EFFECTS OF OTITIS ON HEARING IN DOGS CHARACTERIZED BY BRAIN-STEM AUDITORY-EVOKED RESPONSE TESTING

Hearing function was measured in normal dogs and in dogs with otitis u sing brainstem auditory evoked response testing. Data were obtained fr om 86 normal ears and from 105 ears with otitis, categorised into four degrees of severity. The data were analysed to illustrate the differe nces between the hearing function in the normal and abnormal ears and to estimate the degree of impairment associated with differing degrees of pathology. While severe hearing loss seemed to be present in the d ogs with more severe otitis, only two individuals were identified as b eing totally deaf in the affected ears and no dogs were identified in which the cleaning and examination processes had caused damage to hear ing function. Cleaning the ear canal produced measurable improvements in hearing in several dogs, indicating the profound effect of physical obstruction of the external ear canal by debris. It is concluded that most dogs with chronic otitis externa are not totally deaf and that t he hearing impairment that does occur has the characteristics of condu ctive hearing loss.