Causes & Symptoms of Yeast Infections in Pets
Malassezia is a normal inhabitant of your dog's or cat's skin, but it becomes problematic only when it changes from a harmless to a pathogenic form. The precise causes of this transformation is unknown, although factors that suppress or imbalance the immune system are often involved. Some factors that may contribute to yeast infections include allergies to fleas, inhalant/contact allergies, food allergies, prolonged use of steroids or antibiotics, hormonal disorders like hypothyroidism or Cushing's Disease, cancer, chemotherapeutic drugs, and external skin parasites. Pets with excessive skin folds such as the brachycephalic breeds of dogs (Bulldogs, Pugs) are also at increased risk.
Concurrent bacterial skin infection also may cause an increased risk for yeast overgrowth. Yeast overgrowth will often result in increased oil production by the skin, causing increased itching that can create secondary sores, and providing an even more supportive environment for the yeast to thrive.
Symptoms of yeast infection may include intense itchiness, skin irritation, and inflammation, especially around the ears, between the paw pads and digits, and on the nasal folds, anal area, armpits, and neck. Skin redness, sores, and sticky discharge are often secondary to yeast overgrowth. Greasy coat and/or hair loss is also frequently seen, as well as foul-smelling, rancid skin. When occuring in the ears, yeast infections may lead to yellowish green, musty smelling discharge. Some breeds of dogs predisposed to yeast include West Highland White Terriers, Poodles, Basset Hounds, Cocker Spaniels, and German Shepherds.