Anwer Cona, Schwarz Tobias, Volk Susan W, Vite Charles
Department of Clinical Studies, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA, USA.
J Am Anim Hosp Assoc. 2011 Sep-Oct;47(5):370-4. doi: 10.5326/JAAHA-MS-5545. Epub 2011 Aug 18.
A 3 yr old male castrated Labrador retriever presented for evaluation and treatment of bilateral atresia of the external ear canals. The owners reported that the dog could hear only loud and high-pitched noises. Computed tomography of the head revealed intact vertical and horizontal ear canals filled with debris and a debris-filled right tympanic bulla. Air- and bone-conducted brainstem auditory evoked response (BAER) testing revealed an elevated response threshold to air-conducted stimuli and greater amplitude waveforms evoked by bone-conducted stimuli. The ear canals were surgically corrected via lateral ear canal resection. BAER testing postoperatively revealed a decrease in the air-conducted BAER threshold. This case is an example of the use of bone-conducted BAER testing to aid in the diagnosis of conductive deafness, and in determining prognosis for normal hearing after surgical treatment of external ear canal atresia.
