• Illustrated icon of microscopic malassezia yeast, a common cause of skin yeast infection

Malassezia: Yeast Infections in Dogs

Remember, we always recommend consulting with your vet for any of your dog's health concerns.

Malassezia cells under microscope

What is Malassezia and Yeast?

Yeasts are a type of fungus - singe-celled microscopic organisms that are naturally present in the environment and our digestive systems. They are beneficial in many ways, and were one of the first "domesticated" microorganisms - used in everything from bread and beer to drugs and dietary supplements.

Malassezia pachydermatitis is a form of yeast that dwells on canine skin; its cells have a round or peanut shape when seen under the microscope. Much like bacteria, yeast isn't harmful until an abnormal overgrowth occurs.

Photo via University of Adelaide, Mycology: Malassezia

Malassezia dermatitis on neck, chest, and forelegs of small dog being examined at vet's office

What Causes Yeast Skin Infections in Dogs?

Canine yeast infections and dermatitis are very common skin problems that are caused by the unchecked growth of Malassezia yeast. They can happen to any dog, but certain breeds are more prone to yeast infections than others.

Yeast infections tends to develop as a result of a change in the dog's skin condition, their immune system, or their environment. Some common causes include allergens and irritants (mold, dust, chemicals, etc), parasitic bites, certain food allergies, heat and humidity, and trapped moisture in areas with no airflow (i.e., ears and skin folds).

Yeast dermatitis in dogs can also arise as a secondary problem due to bacterial infection (aka pyoderma). Malassezia is believed to have a symbiotic relationship to the bacteria Staphylococcus pseudintermedius, which causes the majority of bacterial skin infections in dogs. Yeast cells can find haven when Staphylococcus creates a bacterial biofilm - a type of barrier that protects the microbes from antibiotics, cleaning solutions, and other threats.

Photo via Willows Veterinary Centre & Referral Service

Illustration of a chicken

Are There Foods That Cause Yeast Skin Infections in Dogs?

Certain proteins are often the food ingredients that cause allergic reactions, and chicken is the most frequent food allergen found to be correlated with yeast infections. A diet that is high in sugar and carbohydrates is also believed to be a contributing factor of yeast dermatitis and ear infections (otitis).

Determining your dog's food and skin sensitivities can be a tricky trial-and-error process, but if your dog suffers from chronic skin issues, it could potentially make all the difference in their overall health. It is best to consult with your veterinarian, as they can offer the proper guidance and tests to map out your dog's allergy sensitivities.

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    Dachshunds

  • Illustration of German Shepherd wearing sunglasses and lavender tie

    German Shepherds

  • Drawing of boxer dog with lavender sunglasses, lavender spiked collar, and lavender basketball at feet

    Boxers

  • Spaniels

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    Shih Tzus

  • Drawing of a basset hound wearing aviator goggles

    Basset Hounds

  • Labradors

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    Pitbulls

  • Drawing of English bulldog wearing lavender collar and propellor hat

    Bulldogs

Malassezia fungal infection on neck and chest of dog, with fur loss

Types of Yeast Infections in Dogs

Skin (Dermatitis)

Yeast dermatitis refers to a yeast infection of the skin. While it can spread across the body, yeast dermatitis tends to affect areas such as lip margins, skin folds, armpits, groin, vulva, and neck.

Yeast dermatitis is not contagious and cannot be spread to other dogs. It is typically caused by an increase in the natural oils produced on the skin due to allergies or a condition called seborrhea oleosa.

Dogs with deficient immune systems may contract chronic infections, as their bodies cannot effectively fight off the yeast cells. Some dogs can develop an allergic reaction to yeast and experience an extreme inflammatory reaction with even a small amount of yeast on the skin.

Photo via the Canadian Veterinary Journal.

Yeast infection in dog ear with redness and brown discharge

Ear (Otitis)

Yeast infections of a dog's ear (yeast otitis) cause a thick, odorous discharge and a whole lot of itching. They can occur in the external (otitis externa) or middle (otitis media) part of the ear, and dogs will scratch their ears and shake or tilt their heads for relief.

Yeast ear infections commonly develop in relation to food allergies, irritants or debris in the ear, thick hair in the ear, or in relation to other health issues such as hypothyroidism, diabetes, or an autoimmune disorder.

Breeds with long ears, such as spaniels, basset hounds, and labradors are more prone to these infections. Dogs that spend a lot of time in water - allowing for moisture to get trapped in the ear - are also more liable to contract a yeast ear infection.

Photo via the Cornerstone Animal Clinic of Dallas.

