What causes yeast infections in dog ears?

Is your dog or cat suddenly shaking their head? Are they scratching at their ears, or are they looking red? Your furry friend may have an ear infection. Certain factors can upset the balance of the ear environment. But what causes ear infections in cats and dogs exactly? Let’s get into that and some common treatments because it helps to know how you can prevent these from recurring in your pet.

Yeast Overgrowth is the Enemy

Yeast naturally resides in the environment or microbiome of the ears and skin. Certain factors in your pet’s microbiome help regulate yeast growth to create a healthy balance in the ear. But that balance can be disrupted when underlying factors cause inflammation in the ear. Inflammation can then cause swelling and the glands to over-secrete. This process leads to a moist environment in the ear canal. And because yeast thrives in a dark, moist environment, yeast overgrowth ensues. Overgrowth leads to dark brown discharge, an unpleasant odor and scratching at the ears. 

Environmental Allergies’ Role in Ear Yeast Infections

Several underlying conditions can cause an imbalance in the skin microbiome and lead to yeast overgrowth. Allergies are one of them, and skin allergies are among the most common causes of ear yeast infection in dogs and cats. Your pets can be allergic to things in the environment, food or a combination of both. Exposure to an allergen causes redness, swelling and increased secretion of the skin glands. 

Parasites’ Role in Ear Yeast Infections

Ear mites are the most common parasite that can contribute to yeast infections. Even though they can occur in dogs, they most commonly occur in cats. These tiny insects like to live and reproduce in the ear canal, causing significant irritation and inflammation. This disrupts the delicate balance of the ear canal’s microbiome.

Anatomy of the Ear and Other Contributors to Ear Yeast Infections

This is more likely to affect dogs than cats. Dogs with floppy ears or a lot of hair around or in their ears can be predisposed to ear yeast infections. Those floppy ears (cute as they are!) that aren’t well ventilated and are extra hairy can trap moisture, a condition that’s favorable for yeast overgrowth. Pets who are frequent swimmers can also be more prone to ear infections because of the constant exposure to moisture.

Best Way To Treat an Ear Yeast Infection 

To effectively treat your pet’s ear infection, find out what is disrupting the environment of the ear. Your veterinarian can perform tests using the discharge from the ears to confirm an infection. An ear swab cytology test can help determine if there are ear mites, yeast or a bacterial infection present. Based on those results, the appropriate treatment can be administered.

Restore the Microbiome

This is an essential part of holistic treatment, since there is an imbalance within the ear promoting yeast overgrowth. A product that can help restore the microbiome and prevent further growth of yeast is needed for short- and long-term care. Fortunately, Skout’s Honor’s probiotic line is scientifically-proven by third-party testing to stop and prevent the overgrowth of yeast. The Probiotic Ear Cleaner for dogs and cats is here to give your pet relief. It’s also great to use for maintenance to prevent a recurrence. Learn more about the full probiotics line here. 

What Have You Learned About Ear Yeast Infections?

Ear yeast infections can be managed and prevented when you restore balance to the microbiome. Having Skout’s Honor probiotic products in your arsenal can help maintain this balance. If you notice an ear issue with your cat or dog, let your veterinarian confirm that there’s an infection and treat it appropriately. Then make sure you get your hands on our probiotics to help prevent future infections.

Dr. Dwight Alleyne is a veterinarian who has over a decade of experience treating cats and dogs. He is also the creator of the Animal Doctor Blog, where he provides general health advice and pet product reviews.

References: 

Today’s Veterinary Nurse - Ear Cytology: Sampling, Processing, and Microscopic Evaluation

Fetch by WebMD - Yeast Infection in Dogs’ Ears: Causes, Treatment, and Prevention

Veterinary Partner - Ear Infection (Yeast Otitis) in Dogs

Yeast infections in dogs are a common problem, and can happen in and on several parts of the body. Even though yeast can grow anywhere on the skin, the areas that are most commonly affected include the ears, paws and skin folds.

Signs of a Yeast Infection

Dogs with ear yeast infections will have red, itchy ears that stink. They'll also likely have copious amounts of dark brown earwax. Dog ear yeast infections are very itchy, and affected dogs may constantly scratch their ears and shake their heads. They may also rub their ears along furniture or along the carpet — leaving their signature scent everywhere they rub — or groan when you scratch their ears.

If your dog has a skin yeast infection, their skin will be itchy and red. They may also experience hair loss and smell bad. If your dog is constantly chewing on their paws and the underside of the paw is red, swollen and smells bad, it could be a yeast infection. If a yeast infection goes on long enough, it can make the skin thicken and turn rough and black.

