Use of BAER to identify loss of auditory function in older horses.

Abstract

OBJECTIVE: To use the brainstem auditory evoked response (BAER) to test the hypothesis that auditory function could be worse in older horses than in younger horses. PROCEDURE: BAER waveforms in response to click stimuli were measured in five younger horses (5-8 years) and four older horses (17-22 years). RESULTS: Compared with the younger horses, the older horses showed significantly (P < 0.02) worse BAER thresholds and significantly (P < 0.02) worse BAER wave V amplitudes to the 90 decibels above normal hearing level stimulus. These results were consistent with partial deafness in the older horse group. CONCLUSION: BAER assessment can be used to identify partial deafness in older horses. Such horses should be managed appropriately, with particular care taken in noisy environments where hearing loss could put the horse and/or its owner at risk of harm.