Closeup of bulldog paw with bacterial pyoderma infection and redness between toes

Paws

Dog paw yeast infections are extremely common and tend to occur in relation to environmental allergies or an irritant, like from dust, pollen, or grass. They will constantly lick and chew their paws, which can bring about redness, open sores, and further infection.

The damp, covered area between toes and paw pads and the region near the nail beds are especially susceptible. It shouldn't be forgotten that dogs perspire through their feet, so all-in-all their paws make for an excellent Petri dish for yeast and bacteria to grow.

On top of that, dog paws absorb contact almost constantly, so it's only a matter of time before the skin becomes damaged and the yeast that naturally dwells nearby can take over.

It's good to check your dogs paws regularly - especially if they're licking them more than normal - to make sure there isn't a hidden problem that's becoming worse.

Drawing of basset hound dressed as Sherlock Holmes with magnifying glass in mouth

Symptoms of Canine Yeast Infections

Yeast Otitis

  • Repetitively scratching ears and shaking head (ear infection)
  • Inflamed ear canals
  • Brown ear discharge with bad odor

Yeast Dermatitis

  • Severe itching (pruritis)
  • Hair loss (alopecia)
  • Scaly, greasy, skin (seborrhea) of yellow or gray color with strong musty odor
  • Crusts, pimples, or pustules
  • Inflammation, especially between skin folds, armpits, and groin
  • Patches of hyperpigmentation (dark, leathery, hardened skin)

Paw Yeast Infection

  • Excessive paw licking, biting, and chewing
  • Discoloration of the skin
  • Hair loss
  • General redness or "pinkness" between pads
  • Inflammation and/or infection of nails, with discoloration
Drawing of microscope, cotton swab, biopsy punch, scalpel, microscope slide, and yeast cells as seen under microscope to depict yeast infection diagnosis process

How Do You Test for Canine Yeast Infections?

Since yeast infections and dermatitis can be secondary issues, collecting samples is necessary to ascertain that there aren't compounding problems, such as bacterial infection. There are several sampling techniques to identify and diagnose yeast infections.

  • Cotton swab: A sterile swab is used to gather cells from the area. From there it can be transferred to a microscope slide, stained (so the cells can be easily seen), and examined, or sent as a culture to a lab for identification.
  • Acetate tape impression: A piece of clear tape is applied to the skin
  • Microscope slide impression smear: This saves a cotton swab or tape and simply presses the slide directly onto the area.
  • Skin scrape: A dull blade is used to scratch the skin and collect yeast organisms.
  • Skin biopsy: This technique uses a punch to collect a deeper skin sample. It is the most invasive form of testing, but it yields the most data. Skin biopsies may be administered when the yeast infections are chronic or unresponsive to treatment.
Yeast dermatitis on chest of mini-poodle dog lying on examination table

How Are Canine Yeast Infections Treated?

Medicated shampoos with selenium sulfide or benzoyl peroxide are typically used initially to "degrease" and cleanse the skin affected by a yeast infection. From there, bathing with anti-fungal shampoo with chlorhexidine, ketaconazole, or miconazole every 3-5 days for several weeks may be needed.

For localized dermatitis spots or a paw yeast infection, an antifungal ointment may be prescribed. For yeast otitis (ear infection), a medicated ear wash and topical steroid my be recommended to reduce inflammation. Alternatively, Lavengel may be able to help with paw and ear yeast infections, with no prescription necessary.

For severe cases of yeast infections, systemic oral anti-fungal medications such as ketoconazole, terbinafine, or fluconazole may be required. Dogs with yeast dermatitis will likely have a bacterial (pyoderma) skin infection, so antibiotics may be needed on top of the antifungals to clear the compound infection.

While these medications are effective, they call for prolonged use to eradicate the infection(s). This can put stress on the liver and have potentially harmful side effects.

Photo via Newtown Veterinary Specialists

What Home Remedies Can Help Prevent a Dog Yeast Infection?

We always recommend seeking veterinary attention if your dog has a yeast infection, especially since there may be other infection or complications present.

A few ways you can help prevent your dog from developing a yeast infection are:

  • Regular bathing, with attention to "sheltered" areas, such as between skin folds, under armpits, between toes and pads, etc.
  • Making sure your dog is completely dry after a bath or being in water.
  • Regular ear cleaning with a clean cloth, cotton ball, or ear wipes
  • Regular brushing/grooming to clear loose hair, dirt, and dead skin
  • Feeding them a healthy, well-balanced diet
  • Routine vet visits and staying up to date on vaccinations