Hearing in the dog as assessed by auditory brainstem evoked potentials

Area of Science:

• Veterinary Neurology
• Auditory Neuroscience
• Comparative Physiology

Background:

• Assessing canine hearing is crucial for diagnosing deafness and understanding auditory development.
• Auditory brainstem evoked potentials (ABEPs) are a non-invasive electrophysiological method to evaluate auditory pathway function.

Purpose of the Study:

• To establish and validate a technique for measuring auditory brainstem evoked potentials in dogs.
• To determine the ABEP characteristics in normal adult dogs and puppies.
• To assess the utility of ABEPs in identifying deafness in dogs.

Main Methods:

• Auditory brainstem evoked potentials were recorded from conscious or sedated adult dogs, puppies, and deaf dogs.
• Click-evoked auditory stimuli were used to elicit brainstem responses.
• Waveform analysis, including peak latencies and intervals, was performed.
• Hearing thresholds were determined in adult dogs.

Main Results:

• Reproducible ABEPs, typically with four peaks (I-IV) within 5 ms, were obtained in normal adult dogs.
• Brainstem auditory thresholds in adult dogs ranged from 5 to 25 dB normal hearing level.
• ABEPs were absent in 2-week-old puppies but present by 3 weeks.
• Latencies and intervals shortened between 3 and 7 weeks, approaching adult values.
• No ABEPs were detected in four deaf dogs.

Conclusions:

• Auditory brainstem evoked potentials provide a reliable method for assessing hearing in dogs of various ages.
• This technique can differentiate normal hearing from deafness and track auditory maturation in puppies.
• ABEPs are a valuable diagnostic tool in veterinary audiology.