Ear Disease in Dogs (Otitis Externa & Ear Infections)

What Causes Ear Disease in Dogs?

Common underlying causes of ear conditions include allergic skin disease, parasites, foreign material and other conditions that affect the ear environment. Ear infections rarely occur in isolation and are usually the result of a combination of underlying causes and contributing factors. In many dogs, particularly those with recurrent or chronic ear disease, an underlying condition such as allergic skin disease is present.

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 Dogs

Signs may vary depending on severity and duration, and may affect one or both ears. In many dogs, signs recur over time, particularly where an underlying condition has not been addressed.

• Head shaking
• Scratching at the ears
• Rubbing ears on furniture or the ground
• Redness or inflammation within the ear
• Discharge, which may be brown, yellow or black
• Odour from the ears
• Pain or sensitivity when the ears are touched
• Swelling or narrowing of the ear canal
• Hearing changes in more advanced cases

The pattern, severity and recurrence of ear disease often provide important clues to the underlying cause. These signs are commonly associated with ear problems or ear infections in dogs, particularly where inflammation and infection are recurring or persistent.

Why Ear Disease in Dogs Becomes Recurrent or Chronic

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

This can lead to a self-perpetuating cycle:

• An underlying cause (for example allergy) 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 infections more likely

As this cycle continues, the ear canal can become thickened, narrowed and less responsive to treatment. In advanced cases, this may progress to chronic ear disease requiring more intensive or long-term management.

How We Diagnose Ear Disease in Dogs

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 dog’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 dog’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 Dogs 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 the 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, including in-clinic or sedated ear flushes where required to remove debris and allow effective treatment
• Medications to reduce inflammation and discomfort
• Management of underlying allergy or skin disease
• Parasite treatment where relevant
• Long-term strategies to reduce recurrence and maintain ear health
• Surgical intervention in advanced cases where medical management is no longer effective

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

Related Conditions

Dog Allergies

Skin Infections in Dogs

Parasites in Dogs

Explore other common conditions in dogs here →