Malassezia yeast can infect the skin and/or ears of dogs and sometimes cats that have other types of skin disease. Infection is itchy and uncomfortable.
Yeast are, by definition, a spore-like form of fungi. Malassezia is a yeast organism that frequently populates the skin of the dog and cat. In fact, Malassezia are present even on the skin of healthy dogs and cats. However, when the skin becomes damaged, the changes in the skin give the yeast the opportunity to reproduce and infect the skin in higher numbers. The yeast organisms can infect the ears of the dog and cat as well.
Malassezia Yeast Infections in Dogs and Cats
Yeast infections involving Malassezia rarely occur in either dogs or cats without an underlying form of skin disease. Though the organisms are capable of causing disease in damaged skin, they are not particularly virulent in the absence of pathology.
Yeast infections due to Malassezia occur frequently in dogs and can occur in cats but are less common in the feline species.
Any type of skin disease can predispose a dog or cat to a Malassezia yeast infection. Some of the more common predisposing causes are:
- flea allergies
- food allergies
- inhalant allergies (also known as atopy)
Other diseases that affect the skin can sometimes be responsible for causing Malassezia yeast infections also. These diseases include demodectic mange, autoimmune skin disease and other types of skin disease.
Symptoms of Canine and Feline Malassezia Yeast Infections
The most common and easily recognizable symptom of yeast infection in dogs and cats is intense itchiness.
Malassezia can infect both the skin and the ears of the canine and feline. In dogs, yeast infection with Malassezia is an extremely common secondary infection. Yeast infection is less often diagnosed in cats but in either species, infection can be problematic. Without treatment of the yeast infection, the underlying disease is unlikely to respond well.
Commonly seen symptoms are those seen with many other skin diseases and include reddened or inflamed skin, open sores, scabs, hair loss and, in more chronic cases, thickened skin. Yeast infections often cause a foul skin odor as well.
In the ears, Malassezia yeast infection causes similar symptoms. The dog may shake his head, scratch at his ears or tilt his head. The ears may have a black to brown colored waxy discharge and may also have an odor.
Treatment of Malassezia Yeast Infections in Dogs and Cats
Yeast infection with Malassezia is treated in several different ways. Shampoos are frequently used although they may not be totally effective in and of themselves. Commonly used shampoos include benzoyl peroxide shampoos and those containing chlorhexidine. In addition, shampoos containing anti-fungal medications such as miconazole and ketoconazole may be used as well.
Topical medications used to treat small lesions include those containing acetic acid. A mixture of vinegar and water is often used to treat small areas of yeast infection also.
Antifungal medications such as ketoconazole given orally are usually the most effective means of treatment.
Any time a dog or cat develops a skin disease, secondary infection with Malassezia yeast is a possibility. When this occurs, your dog or cat may not improve until the yeast infection is controlled. Your veterinarian can perform simple skin tests to determine if your pet has a yeast infection.