Malassezia Dermatitis(Yeast
infection of the skin) 
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The information contained in this article is for informational purposes only and is not meant to be a substitute
for the advice provided by your own veterinarian. You should not use the information contained herein for diagnosing the health
of a Westie - you should always consult your own veterinarian.
Over the last several years, an alarming number of Westie owners have
been seeking assistance for their Westies that are suffering from the troublesome condition of Malassezia dermatitis.
Despite countless visits to
their veterinarian and an assortment of medications, their Westie’s condition just gets worse and worse. As a result,
the owner becomes more and more frustrated and, all too often, the Westie ends up being abandoned at the vet’s office,
relinquished to a shelter or rescue group, or euthanized.
Most often, the inquiry is a desperate plea similar to the following:
"I own a Westie with severe skin allergies. We have been to the vet on numerous occasions and tried all sorts of medications,
but nothing is working. My Westie is constantly itching and losing its hair. I feel so bad for him/her. Do you have any suggestions
for what I can do to help him/her?"
Does this sound familiar? Is your Westie suffering from itching, hair loss, black oily
skin and/or crusty skin, a musty/yeasty odor, and usually accompanied by an ear infection?
If your response is "yes," than it is quite
possible that your Westie has Malassezia.
Yeast infections are especially itchy, crusty, and smelly. Often the
Westie starts with a rash or a simple itching, and the skin may begin to thicken to an "elephant-like" skin appearance.
The itch gets extreme, and the odor can become especially troublesome.
What is Malassezia?
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Malassezia is the name of a type of yeast (fungus) that is found on both normal and abnormal canine skin
and ears. On normal healthy skin, it causes no problems. To get a yeast infection, conditions on the skin surface have to
change to favor the proliferation of the yeasts. Some conditions which could lead to a yeast proliferation include: high environmental
humidity, an increase in skin oils (from an allergic flare up), an immune deficiency, flea and/or food allergies, or seborrhea
(excessive oil production of the skin). Some Westies are actually allergic to the yeasts themselves.
There are
a number of breeds predisposed genetically to yeast infections; unfortunately, the West Highland White Terrier is one of them.
How is
a Malassezia infection diagnosed?
The most common way to
diagnose Malassezia is with a positive identification of the organism under the microscope. Your veterinarian can
take a microscope slide and press it onto the affected area, then the sticky, oily stuff that clings to the slide can be stained
and examined for the organism. Other methods your vet may use include collecting the material with a cotton swab or scraping
the skin and applying it to the slide. However, because Malassezia is a common resident of normal skin of dogs and
cats, there may always be some doubt as to if it is the causative agent of the symptoms. Therefore, diagnosis is usually confirmed
by response to treatment. (Please note: A Staph infection can have very similar symptoms as Malassezia...loss of hair,
bad odor, etc. When your veterinarian takes the slide, if the yeast organism is found, it could be Malassezia; if a bacteria
organism is found, it could be Staph. Treatment of Staph is very similar. Always consult with your veterinarian.)
It is important to note that
before a primary diagnosis of Malassezia is rendered, other conditions should be ruled out. Allergies to contacted
surfaces, reactions to medications, skin infections (like mange), and atopy (food allergy) may cause similar symptoms. The
goal is to determine if Malassezia is the primary problem or is occurring secondary to another condition. In either
case, the yeast infection must be cleared up.
It is also important to note that yeast infections are not contagious; however, they
can recur if the underlying allergy, seborrhea, etc., is not controlled.
How are Malassezia infections
treated?
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Treatment can be oral, topical, or both. Topical treatment
alone is not usually adequate, but since oral medications are expensive, often topical management alone is attempted first,
especially if only a small body area is involved. (For localized treatment of very small areas, miconazole cream can be applied
twice daily for several weeks.)
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To provide an inhospitable environment for Malassezia, lipids on the skin need to be removed. There
are specifically anti-yeast shampoos that we prefer, such as Malaseb (available from your vet or via mail order - the least
expensive we’ve found is Valley Vet Supply at www.valleyvet.com), Nizoral (easily obtainable over-the-counter at any drug store and works well), and Micro-Tek Medicated Shampoo
(a combination anti-bacterial, anti-fungal, and anti-microbial product also available through www.valleyvet.com).
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The Westie must be bathed twice a week to start for several
weeks. The shampoo should remain lathered on the skin for 10-15 minutes before rinsing. Occasionally, the Westie may become
pruritic after topical treatment. This is not a reaction to the shampoo, but more likely it reflects the release of the toxin
zymogen from the yeast cell wall as the organisms die. This reaction will resolve as the infection is eliminated.
As the condition improves, the Westie should be bathed once a week for several more weeks or until the skin is clear. Leave
on conditioners such as ResiCort and ResiChlor (available from your vet or via mail order - the least expensive we’ve
found is at www.upco.com) have also proven to be of some benefit in some cases. .
For dogs with more severe
cases, or those cases which are resistant to topical treatment, oral ketoconazole (brand name: Nizoral) can be administered
for several weeks (in addition to the baths). A response is generally seen within 1-2 weeks, but therapy needs to continue
for an additional 3-6 weeks. Ketoconozale is very effective, but because of its potentially toxic side effects and expense,
it should only be used under direct veterinary supervision.
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Please note: Malassazia responds poorly to prednisone, and it
should not be used as the main treatment. However, depending on the severity of any internal swelling the Westie may be experiencing,
a cortisone shot and/or a short course of prednisone may be helpful in getting the Westie on the right road to recovery.
NOTE: Our Westie Angel developed this condition in
August 2008. We did not have a clue what it was. We continued to take her to our regular vet who told us it was just an allergy
and that Westies were prone to skin infections. Well nearly 9 Months and several thousand dollars later she still had the
condition and it was getting worse. Underneath her belly was entirely black and her paws were totally raw. At this point we
decided to take her to another vet. The first thing they did was a scotch tape test. They placed a piece of scotch tape on
the infected area and gently pulled it off. They then put the tape under a microscope and within 15 minutes they to us it
was Malassezia Dermatitis (Yeast infection of the skin). They immediately
placed her on antibiotics and within three days she had nearly stopped itching. Within two weeks her hair started growning
back. it has now been three months and she has all her hair back and is not itching anymore. MORAL TO THIS STORY......if we
are not feeling well and our doctor can not give us answers we go to another doctor. Well the same is for our pets if our
vet can not give us the answers and out pet is getting worse take them to another vet and get another opinion.