Download Don`t Overlook Yeast when the Skin Itches

Don’t Overlook Yeast when the Skin Itches
By Dr. Ed Mapes
Have a pet with itchy, smelly skin that is thickened and dark-colored? Could be a yeast
infection? Yeast is one-celled microorganisms that inhabit the skin of normal animals
without causing symptoms of disease. The animal’s immune system normally inhibits
the organisms to small numbers that cause little problem. Malassezia pachydermtis is a
yeast that inhabits the skin and ear canals, and causes real trouble when the immune
system loses control.
Figure 1: Malassezia pachydermatis yeast
Figure 1 Malassezia pachydermatis yeast look like footprints on this microscopic view.
Some of the cells are seen to be “budding”, which is how they divide to reproduce.
Dogs are affected most commonly, but cats can get yeast infections too. These breeds
are genetically predisposed to yeast infections: the West Highland White Terrier, Basset
hound, Cocker spaniel, Silky terrier, Golden Retriever, Australian terrier, Maltese,
Chihuahua, Poodle, Shetland sheepdog, Lhasa apso, and the Dachshund. However,
because of the skin folds normally present, Bulldogs and Shar Pei dogs the most
frequent victims.
So what conditions lead to a yeast proliferation? Yeast thrive in moist areas of skin. Any
dog or cat with skin folds is a likely candidate; Bulldogs with wrinkles all over –
especially on the face and tail area – are prime examples. Spaniel breeds are at risk for
a condition called “lip fold pyoderma” since they often have folds of skin on the bottom
lips that accumulate moist debris and serve as a breeding ground for yeast and
bacterial infections.
Seborrhea oleosa is condition in which the animal produces excessive oils on the skin.
This is especially bad when skin folds are present also. Cocker Spaniels are well
represented in this category. Animals with allergic dermatitis often have secondary
yeast infections, which arise due to the inflamed condition of the skin. Some animals are
actually allergic to the yeasts themselves An immune deficiency or hormone imbalance
can also promote yeast proliferation. The most important thing to realize is that while a
yeast infection is not contagious, it tends to recur unless the underlying allergy,
seborrhea, skin fold, or other problem is controlled.







Some other factors leading to yeast infections include:
The prior use of antibiotics that wipe out beneficial bacteria that help to control yeast.
Weakened immune system from a variety of causes like chronic disease, corticosteroid
or other immuneosuppressive drugs.
Stress, which compromises the immune system.
Imbalanced diet – Poor in protein and fibers, rich in carbs.
Thyroid disorder that causes hormonal and metabolic imbalances.
Cushing’s syndrome that elevates cortisol levels and weakens immune response.
Whelping and lactation
We diagnose yeast infections by a number of methods; most are ways to get organisms
from the skin or ears onto a microscope slide for staining and observation. We can get a
good clue though because of the severe itch and characteristic smell of yeasty skin.
Chronic infections are also easy to diagnose; the skin turns dark and becomes
thickened (lichenified). Figure 1 illustrates a chronic yeast infection and the skin
changes it causes.
Figure 2: Chronic Malassezia infected skin
Figure 2 chronic Malassezia infected skin can become pigmented (darkened) and
thickened to resemble elephant skin. It can really smell bad too, and itches terribly.
Treatment of yeast infections can include systemic medication with one of the
“conizoles” like ketoconizole or fluconazole. Since bacteria often co-infect the skin,
antibiotics are often prescribed as well. Ear drops along with ear cleaning solutions are
used to control infections in the ear canals.
Shampoos to remove excess oil from the skin can be essential for some cases, and
anti-yeast wipes are helpful for the skin fold areas and infections involving the feet.
Weight loss is often recommended in obese animals with excessive skin folds. Surgical
procedures are sometimes used to eliminate deep folds around the lips and beneath the
eyes in cases that become chronic in nature – these patients can show remarkable
improvement from life-long conditions.