Impedance audiometric measurements in clinically normal dogs

Objective-To measure impedance audiometric values in clinically normal dogs that were sedated or anesthetized, evaluate effects of ear flushing on tym panometric measurements, and determine effects of performing acoustic refle x testing in a sound-attenuated room. Animals-35 mixed-breed and purebred client-owned dogs and 21 laboratory-bre d Beagles. Procedures-Tympanometry and acoustic reflex testing were performed on 27 mi xed-breed and purebred dogs under isoflurane anesthesia in a non-sound-atte nuated room and 21 Beagles under sedation in a sound-attenuated room. Tympa nometry was per formed on 8 mixed-breed dogs under halothane anesthesia bef ore and after ear canal flushing. Results-Among impedance audiometric values, ear canal volume and compliance peak were smaller in Beagles than in mixed-breed dogs; differences among o ther values were not detected. Ear canal volume was dependent on body weigh t. Differences were not found for tympanometric values measured before and after ear canal flushing. Conclusions and Clinical Relevance-Results of this study established refere nce range values for impedance audiometric measurements in clinically norma l dogs under isoflurane anesthesia or sedation. Acoustic reflex testing doe s not need to be performed in a sound-attenuated room. The ear canals of cl inically normal dogs can be flushed prior to performing tympanometry withou t altering the results. Impedance audiometry may be a useful noninvasive pr ocedure for the diagnosis of otitis media in dogs.