Derm Spotlight: Why Do Dogs Develop Yeast Infections On Their Skin?

Many dogs develop yeast infections on their skin caused by the organism Malassezia pachydermatis. A few of these organisms on the skin is considered normal. However, high numbers of this yeast can cause the pet to develop a bad smell and can increase licking, scratching, chewing, etc. An underlying skin disease such as hypothyroidism or allergic dermatitis can cause this yeast to overgrow on the skin. With continued exposure, many allergy dogs will develop a hypersensitivity/allergy to this yeast over time. So, even low numbers of yeast can create a lot of itch.

Malassezia pachydermatis often overgrows on the paws, between the toes, and in the ears. To confirm that your dog has a yeast infection, we use clear scotch tape to pick them up from the skin and make a slide for microscopic examination. The Malassezia sp. looks like purple “peanuts” or “foot prints” when examining them with a microscope. Please see the example below.

A yeast infection on the skin or in the ear can cause itchy and inflamed skin. A waxy type crust may be present. They can also develop a distinctive musty type odor. These infections are often treated with oral antifungal drugs, ear drops, shampoos and/or wipes to decrease the numbers back to normal/low numbers. If this condition occurs again and again than an underlying cause such as allergies should be investigated.

If you suspect your dog has developed a yeast infection please visit appointments on our website to schedule an appointment.

Sources:

1. Campbell, KL, Griffin, CE, Miller, WH. Muller & Kirk’s Small Animal Dermatology, 7th edition.  Elsevier St. Louis Missouri 2013.  Pages 243 – 249.
2. Hnilica, KA. Small Animal Dermatology, 3rd edition.  Elsevier St. Louis Missouri 2011.  Pages 83 – 90.