They stand, droop,
or fold. They face forward, backward, or both. “They” are ears. In dogs
the hanging ear is genetically dominant over the upright so a lab/shepherd
cross should always have floppy ears and ears of a chow/shepherd should
always stand. In some dogs the left ear and right don’t even match.
In cats the ears of different breeds vary mainly in size and placement
on the head except for the Scottish fold whose ears bend forward and
the American curl whose ears fold backwards.
The ear flap,
which is call a pinna, is susceptible to injury, which has led to
the practice of cutting or cropping part of the ear, especially in
dog breeds which were once used for fighting or protection. Today
many people believe this practice should be outlawed as it may be
both painful and dangerous for the pet. The tip of the pinna on upright
eared dogs or the fold on ears which flop are often attacked by flies
in the summer . There are a number of sprays and creams which can
be used to repel flies. On white cats the tips of the ears may be
the site of sun induced cancer and they should be monitored if the
cat is outside all the time. Another sort of injury which can occur
to the pinna is a hematoma. It is not certain whether this is a broken
blood vessel or fractured cartilage, but it causes a painful swollen
ear flap which may need to be treated surgically.
The ear canal
of the dog and cat is a long funnel shaped tube which has a right
angle in the middle so that the first part of the canal runs downhill
parallel to the head and then the lower part angles inward to the
ear drum. This unfortunately causes wax and dirt to stay deep in canal
especially when the exterior opening is closed by a hanging ear flap.
Therefore ear infections are common in dogs. Any kind of moisture
in the ear can cause infection, but the most common factor contributing
to ear infection is skin allergies caused by reaction to fleas, food,
or inhalants. The lining of the canal becomes swollen and oozes excess
serum and wax, a perfect medium for the growth of bacteria and yeast.
If the affected ears are not kept clean and dry and free of infection
there can be permanent changes in the cartilage and lining which can
only be corrected surgically. In some cases the only way to free the
dog of pain and infection is to completely remove the entire ear canal.
cause of ear infection is the earmite, a tiny bug about the size of
the dot at the end of this sentence. Mites can cause severe itching
and inflammation or they may be present with no reaction at all. They
can infect cats, dogs, rabbits, and ferrets, but not people, and they
are very contagious. Since infection can be inapparent, when mites
are diagnosed all “in contact” animals must be treated to eliminate
the infection. In rare instances, mites can be present on the head
and body as well as in the ears, and another kind of mite, called
demodex, can infect the ear. There are several different medications
which may be used to kill the mites, and anti-bacterial and anti-inflammatory
medications may also be needed. A veterinarian should be consulted
to confirm the diagnosis and provide the most appropriate medication.
The ear canal
can also be the site of tumors or inflammatory polyps. These may be
seen as a mass in the canal, or bleeding from the canal, or just as
intractable infection when the growth is deep within the canal where
it cannot be seen. In cats, polyps may also grow down the eustachian
tube into the throat where they can interfere with breathing. Polyps
are often due to long standing inflammation or infection and may become
tumors if the cause is not eliminated. But the growth must be removed
to treat the cause.
The inner ear
is the center of balance, and inflammation or infection of the inner
ear can cause loss of balance or head tilt. Ear infection may extend
from the outer ear canal, or there may be no evidence of infection
in the visible ear canal if the infection enters the middle ear through
the eustachian tube from the throat or by way of the blood stream.
Middle and inner
ear infections may respond to oral antibiotics or surgical treatment
may be necessary to drain the fluid and pus from the bulla which is
the echo chamber attached to the inner ear. Special x-rays taken under
anesthesia may be necessary to diagnose the condition and determine
if surgery is indicated. There are many cases of vestibular syndrome
in the older dog or cat which have no infection present and which
improve with time. The loss of balance may be so severe that the affected
animal is unable to stand at all and simply rolls on the floor.