Brainstem auditory evoked response (BAER) testing is an electro-diagnostic test used to evaluate the hearing of dogs, cats and other domestic animals.
It evaluates the components of the external ear canal, middle/inner ear cavities, cranial nerve and selected areas of the brainstem. It is a non-invasive procedure that takes 5 to 15 minutes to perform. In some circumstances, sedation is used. If the hearing threshold needs to be determined, more often in older patients, general anesthesia is recommended. From small subcutaneous electrodes and externally applied acoustic stimuli of different intensity, we record numerous waves, each of which represents composite neuronal activity.

BAER testing is used for, early diagnosis of hearing loss secondary to cochlear agenesis/degeneration. Assessment of brainstem (caudal part of the brain) function. Conductive hearing loss, which is the result of a dysfunction of the external ear canal and middle ear space. Sensorineural hearing loss, which is the result of dysfunction of the cochlea, cochlear nerve or central auditory pathway. Most responsible breeders of dogs who are high risk for congenital deafness will test parents and/or litters of puppies before selling them.