Ear Yeast Infections in Dogs

Causes, Treatment, and Prevention

Chihuahua getting an ear exam.

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Ear yeast infections are very common in dogs. The moist environment of the ear is a prime breeding ground for fungal yeast that, when overgrown, creates infection. This causes itching, inflammation, and an unpleasant odor. Dogs with floppy ears are particularly vulnerable because their ears trap moisture. Ignoring infected ears can lead to painful skin crusting, so it's helpful to know how to spot—or sniff—the symptoms.

What Is an Ear Yeast Infection?

An ear yeast infection occurs when yeast species overpopulate the ear of a dog. Malassezia pachydermatis is the species of yeast that is typically seen in dog ears. This type of yeast is different than the yeast that is used to bake bread or that is found in probiotics. It is naturally found on the skin and ears of dogs in very small amounts but if the right conditions are present, it causes an infection. The ear canal and the ear flap itself can both be affected.

Symptoms of Ear Yeast Infections in Dogs


  • Shaking head
  • Scratching at ears
  • Painful ears
  • Red or swelling inside ears
  • Yeasty odor from the ears
  • Excessive ear wax or debris
  • Thickened ear flaps
  • Ear skin scaling
  • Drooping ear

Similar to a bacterial infection of the ear, a yeast infection usually causes a dog to shake its head and scratch at its ears. This is due to the irritation and inflammation that the infection causes. Your dog may also be reluctant to have its head and ears touched due to discomfort.

Inside the ear, redness, swelling, and thickening of the skin are indicative of a yeast infection. Scaling or crusting of the skin on the ear flap is also common, especially in severe or chronic cases. An odor similar to sour bread dough may be present as well as excessive, oily ear debris.

Dog ear flap with a yeast infection.

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Causes of Ear Yeast Infections

There are several causes of ear yeast infections in dogs. Some of the most common causes include:

  • Allergies: If a dog has an allergy to something in the environment or food then a yeast overgrowth may occur in the ear. The body reacts to the allergen with inflammation, and this, in turn, can cause the yeast to proliferate in the ear.
  • Ear mites: Ear mites, which feed off of a dog's ear wax, can cause irritation and inflammation in the ear. This can result in an overgrowth of yeast.
  • Moisture: An ear canal is a warm place, and yeast thrive in warm, moist environments. If water enters the ear canal and the ears do not properly dry out, yeast will reproduce and cause an infection. This often occurs after a dog gets a bath or goes swimming.
  • Ear deformities: Some dogs are born with abnormal ear canals or excessive ear tissue. Other dogs will develop ear issues over time due to trauma, recurrent infections, or other things. These deformities usually make it difficult for an ear to stay dry and instead trap moisture that helps to create an environment for yeast to grow in.
  • Tumors: Some tumors in the ear block the opening to the ear canal. This causes excessive heat and moisture to build up and encourages the overgrowth of yeast.

Some hormonal changes, antibiotic use, and other skin issues may also cause ear yeast infections in dogs.

Diagnosing Ear Yeast Infections in Dogs

If you suspect your dog has a yeast infection in its ears, then you should have it examined by a veterinarian. Your vet will use an otoscope to see inside the ear canal and make sure the eardrum isn't ruptured. A cotton swab will then be used to collect some of the ear debris for microscopic examination to see if yeast, bacteria, or both are present.

Treatment of Ear Yeast Infections in Dogs

Your vet will prescribe medicated ear drops and a cleaner to remove debris. These will be used for about two weeks. If the ear is especially painful, then anti-inflammatory medications may also be used.

Occasionally an ear yeast infection may be so painful for a dog that it will need to be sedated or anesthetized by your vet to perform the initial ear cleaning and treatment. Your veterinarian may also recommend some at-home remedies depending on the severity of the infection.

Prognosis for Dogs with Ear Yeast Infections

Yeast infections in dogs' ears are usually easy to treat with persistent treatment, but in dogs with predisposing characteristics, infections are likely to reoccur. Dogs with floppy ears, allergies, and ear deformities are at a higher risk of recurrent ear yeast infections. Dogs that like to play in water are also more likely to get a yeast overgrowth and have an infection.

How to Prevent Ear Yeast Infections in Dogs

The best way to prevent your dog from developing an ear yeast infection is to keep its ears clean and dry. An ear cleaner with a drying agent should be used after baths and swimming to help dry the ear canal. If your dog has allergies, your veterinarian may recommend certain foods and supplements to help support the skin and decrease inflammation.