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Home > Dogs > Malassezia Dermatitis (Yeast Infections) in Dogs: Causes, Treatments, Prevention

Malassezia Dermatitis (Yeast Infections) in Dogs: Causes, Treatments, Prevention

sick dog with inflammation itching

Malassezia dermatitis is a common skin condition also known as yeast dermatitis. It’s caused by the Malassezia pachydermatis fungus, which is normal to have on the skin. However, problems arise when it grows excessively and leads to inflammation, (a.k.a. dermatitis). This condition can be quite itchy for your dog and requires long-term treatment. That said, most dogs will recover just fine, and the itchiness should abate in the first week of treatment.

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How Do Dogs Get Malassezia Dermatitis?

Dog with yeast infection
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The Malassezia fungus is present on dogs’ skin, and under normal conditions, it never causes a problem. However, should the immune system take a hit, this fungus might seize the opportunity that the weakened immune system represents for infection. This enables the fungus to multiply, leading to a yeast infection. Infections of this nature are known as opportunistic infections, and they can be difficult to prevent.

Sometimes, the immune system may be repressed due to medications that the dog is taking, such as corticosteroids. Other dogs might have immune deficiencies that lead to a poor ability to fight off a yeast infection. Fortunately, yeast dermatitis is not contagious, so it’s not something that your dog can contract from another dog or pass on.

Certain canine breeds seem to experience higher rates of yeast dermatitis than others.

Common Signs of Yeast Dermatitis

Knowing the signs of yeast dermatitis can help you catch it early and get a headstart on treatment.

The most common signs of this condition include:
  • Itchiness
  • Red skin
  • Dog emitting a musty odor
  • Increased dark pigment in the skin
  • Chronic ear infections
  • Skin becomes thick
  • Crusty, flaky skin with scales

Diagnosing Malassezia Dermatitis

dog scratching ear
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Your vet can diagnose this skin condition by obtaining a skin sample and examining it under a microscope.

There are several ways for them to take this skin sample, including:
  • Skin Biopsy: This is the most invasive option, but it also offers the most complete diagnostic information. For a skin biopsy, a biopsy punch is used to take a small piece of the dog’s skin.
  • Cotton Swab Sample: A moistened cotton swab is rubbed against the skin to collect yeast for examination.
  • Impression Smear: A microscope slide is pressed directly against the dog’s skin to collect yeast samples.
  • Acetate Tape Preparation: A piece of clear tape is adhered to the skin. The yeast samples stick to the tape upon removal.
  • Skin Scraping: A sharp blade is used to scrape off the top layer of skin, along with the yeast samples that will be examined.

Treating Yeast Dermatitis

Dog with yeast infection
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Depending on how serious your dog’s dermatitis infection is, they might receive treatment in the form of oral medication, topical treatments, or a combination of the two.

Oral Medication

Oral medications tend to be used for the most severe and repetitive cases of Malassezia dermatitis. Antibiotics may also be required to treat bacterial skin infections that commonly accompany dermatitis. Treatment by oral medication lasts for several months. Close monitoring of your dog’s blood is required with such medications because they can have serious side effects.

Topical Treatments

Medicated shampoos are commonly used as a topical treatment for yeast dermatitis. If your dog has particularly oily skin, they might need to be washed with a shampoo that has benzoyl peroxide or selenium sulfide in it to get the grease off before bathing with an anti-fungal shampoo with ketoconazole, chlorhexidine, or miconazole as an active ingredient.

When washing your dog with an anti-fungal shampoo, you must allow the shampoo to stay on the skin for 10 minutes or more. Treatment will need to be repeated twice each week for as long as 12 weeks, depending on the severity and persistence of the infection.


Final Thoughts

Yeast dermatitis—or Malassezia dermatitis, as it’s scientifically known—is a fungal infection of the skin that occurs when a dog’s immune system becomes compromised. It can range in severity from mild to extreme and seems to affect certain breeds more than others. Treatment can take the form of oral medication or anti-fungal shampoos, though dogs with severe yeast dermatitis will likely require both.

It’s a treatable condition, but if left untreated, it can severely impact your dog’s quality of life.

Featured Image: Kittima05, Shutterstock

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