NORMATIVE AUDITORY BRAIN-STEM RESPONSE DATA FOR HEARING THRESHOLD ANDNEUROOTOLOGICAL DIAGNOSIS IN THE DOG

There is growing interest in the application of auditory brainstem res ponse (ABR) audiometry for hearing assessment in dogs, The technique i s far from standardised, however, resulting in large discrepancies bet ween studies, This study aimed to obtain normative data, under clearly defined conditions, for two breeds of significantly different size; h ead size being a potential factor determining ABR latency values, The subjects, 20 dalmatians and 20 Jack Russell terriers, were sedated pri or to ABR testing, and subcutaneous scalp electrodes used to detect th e evoked potential elicited by a click stimulus presented via insert e arphones, The mean ABR thresholds for the two breeds, 0 and -5 decibel s re normal hearing level (dB nHL), respectively, were very similar to those for humans, The latency values of the main ABR waves and the in terval between them were statistically significantly smaller for the s maller breed, but there was no correlation with head size within eithe r breed. The results provide a baseline to assist with confirmation of hearing impairment and neuro-otological diagnosis in the dog.