Causes of Yeast Infections in Dogs

Small numbers of malassezia (the main species of yeast that affects dogs) regularly live on healthy dogs. Normally, the immune system keeps yeast numbers in check. A yeast infection occurs when something compromises the health or balance of the skin or ears, causing yeast to overgrow. Conditions that can predispose dogs to yeast overgrowth include inhalant allergies; food allergies; hormonal conditions such as thyroid disease, diabetes and hyperadrenocorticism (Cushing Disease in dogs); and anything that negatively impacts the immune system.

In addition, dogs can develop a version of swimmer's ear. Yeast loves moisture. If your dog swims or plays in water a lot, or if you don't dry out their ears after bathing them, then the wet environment in the ear canal can predispose them to a yeasty ear infection.

What to Do If You Suspect Your Dog Has a Yeast Infection

If you think your dog is suffering from a yeast infection, then it's time to schedule an appointment with your veterinarian. If your dog does have a yeast infection, then that means two things:

• The overgrowth on your dog's skin or in your dog's ears needs to be addressed.
• The underlying condition that compromised the health of the skin or ears needs to be addressed.

If you don't correct or address the underlying condition, then even if you treat the yeast infection with anti-yeast medication, the problem will return. Treatment of the underlying cause depends on what it is. Allergies can be managed with special food, reducing exposure to allergies or allergy medication. Hormonal conditions can be managed with vet-prescribed medication.

How a Yeast Infection Gets Diagnosed

Vets diagnose yeast infections in dogs through a combination of physical exam findings and simple lab tests. Your vet will take a sample from the surface of your dog's skin or swab the ear, stain it and look at it under the microscope. Yeasts are easily identifiable under the microscope.

If your vet suspects an underlying condition that's contributing to your dog's yeast woes, then they'll likely recommend additional testing to determine the root cause.

Treating a Yeast Infection

If your dog has a yeast infection in their ears, then your vet will likely prescribe a combination of ear cleaning and topical medication that's applied to the ears. Cleaning ears is an important part of treatment, as it removes debris that can clog up the ear canal. If you've never cleaned your dog's ears, ask your vet to show you how it's done. Your vet may also prescribe a medicated lotion or cream to apply in your dog's ears once or twice daily after cleaning. Give this medicine as recommended by your vet, don't skip doses and don't stop early — even if your dog is doing better. Yeast infections like to hide deep in ear canals and if you stop too soon, you risk creating drug resistance and your dog getting another infection.

Skin yeast infections can be treated in multiple ways. Your vet might prescribe an oral anti-yeast medicine. However, topical treatments, such as prescription strength anti-yeast cream, lotion, shampoo and wipes, are also effective. If your dog has a yeast infection on their paws, medicated wipes or lotion can be effective.

If your dog has a widespread skin yeast infection, your vet may prescribe shampoo with ketoconazole. The shampoo needs to be in contact with the skin for five to ten minute before being rinsed off. If used properly and if the underlying cause is addressed, medicated shampoos are very effective in eradicating yeast overgrowth (and help your dog smell good too!). Be sure to follow your vet's instructions regarding any prescribed treatments.

Preventing Yeast Infections in Dogs

Yeast infections are a sign that something else is going on. The most effective way to prevent your dog from getting a yeast infection is to address any underlying causes. It can be as simple as drying your dog's ears after they go for a swim. Be sure to take your dog in for yearly examinations and annual bloodwork. That way, your vet can make sure to promptly treat any underlying issues, including hormonal problems or allergies. If your dog has a food allergy, talk with your vet about trying a prescription food that either has limited ingredients or is hypoallergenic.

Dr. Sarah Wooten

A 2002 graduate of UC Davis School of Veterinary Medicine, Dr. Sarah Wooten is a well-known international speaker in the veterinary and animal health care spaces. She has 10 years experience in public speaking and media work, and writes for a large number of online and print animal health publications. Dr. Wooten has spoken in the veterinary education space for 5 years, and speaks on leadership, client communication, and personal development. Dr. Wooten is also a certified veterinary journalist, a member of the AVMA, and has 16 years experience in small animal veterinary practice. In addition to being a speaker, author, veterinarian, and co-creator of the wildly popular card game 'Vets Against Insanity', she co-owns Elevated Eateries Restaurant group in Greeley with her husband of 21 years, and together they are raising 3 slightly feral mini-humans. When it is time to play, she can be found skiing in Colorado, diving with sharks in the Caribbean, or training kenpo karate in her local dojo. Go big...or go home.