A 5.5-year-old Beagle was evaluated for abnormal swallowing and a head tilt of a two-weeksduration. Inspection of the throat and external ear canal revealed an intact but abnormallybulging eardrum. Computed tomographic (CT) examination showed a right-sided tympanicbulla filled with soft-tissue density material, a partially lytic ventral wall and lysis of the petrosalpart of the temporal bone. Through ventral bulla osteotomy, sterile cholesterol granuloma andcholesteatoma were diagnosed. The dog recovered but the head tilt re-appeared eight monthsafter surgery. A new CT scan showed expanded lysis of the tympanic wall and increased bone lysiswithin 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 involvementwas present. In contrast to the extent and the progression of the changes, the dog was clinicallystable.