Audiograms Estimated from Brainstem Tone‐Evoked Potentials in Dogs from 10 Days to 1.5 Months of Age

The objective of this study was to build audiograms from thresholds of brainstem tone‐evoked potentials in dogs and to evaluate age‐related change of the audiogram in puppies. Results were obtained from 9 Beagle puppies 10–47 days of age. Vertex to mastoid brainstem auditory‐evoked potentials in response to 5.1‐millisecond Hanning‐gated sine waves with frequencies octave‐spaced from 0.5 to 32 kHz were recorded. Three dogs were examined at 10, 13, 19, 25, and 45 days. Four other dogs were examined at 16 days. Data from 7 dogs between 42 and 47 days of age were pooled to obtain audiogram reference values in 1.5‐month‐old puppies. The best auditory threshold lowered from above 60 dB sound pressure level (SPL) to values close to 0 dB SPL between 13 and 25 days of age and then stabilized. The audible frequency range widened, including 32 kHz in all tested dogs from the 19th day. In the 7 1.5‐month‐old puppies, the mean auditory threshold decreased by 11 dB per octave from 0.5 to 2 kHz. The auditory threshold was lowest and held the same value from 2 to 8 kHz. The mean auditory threshold increased by 20 dB per octave from 8 to 32 kHz. Near threshold, click‐evoked potentials test only a small part of the audible frequency range in dogs. Use of tone‐evoked potentials may become a powerful tool in investigating dogs with possible partial hearing loss, including during the auditory system maturation period.