Handheld tympanometer measurements in conscious dogs for the evaluation of the middle ear and auditory tube

BACKGROUND: Otitis externa is frequently accompanied by otitis media, yet it can be difficult to evaluate the tympanum, middle ear and auditory tube without the use of advanced radiographic imaging. HYPOTHESIS/OBJECTIVES: The objective was to develop techniques for tympanometry testing in conscious dogs and to present normative data for clinical use of this equipment to enable assessment of the tympanum, middle ear and auditory tube. ANIMALS: Sixteen hounds (14 female) from a school teaching colony. METHODS: Dogs were gently restrained in a standing position. After cleaning of the ear canal, a tympanometer probe tip extension was placed in the vertical canal and automated testing performed using a handheld device. Both ears were tested in all dogs. RESULTS: Acceptable recordings were obtained from both ears of 13 dogs, from one ear in each of two dogs and from neither ear of one dog, resulting in data from 28 of 32 (88%) ears. Otoscopic examination confirmed the absence of inflammation or any other obvious explanation for the noncompliant dogs. No significant differences were seen between ears for any measure. Normative data are reported for peak compliance, peak compliance pressure, gradient and ear canal volume. CONCLUSIONS AND CLINICAL IMPORTANCE: Tympanograms can be recorded in conscious dogs to assist in the evaluation of the middle ear structures