Malassezia Otitis in Dogs and Cats – Vet Diagnosis, Treatment, and Prevention for 2025 🧫🐶🐱

Malassezia otitis is a common, irritating yeast infection of the ear canal that affects both dogs and cats. In this detailed 2025 guide, Dr Duncan Houston walks pet owners through how this condition develops, how it’s diagnosed, and the most effective treatments available—along with tips to prevent it from coming back. 🦻🧼

🔬 What Is Malassezia Otitis?

Malassezia pachydermatis is a yeast organism that normally lives on the skin and in the ears of pets. It only becomes a problem when conditions in the ear change—like increased moisture, wax, or inflammation. This shift allows the yeast to multiply uncontrollably, leading to infection and discomfort. 🦠

⚠️ Why Does It Happen?

Yeast overgrowth often occurs as a secondary issue to other health conditions. Some primary causes include:

• 🐾 Allergies (atopic dermatitis or food hypersensitivity)
• 👂 Narrowed ear canals (common in certain breeds)
• 🌊 Excessive moisture or oil in the ear canal
• 🔁 Recurrent bacterial ear infections

Studies also show that bacteria and yeast may coexist in ear infections, making treatment a little more complex. Dual therapy may be required in such cases. 📊

🐶🐱 Who Gets Malassezia Otitis?

It’s more common in dogs but can also occur in cats. Pets of any age or sex can be affected. Certain breeds with floppy ears or high secretory glands are particularly at risk. 🧬

🔍 Signs of a Malassezia Ear Infection

• 🟤 Increased wax and dark discharge
• 👃 Musty, yeasty odor from the ears
• 🐾 Persistent scratching or rubbing at the ears
• 🤯 Head shaking
• 📉 Hair loss on the ear flaps
• ⚫ Swelling, ulceration, or thickened ear skin
• 🔴 Redness or hyperpigmentation
• 💥 Aural hematomas from violent head shaking
• 🦻 Pain and potential hearing loss

🧫 How It’s Diagnosed

Your vet will start with a thorough ear exam and may observe:

• 🧴 Waxy, dark brown debris
• 🔴 Redness and swelling
• 🦠 Musty or unpleasant smell

To confirm diagnosis, your vet will perform ear cytology—swabbing debris and examining it under a microscope. A high count of Malassezia cells confirms the infection. 🧪

If the ears are too painful or swollen, sedation or general anesthesia may be required to perform a proper examination and cleaning. 😴

💊 Treatment Plan

1. Ear Cleaning

🧼 Removing debris is essential for medication to reach the infection site. Your vet may advise:

• Vet-performed deep ear flush under sedation
• Gentle at-home cleaning using vet-approved solutions

2. Topical Antifungal Medications

These are usually applied directly into the ear canal. They may be in the form of:

• Drops
• Ointments
• Single-dose extended-release gels (in some cases)

3. Systemic Treatments

In chronic or recurrent cases, oral antifungal medications may be prescribed to tackle deeper infections. 💊

4. Addressing Underlying Causes

Without treating the root cause—such as allergies—Malassezia infections will keep coming back. Your vet may recommend:

• Allergy testing and management
• Food trials to detect sensitivities
• Managing hormone imbalances

📅 Treatment Duration

Therapy usually continues for 7–14 days, but it must be tailored to each case. Your vet will recheck your pet's ears to confirm the infection is gone before stopping treatment. ❗

🧬 What Happens If It’s Not Treated?

Untreated Malassezia otitis can result in:

• Proliferation of the ear lining (excess tissue growth)
• Scarring or narrowing of the ear canal
• Middle or inner ear infections
• Permanent hearing damage or neurological signs

🧽 At-Home Prevention Tips

• 🧼 Regular ear cleaning with vet-approved products
• 🚫 Avoid moisture buildup—dry ears after swimming or bathing
• 📆 Routine ear checks, especially for high-risk breeds
• 🥗 Manage diet and allergies
• 🐶 Regular vet visits for chronic or recurrent cases

📊 Common Breeds at Risk

• 🐶 Cocker Spaniels
• 🐩 Poodles
• 🐕 Basset Hounds
• 🐾 Bulldogs
• 🐱 Devon Rex & Persian Cats

📝 Summary: Key Facts

• 🔍 Malassezia is a common yeast in pet ears—becomes pathogenic when conditions change
• 🩺 Diagnosis requires cytology for confirmation
• 💊 Treatment includes cleaning, antifungals, and addressing root causes
• 🔄 Without solving the underlying issue, infections will return

📲 When to Contact Ask A Vet

If your dog or cat has itchy, smelly, or crusty ears, don’t delay. Early diagnosis and proper treatment prevent serious complications. 🐾

• 📸 Share ear photos through the Ask A Vet app
• 📋 Get personalized antifungal and allergy management advice
• 👩‍⚕️ Access licensed vets for second opinions and long-term care strategies

Download the Ask A Vet app today and get expert support for recurring yeast infections and more! 🐶🐱🧴