Ear Disease in Cats (Otitis Externa & Ear Infections)

What Causes Ear Disease in Cats?

Common underlying causes of ear conditions include allergic skin disease, parasites, foreign material and other conditions that affect the ear environment. While infection is often present, it is usually secondary to an underlying condition.

Ear disease is best understood by considering the underlying causes and contributing factors:

While infection is often the most visible issue, it is usually not the underlying cause. Without identifying and addressing the primary driver, ear infections are likely to recur.

Signs of Ear Disease in Cats

Signs of ear disease in cats can vary and may affect one or both ears. In some cats, signs may be subtle and develop gradually, particularly in early or less severe disease.

Common signs include:

• Scratching at the ears
• Head shaking
• Discharge, which may be dark, waxy or malodorous
• Redness or inflammation within the ear
• Pain or sensitivity when the ears are touched

Some cats may also show:

• Subtle behavioural changes, such as reduced tolerance to handling
• Ear debris associated with mites, often dark and crumbly in appearance
• Reduced grooming tolerance around the head or ears

In some cases, signs may be mild, intermittent or less obvious, particularly compared to dogs.

The pattern, severity and recurrence of ear disease, as well as whether one or both ears are affected, can provide important clues to the underlying cause. These signs are commonly associated with ear problems or ear infections in cats, particularly where inflammation and infection are recurring or persistent.

Why Ear Disease in Cats Becomes Recurrent or Chronic

Ear disease often becomes recurrent when treatment focuses on the infection rather than the underlying cause. While infections may improve with routine or first-line treatment, they often return if the primary driver, such as parasites or allergic skin disease, is not addressed.

This can lead to a self-perpetuating cycle:

• An underlying cause triggers inflammation within the ear
• Inflammation alters the ear environment
• Bacteria and yeast overgrow
• Infection develops, causing further inflammation and discomfort
• Structural changes occur over time, making future episodes more likely

As this cycle continues, the ear canal may become chronically inflamed and less responsive to treatment. In some cases, this can progress to persistent or chronic ear disease requiring ongoing management.

Early identification of the underlying cause is important to reduce the risk of long-term or progressive disease.

How We Diagnose Ear Disease in Cats

Ear disease can be multifactorial and may resemble or overlap with other conditions, so a systematic approach is required to identify both infection and the underlying cause. Where referral is recommended, your cat’s assessment begins with a dermatology consultation, where our clinician reviews their history and previous treatments, and performs a thorough examination to assess the severity, distribution and progression of disease.

From here, our clinicians tailor a targeted diagnostic approach to your cat’s individual presentation.

A tailored diagnostic approach may include:

• Ear Examination and Procedures – including detailed otoscopic examination, and in some cases ear flushing procedures to remove debris and allow full assessment of the ear canal and tympanic membrane.
• Cytology and Fine-Needle Aspirates – used to identify bacteria, yeast and inflammatory cells, helping guide targeted treatment decisions.
• Airborne Environmental Allergy Testing – used in selected cases where environmental allergy is suspected as an underlying cause of recurrent ear disease, helping guide allergen-specific immunotherapy (ASIT).
• Biopsy and Dermatopathology – recommended in selected cases where ear disease is severe, chronic or not responding as expected.
• Ear swabs and culture – used in selected or treatment-resistant cases to guide targeted therapy
• Skin scrapings and parasite testing – where parasitic causes are suspected
• Advanced imaging (such as CT) – recommended in selected cases to assess deeper or chronic ear disease, particularly where middle ear involvement is suspected

Each step helps build a complete clinical picture, ensuring that treatment is based on an accurate diagnosis rather than repeated short-term management.

How Ear Disease in Cats Is Managed

Management depends on the underlying cause, severity of disease, presence of infection and whether the condition is acute or chronic. Effective treatment requires not only resolving infection, but also addressing the factors driving recurrence.

Depending on the diagnosis, treatment may include:

• Targeted treatment of bacterial or yeast infection
• Thorough ear cleaning and flushing procedures, often performed under sedation to remove debris and allow effective treatment
• Medications to reduce inflammation and discomfort
• Management of underlying allergy or skin disease
• Parasite treatment, particularly where ear mites are identified
• Surgical management in selected cases, such as removal of polyps or masses
• Long-term strategies to reduce recurrence and maintain ear health

For cats with recurrent ear disease, long-term management may be required. The goal is not simply to treat individual episodes, but to achieve more stable disease control, reduce recurrence and improve comfort and quality of life.

Related Conditions

Cat Allergies

Skin Infections in Cats

Parasites in Cats

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