Ear infections (otitis externa) are the second most common reason dogs visit veterinarians, after skin problems. Approximately 20% of dogs have some form of ear disease, and certain breeds (Cocker Spaniels, Basset Hounds, Labrador Retrievers, Golden Retrievers) have rates exceeding 50%. Recurrent ear infections are frustrating for owners and painful for dogs — but most can be prevented once the underlying cause is addressed.
Anatomy: Why Dogs Get Ear Infections
The canine ear canal is L-shaped — descending vertically then turning horizontally toward the eardrum. This design traps moisture, debris, and organisms in a warm, dark environment perfect for bacterial and yeast growth. Dogs with floppy ears, narrow canals, or excessive hair further restrict airflow.
Causes (Primary and Perpetuating)
| Primary Cause | Frequency | Key Feature |
|---|---|---|
| Allergies (atopy/food) | ~80% of chronic cases | Bilateral, recurrent despite treatment. Must address the allergy. |
| Foreign bodies | Common in active dogs | Sudden onset, one ear, head shaking. Grass awns (foxtails) most common. |
| Ear mites | Common in puppies | Dark brown crumbly discharge, intense itching |
| Hypothyroidism | Uncommon but important | Recurrent infections + weight gain, lethargy, skin changes |
| Moisture (swimming) | Common in water dogs | After swimming. Labradors, retrievers especially. |
Symptoms
- Head shaking and ear scratching
- Odor from ear (yeast smells musty/sweet; bacteria smells foul)
- Discharge (brown/yellow/bloody)
- Redness and swelling of ear flap or canal
- Pain when ears are touched
- Head tilt (may indicate middle/inner ear involvement)
Treatment
- Ear cytology: Microscopic examination of discharge to identify bacteria vs. yeast (treatment differs)
- Cleaning: Professional deep clean under sedation for severe cases; owner-performed maintenance cleaning with appropriate solutions
- Topical medication: Antibiotic + antifungal + anti-inflammatory (combination products: Otomax, Mometamax, Posatex, Claro)
- Systemic treatment: Oral antibiotics for severe/resistant infections; oral antifungals for deep yeast; steroids for severe inflammation
- Address underlying cause: Without treating the PRIMARY cause (usually allergies), infections WILL recur regardless of how well you treat each episode
Prevention
- Routine ear cleaning with appropriate pH-balanced ear cleaner (weekly for prone breeds)
- Dry ears thoroughly after swimming or bathing
- Manage underlying allergies (Apoquel, Cytopoint, immunotherapy)
- Regular veterinary ear checks (part of wellness exams)
- Don't over-clean (stripping natural protective oils makes infections worse)
Frequently Asked Questions
Why does my dog keep getting ear infections?
90% probability: underlying allergies. Each infection you treat is a symptom, not the disease. Until the allergic component is managed, infections will recur. Request allergy workup from your vet or veterinary dermatologist.
Can I use hydrogen peroxide to clean my dog's ears?
No. Hydrogen peroxide is irritating to the ear canal and can damage tissue. Use a veterinary ear cleaner designed for dogs (appropriate pH, drying agents, non-irritating surfactants).
