Deafness and Hearing Loss in Cats
Some cats are born without the
ability to hear because of developmental defects in the hearing apparatus. Cats
may also be deaf in just one ear. Congenital deafness occurs most often in
white cats with blue eyes, and is the result of an incomplete autosomal
dominant gene. However, not all cats with blue eyes are deaf, and that includes
not all white cats with blue eyes. Longhaired cats with blue eyes have a higher
risk of deafness than shorthaired cats with blue eyes. White cats with the
Siamese dilution gene may have blue eyes with no hearing impairment. Still,
white cats have a higher risk of deafness than other cats in general, and
blue-eyed cats also have a higher risk of deafness-even if they have only one
blue eye. Congenitally deaf cats should not be bred.
Common Breeds with the White Coat Pigment Gene
Norwegian Forest Cat
Maine Coon Cat
Gradual Hearing Loss
Loss of hearing can be caused by old age, middle ear infections, head
injury, blockage of the ear canal by wax and debris, and by certain drugs and
poisons. In particular, the antibiotics streptomycin,
gentamicin, neomycin, and kanamycin, if used for long periods, can damage the
auditory nerves, leading to deafness and signs of labyrinthitis.
Gradual loss of hearing occurs in some older cats. Elderly deaf cats,
however, often retain their ability to hear high-pitched sounds beyond the
range of human hearing.
It is difficult to tell if a cat is going deaf. The ability to hear must be
judged by observing the cat’s actions and how she uses her ears. Cats who hear
well cock their heads and look toward a sound. The ears swivel to pinpoint the
source of the sound. Accordingly, lack of attentiveness is one of the first
indications that a cat is not hearing well. One way to test this is to make a
loud noise while the cat is asleep. If the cat does not startle and wake up,
you can assume there is a significant loss of hearing. Suddenly touching a
sleeping deaf cat without a warning could result in a scratch or a bite as the
cat is startled when she wakes up. Stamping on the floor will attract a deaf
cat’s attention, because she can feel the vibrations.
Deaf cats get along quite well. They use their senses of sight and smell and
the tactile sensations transmitted through their whiskers to compensate for the
hearing loss. However, deaf cats should not be allowed outside.