PET HEALTH BULLETIN
Spring 2013
Ear infections
Ear infection is common, and most of
our pets suffer from this painful
condition at some point in their lives.
Scratching of their ear(s), shaking of
their head are mild signs. In trying to
alleviate the discomfort, they might be
seen wiping their ears on the floor or
on furniture. The trauma induced will
lead to reddening of the ear flap or
formation of crust on the inside of the
flap. Occasionally, you might also
notice an abnormal odour or a brown
or yellow discharge. It might be painful
to touch and in serious cases a head
tilts might result.
Causes/Predisposition
Ear infections are caused by a variety
of organisms. Otodectes cynotis, an
ear mite is common in young puppies
or kittens. They feed on the cerum on
the lining of the ear canal causing
irritation of the ear lining. Yeast and
bacterial infections are also very
common. These organisms thrive with
moisture and darkness. Because their
ear canal plunges downwards and
then horizontally from the ear opening,
any caught debris or water has to work
its way up to be released. This makes
it hard to be released. Trapped water
or debris associated with frequent
swimming, bathing or incorrect
cleaning will encourage yeast and
bacteria to grow. Breeds such as
Poodles, Maltese and Shitzus have
abundant hair growth within their ear
canal which reduces ventilation and
encourage infection. Breeds with long
floppy ears, such as basset
hounds and Labradors are
prone to ear disease as they
reduce ventilation of the ears.
Foreign body such as grass
seeds are not uncommon,
especially in spring and
summer.
If an ear infection is recurrent,
there might be an underlying
allergy or metabolic problem.
Food and environmental
allergy cause the skin on the
body to undergo inflammation
leading to itchy skin. Since the
lining of the ear canal is
similar to skin on the rest of
the body, it also undergoes
inflammation. This results in
thickening of the lining in an
already narrow space. Not
only does it feel itchy in the
ear, the space in the inflamed
ear canal restricts proper
ventilation and encourages
darkness which is the perfect
condition for yeast and
bacterial. In worse cases, the
ear canal might become
completely occluded. Growth
such as polyp in the ear could
also lead to a non resolving
ear infection.
Treatment /Diagnosis
When you take your pet to us,
we will first attempt to identify
the organism that is causing
the ear infection. A swab will
be taken from both ears and
placed on a slide for
examination under a
microscope. This allows us to
asses the extent of the ear infection
and picks an appropriate ear ointment
to treat your pets ear(s). Most ointment
from the veterinary clinic contains an
anti-fungal, anti-bacterial and also a
corticosteroid component to reduce
swelling. In severe cases, we might
send the swab for a culture with the
lab. This would tell us specifically
which bacteria is responsible and also
the appropriate anti-biotic for the
infection. In such cases we might start
your dog on oral antibiotics as well as
the ointment. If your dog tolerates
having a sample taken, we will then
perform an otoscopic examination. A
scope is passed down into the ear
canal to look for foreign body or to
assess the extent of the ear infection.
We might also have a look at the rest
of the skin of your dog to determine if
the ear infection might be due to
underlying allergy.
If the ears do not improve with an ear
ointment, we will admit your dog to
have an ear clean. This is usually done
under general anaesthesia. A ear
cleanser is placed in both ears to bring
all the debris up to the surface where it
can be cleaned. Cleanser also
changes the PH in the ear which
inhibits yeast growth. A clear lining of
inside of the ear canal allows better
contact with the ear ointment and
makes it more effective. A clean ear
canal also allows better ventilation.
Dogs with hairy ears will also have
their ears plucked.
Conclusion
Ear infections are uncomfortable.
Cleaning your dogs ears after a swim
or by placing cotton balls in their ears
when you bath them are two
simple ways you can avoid an
infection. In some dogs with
recurrent ear infection, we
need to also manage the
underlying reason for the
infection. e.g food allergy.
While we cannot change the
conformation of the ears of
some breeds predisposed to
ear infection, taking them to
us as soon as you notice any
signs of ear infection will allow
us to manage the ears
optimally.