Dog Owner's Home Veterinary Handbook.pdf - Mr. Walnuts

218 •DOG OWNER’S HOME VETERINARY HANDBOOK
sensitive structures of the inner ear. This is why the ears should never be flushed
or medicated without first making sure that the eardrums are intact.
Other causes of labyrinthitis include head trauma, brain tumor, poisoning,
and drug intoxication. Suspect one of these if your dog develops labyrinthitis
without having had a prior ear infection.
Treatment: The underlying cause must be diagnosed and treated.
Supportive care and medications to relieve the symptoms assist in recovery.
Deafness
This Boston Terrier shows
the typical posture of a
dog with labyrinthitis. The
head is tilted down on the
affected side.
For a dog to hear, the cells that transmit sounds must be intact, as must the
brain cells that interpret the sounds. Hearing loss can be caused by congenital
deafness, changes of old age, middle and inner ear infections, head injuries,
wax and debris blocking the ear canals, tumors of the middle ear, and certain
drugs and poisons. The antibiotics streptomycin, gentamicin, neomycin, and
kanamycin can damage the auditory and vestibular nerves, causing both deafness
and labyrinthitis. Hypothyroidism can be associated with a type of deafness
that may respond to treatment with thyroid hormone.
Congenital deafness is caused by developmental defects in the hearing
apparatus. Although present from birth, it is not evident until puppies are old