Dog Ear Yeast Infection Treatment
Summary:
Yeast infection in dog ear is the most
common type of canine ear problem. Mild conditions can be treated with
home ear cleaners with more severe or infected cases requiring a
veterinarian. The condition often due to another condition, such as a
food allergy reaction, which should be addressed in order to avoid
future problems. In the case of a food allergy reaction, it requires a
change in diet and possibly nutritional supplements. Some
perpetuating factors, such as the natural dog ear anatomy, particularly
in dogs with long pendulous ears, is factor that requires some level of
owner awareness, since problems are always a risk.
Treatment for mild conditions are topical,
often using a combination of glucocorticoids, anti-fungal agents. The
basic principal is to acidify the ear canal, making it undesirable for
the growth of yeast. If bacteria are present as well, a veterinarian
may opt for product that can address both. All treatments starts with a
thorough cleaning of the ears. For more chronic cases, oral
anti-fungal agents along with a glucocorticoid (prednisone) are used."
Overview
Yeast infections (malassezia) are common in dogs who have allergies
and are the most common ear problem seen by veterinarians. Yeast is
also referred to as Malassezia Dermatitis, which is a type of fungal
infection. Dog ears
contain mast cells, just like the mast cells contained in the
respiratory systems of humans. These mast cells produce histamines,
prostaglandins, and other inflammatory chemicals in response to
allergens. These chemicals stimulate the ears to over-produce wax and
other secretions. Skin bacteria thrive in the warm, gooey environment
of these ears. Yeast spores are also attracted to the ears and begin to
germinate.
Magnified View of Cytologic
Preparation of
Dog Yeast Infection Organisms
(Malassezia)
Dogs with floppy ears are much more susceptible to yeast infection
in dog ear than dogs with erect ears, because their ears provide a
warm, dark place for yeast to grow.
Yeast infections (Malassezia otitis) may also be the result of an
adverse food reaction or as a reaction to ear mites. In middle age
dogs, allergy (atopy) or a problem with the endocrine gland
(endocrinopathy) should be considered as well as reactions to food.
Several breeds have a higher propensity of yeast overgrowth:
- West Highland White Terrier
- Poodle
- Dachshund (need to rule out Acanthosis nigricans first, with is a
thickening of the skin).
- English Setter
- Basset Hound
- American cocker spaniel
- Shi Tzu
- Springer Spaniel
- German Shepherd
Symptoms
Symptoms of yeast infection in a dog ear include increased
production of ear wax and other secretions. Ear wax may appear to be
pinkish-brown and often the ear will have a bad smell.
You won't be able to see it without magnification, but your vet will
notice upon examination with a magnifying device that the ear tissue
has changed to become thicker and spongier.
Your dog's ears will itch. He will probably scratch or paw at them.
He may also rub his nose with his paws, another a sign of allergies.
Another sign of allergy is recurring ear infections during certain
times of the year and no problems at other times.
In chronic cases the ears can change color (hyperpigmentation) and a
thickening and hardening of the skin (lichenification) can occur.
Dog Ear With Yeast Infection

Diagnosis
Your veterinarian may suspect a yeast infection based on the amount
and color of the ear wax and other secretions. They will look at the
ear tissue of your dog when examined with a magnifying device. An ear
wax sample will be taken with a swab for examination under a
microscope. The veterinarian will make a diagnosis based on the
excessive number of yeast cells. Response to treatment can also
be used to confirm a diagnosis.
The testing process will allow your veterinarian to rule out other
types of infections. Secretions collected will be cultured for yeast, a
test that takes 10 - 14 days in order for a diagnosis to be made. In
the meantime, your vet will probably go ahead and begin treatment for a
yeast infection.
