granuloma and cholesteatoma were diagnosed. The dog recovered but the head tilt re-appeared eight months after surgery. A new CT scan showed expanded lysis of the tympanic wall and increased bone lysis within the petrosal portion of the temporal bone. The owner elected for no further treatment. Another two years later, a third CT scan was performed. Prominent intracranial involvement was present. In contrast to the extent and the progression of the changes, the dog was clinically stable.