Ear Infections
Ear infections in our pets can come from many different organisms. Some of these organisms are
bacterial in origin and some are fungal. Chronic ear infections in our pets however often stem from
the same source, allergies. Diseases of the ear often stem from excess heat and wax production
due to irritation brought on by allergies. The increase of heat and moisture becomes a little
incubator allowing these organisms to produce in abundance.
As shown in the picture above the dog’s ear canal is also a perfect set up for these organisms to
grow with both a vertical and horizontal component, which is much longer, and less accessible than
our ear canals.
Dogs will often show discomfort in their ears by a variety of behaviors. These include shaking of the
head, rubbing of the ears, scratching at ears and neck, and if the infection has progressed to the
middle ear even lack of balance and a tilting of the head.
To diagnose the culprit of a particular dog’s ear problems and ear cytology is often performed. This
is where a swab of the ears is taken and the debris from the ear is placed on a microscope slide.
Under the microscope bacteria, yeast, and ear mites can all become evident. The following
paragraphs will breakdown the different organisms and the preferred treatment involved in each.
Yeast Infections
Yeast is the most common cause of ear infections in dogs. Yeast is a fungus that really enjoys
warm, dark, and moist conditions in the ear canal. Just like on our own skin there is a small
amount of yeast within the ear but when conditions are right they tend to over grow irritating the ear
and producing a brown sour smelling discharge. Treatment often begins with a professional
cleaning of the ears, followed by a regimen of medications at home. These medications are
typically an anti-fungal combined with a topical steroid to reduce the inflammation in the ear.
Occasionally, pain medicines are also giving when the pet seems more uncomfortable than normal.
Bacterial Infections
Bacterial infections can be cause by a whole host of different bacteria with the most troublesome
being a species call pseudomonas. Normally, in a bacterial infection the inflammation is combined
with a sweet smell and a yellow colored discharge. Treatment of bacterial infections can be a little
more involved than a yeast infection. Often after a professional cleaning in the office an ear drop
containing a combination of antibiotics is sent home. (When treating your dog for a bacterial
infection it is important to wear protection in the form of gloves when handling the ear. This
becomes extremely important if you have any open cut or a suppressed immune system) This
medication does a pretty good job on most bacterial infections that affect the ear but not all. If the
infection continues it is often important to do a culture of the ear. A culture consists of taking a
sterile swab and getting a sample of the discharge coming from the ear. This is then placed into a
sterile container and sent to the lab. After letting the bacteria in the discharge grow for a few days
the pathologists at the lab look under the microscope and identify the species of bacteria. They will
also identify what kinds of antibiotics this particular species is susceptible to. This is extremely
important with the pseudomonas species that is resistant to many of the usual medications used.
Pseudomonas is also a species that builds resistance to antibiotics rapidly often making it less
susceptible to a particular antibiotic with each use. When it comes to ear infections it is very
important to complete all treatments if the infection is better but not completely gone at the end
of prescribed treatment please contact your veterinarian it may be necessary to extend
treatment out longer.
With chronic ear infections it is very important to get control of the underlying cause. This is often
an allergy. Both inhaled and food allergies cause chronic ear inflammation and it is important to
speak to your veterinarian about a treatment for these allergies that can reduce inflammation.
Sometimes this is as simple as changing the protein and or carbohydrate that is in your pets
current food. Other times allergy testing or seasonal steroid treatments maybe needed.
When chronic ear infections continue over a long period of your dogs life sometimes an ablation is
needed. This is the final option available in patients that no other treatment has worked causing the
ear canal to become scarred and swollen. An ablation is a surgical procedure where the entire ear
canal is removed and healthy tissue is allowed to fill in. This procedure requires a specialist and
can be very expensive but dogs with severe chronic infections often never require any more
treatment.
Aural Hematomas
When a dog’s with uncomfortable ears shakes and scratches vigorously, a blood vessel in the
earflap may rupture. This leads to bleeding within the pinna or earflap and since it is between the
two sides this blood has nowhere to go often forming a “pocket” in the earflap. This blood clots and
creates a hematoma. The treatment for this condition may vary but typically it becomes a
combination of a surgical procedure and treatment for the existing infection. Simply draining these
clots is not a viable option because the body tends to fill it right back up with fluid. The surgical
procedure consists of making a couple small incisions in one side of the earflap. The clots are then
removed and a drain is sutured into the earflap. Following the placement of the drain the ear is
then bandaged to the top of the head for 24 hours. Once the bandage has been removed the drain
needs to stay in for 10 days with the owners massaging the earflap everyday to remove any fluid
that might build up. In some less severe cases we can forgo surgery however, in these cases we
risk the earflap scarring down and covering the ear canal preventing treatment of future ear
infections.