Several conditions with similar symptoms to a yeast infection in dog
ear problem will need to be ruled out before a definitive diagnosis is
reached. These include:
- Flea allergy
- Food Allergy
- Atopy (environmental or seasonal allergy)
- Superficial bacterial folliculitis
- Seborrhea (both primary and secondary forms)
- Acanthosis nigricans (dachshunds only)
Treatment of Dog Ear Yeast Infections
Yeast infection in dog ear is treated first by cleaning out the ears
with a gentle cleansing solution. When using a ear
cleansing solution or wash, a few drops should be applied
to the
inside of the ear flap and then the tip of the ear wash bottle should
be inserted a few millimeters into the ear canal. Do not tightly force
the tip of the bottle into the ear canal as forceful squeezing of the
bottle with the bottle wedged into the ear canal could rupture the ear
drum.
Most Dogs will shake their head after the wash is inserted into the
ear, shaking out much of the solution. Massaging the wash solution into
the dogs ear. A tip is to massage the base of the ear which distributes
the wash throughout the ear canal.
Ear cleaning will remove any debris that might cause inflammation
such
as yeast. For swelling, a veterinarian may use glucocorticoids for up
to two weeks. This will also eliminate any pain. As an
alternative, a veterinarian may use NSAIDS. About 1/3 of dogs
have an avoidance reaction to ear cleaning, making it easier to perform
in the veterinarian's office.
They are then treated with a topical ointment that usually contains
an antifungal agent and glucocorticoids. Ointments with mineral oil are
thought to keep the ear clean without the need for additional separate
cleanings. Antifungal agents include Nystatin, clotrimazole 1%,
miconazole 1% and ketoconazole .1%. If tests show the presence of
bacteria and Malassezia otitis (fungal infection), there are
combination
products that address both.
In dogs that have a more chronic yeast infection in the dog's ear or
in cases where both bacterial and Malassezia is present, a veterinarian
may recommend an oral medication. Antifungal agents include
Keotconazole (5 to 10 mg/kg sid, given with food to enhance
absorption), itraconazole (5 mg/kg sid) and fluconazole (10 mg/kg sid).
In cases where the ear canal has narrowed (stenosis) or if there is
excessive fluid accumulation (edematous) a dog may be put on a
glucocorticoid (prednisone) for one to two weeks.
To control the inflammation and itching, an antihistamine such as
benadryl may be recommended.
Since yeast infections are often related to allergies, the
allergen(s) must be identified and dealt with. Often it is a food
allergy. Switching your dog to a special diet for allergic dogs may
help. Iams makes a lamb and rice food especially for dogs with allergy
problems. Hills Science Diet has a formula for allergic dogs as well.
Treating a yeast infection can take up to three weeks, and if
allergies are the main cause and if they are not dealt with, the
infection usually returns.
The veterinarian will follow-up in 2 to 4 weeks after treatment begins
to monitor progress. Symptoms such as any bad odors or itch will
improve within 1 week. If the problem frequently occurs, a
veterinarian will need to determine the underlying cause.
Home Remedies
Home use of an acetic acid/boric acid solution such as Dermapet
Malacetic Otic can be effective in treating yeast infection.
The
ear cleaner or flush is used daily for 7-10 days by filling the ear
canal to overflowing, massaging the base of the ear, and allowing the
solution to remain in the ear canal for 5 minutes. Loosened debris is
wiped off of the concave pinnal surface with a dry cotton ball. This
procedure is repeated once daily. When the ear canal is clean, the
cotton ball will remain fairly white when the solution is wiped away.
At that time, home ear cleaning is reduced to once weekly.
If the problem happens often, you might want to consider a dietary
supplement designed for ear conditions. Dog ears contain wax and a
variety of flora (e.g. yeast and certain bacteria). This can be healthy
and helps to keep ears clean and free of infection. Herbal products
help to maintain the natural balance of flora and healthy organisms in
the ear. A solution worth trying are ear drops made by Pet
Alive Ear Dr. which contains a blend of herbs selected for
ear
health.
Brochure and References:
Brochure on dog ear yeast infection:
For additional reading on Yeast
Infection in Dog Ear Problems:
Examining and Medicating the Ears of a Dog
Washington State University
College of Veterinary Medicine
Diseases of the Outer Ear
Haar, G. Ter DVM
Brevitz, Betsy
Hound Health Handbook
Malassezia Otitis Externa - Etiology and Treatment
L.N. Gotthelf
Animal Hospital of Montgomery, Montgomery, AL, USA.