Dogs and cats normally have better hearing than we do. Even so, just like people, pets can lose some or all of their hearing because of age or damage to the nerves and other structures within the ear. Hearing loss is also genetically linked in certain breeds, including the Australian Shepherd, Boston Terrier, Cocker Spaniel, Dalmatian, German Shepherd, Jack Russell Terrier, Maltese, toy or miniature Poodle, and West Highland White Terrier.

The ear is divided into outer, middle, and inner portions. Sound waves vibrate the ear drum between the outer and middle ear. Bones in the middle ear transfer this vibration into nerve impulses within the inner ear. Damage to any portion of this system can lead to hearing loss. Some nerve damage is expected with age, so some degree of hearing loss is typical in older pets.

Other causes of hearing loss include repeated ear infections of the outer ear that can narrow the ear canal, infections that go beyond the outer ear and affect the middle or inner ear, and certain drugs in some situations.

Hearing loss is not always easy to notice, because pets use their other senses to adapt. For example, responses to noises like clapping hands or slamming doors are not usually good indicators of hearing, because deaf pets may still feel the vibration. Dogs and cats also use their highly developed sense of smell to locate people and things.

Better tests of hearing involve noises that are not associated with much movement or vibration, such as the sound of a doorknob jiggling outside the sight of your pet. Deaf pets may not respond when you call or approach them from behind, and they may be startled when they realize that someone is there.

Your veterinarian will examine your pet's ears for obvious problems, such as an infection a buildup of wax or hair. If one of these problems is causing the hearing loss, some hearing may return after treatment. Fortunately, in cases of permanent hearing loss, most pets adapt readily and continue to enjoy their day-to-day life.