Does My Dog Have an Ear Infection? Causes, Treatment, and When to See the Vet

Ear infections (otitis externa) are common in dogs and cause head shaking, odor, redness, and discharge. Learn signs, likely causes, home-first steps and when to seek veterinary care.

Does My Dog Have an Ear Infection?

Ear infections (otitis externa) are one of the most frequent reasons dogs see a veterinarian. They can be uncomfortable and, if left untreated, lead to chronic issues or spread deeper into the middle or inner ear. This guide explains typical signs, the most likely causes, what you can safely do at home, when to see the vet, and how infections are treated and prevented.

What is otitis externa?

Otitis externa means inflammation of the external ear canal — the part you can see and the tube that runs from the opening of the ear to the eardrum. It is usually caused by an underlying problem (allergy, moisture, foreign body, etc.) with secondary overgrowth of microbes (yeast or bacteria). Left untreated, it can become painful and progress to otitis media or interna (middle or inner ear disease).

Common signs of an ear infection

Look for any combination of these signs. Not every dog shows all of them.

• Frequent head shaking or head tilt
• Scratching at one or both ears
• Red, swollen ear flap (pinna) or ear canal
• Odor coming from the ear
• Brown, yellow, or black discharge
• Crusts or scabs around the ear opening
• Pain when the ear is touched, or flinching
• Hearing loss or lack of response to sounds
• Behavioral changes (irritability, hiding)

Differential diagnosis — common causes ranked by likelihood

Note: ranking is approximate and depends on your dog’s age, breed, and history.

Definitive diagnosis usually requires a veterinary exam with otoscopic evaluation and cytology of ear discharge; sometimes culture or imaging is needed for chronic or refractory cases (Merck Veterinary Manual).

When to see a vet immediately

Seek urgent veterinary care if you notice any of these:

• Severe pain or your dog cries when the ear is touched
• Facial paralysis (drooping face on one side), head tilt, or loss of balance
• Blood or large amounts of pus from the ear
• High fever, collapse, or signs of systemic illness
• A rapidly expanding swollen ear flap (possible aural hematoma)

Is it an emergency, urgent, or okay to wait?

• Emergency: severe pain, neurological signs (head tilt, circling, facial paralysis), bleeding, collapse. Go to an emergency veterinary clinic.
• Urgent (see within 24–48 hours): smelly discharge, worsening pain, persistent head shaking, bright red swollen ear, or if symptoms don't improve after 48–72 hours of simple at-home measures.
• Wait-and-see (monitor closely for 48 hours): mild rubbing or brief head shaking, no discharge, and no pain — but check daily and seek veterinary advice if signs persist, worsen, or recur.

What your vet will do at the appointment

A typical veterinary workup includes:

• Full history (duration, prior episodes, water exposure, medication use, other skin or allergy signs)
• Physical exam and otoscopic inspection of the canal and eardrum (may require sedation if painful)
• Cytology (microscopic exam of ear discharge) to look for yeast, bacteria, or mites
• Culture and sensitivity if the infection is chronic, nonresponsive, or caused by unusual bacteria
• Imaging (X‑ray, CT) or referral for surgery in severe chronic disease
• Screening for underlying causes (allergy testing, food trial, or blood tests for endocrine disease) if infections recur

Typical veterinary treatments

Treatment targets both the infection and the underlying cause:

• Cleaning: professional flushing of the ear canal if there is heavy debris. This may require sedation.
• Topical medications: most uncomplicated cases respond to prescription ear drops that combine an antibiotic, antifungal, and anti‑inflammatory steroid.
• Systemic drugs: oral antibiotics or antifungals for severe or deep infections; pain control (NSAIDs) when needed.
• Address underlying disease: allergy management (medications, immunotherapy, or diet changes), control of moisture, and treatment of endocrine disease if present.
• Surgery: aural hematoma repair or, in end-stage chronic disease, procedures such as total ear canal ablation with lateral bulla osteotomy (TECA-LBO).

Home care steps you can safely do

If your dog has mild signs and you are waiting for a vet appointment, these safe steps can help:

• Keep the ear dry and clean the outer ear gently. Use a soft cloth or cotton ball — never insert cotton swabs or your finger deep into the canal.
• Dry ears thoroughly after swimming or bathing using a towel and, if recommended by your vet, a veterinary ear-drying solution.
• Avoid pouring human ear drops, alcohol, hydrogen peroxide, or undiluted vinegar into the ear — these can irritate the canal and delay healing.
• Don’t attempt to remove large foreign bodies or to lance a swollen ear flap (aural hematoma) at home.
• Follow the exact application instructions if your vet prescribes ear drops: dose, frequency, and how to massage the base of the ear to move medication into the canal.
• Finish the full prescribed course even if signs improve quickly; stopping early can lead to recurrence.

Preventing future ear infections

Prevention focuses on reducing the risk factors that allow microbes to overgrow:

• Regular ear checks: look inside the ear openings weekly for redness, smell, or debris.
• Dry ears after swimming or baths; consider ear-drying solutions recommended by your vet for frequent swimmers.
• Routine cleaning only if advised: some dogs with normal ears need no regular cleaning; others with recurrent disease benefit from scheduled cleaning with a vet-approved product.
• Manage allergies: work with your vet to identify and control atopic disease or food allergies — effective allergy control reduces ear infections.
• Keep long-haired ear canals trimmed by a groomer or vet if hair traps moisture and debris.
• Avoid excessive bathing and the use of harsh shampoos that can dry and irritate the skin.

Red Flags — Seek Emergency Care

Get immediate veterinary or emergency clinic attention if any of the following occur:

• Your dog stops eating, vomits repeatedly, or shows signs of systemic illness
• Severe ear pain, screams or cries when ear touched
• Facial paralysis (drooping whisker line, inability to blink on one side)
• New head tilt, circling, or loss of balance
• Large area of swelling in the ear flap that appeared quickly (aural hematoma) or active bleeding

Key takeaways

• Ear infections are common; signs include head shaking, scratching, odor, discharge, and ear redness.
• The most likely underlying contributors are allergies, moisture, yeast, and bacteria; accurate diagnosis requires veterinary exam and cytology (Merck Veterinary Manual).
• Mild, very recent symptoms without pain may be monitored briefly, but persistent, smelly, or painful ears should see a vet within 24–48 hours.
• Seek immediate care for severe pain, neurological signs (head tilt, facial paralysis), bleeding, or systemic illness.
• Safe home care includes gentle external cleaning, drying after swimming, and following your veterinarian’s instructions for any prescribed ear medications. Never attempt deep cleaning or use human products without veterinary approval.
• Prevent recurrence by managing allergies, keeping ears dry, and scheduling regular checks with your veterinarian.

Sources: Merck Veterinary Manual: Otitis Externa in Dogs; standard veterinary dermatology references.

Frequently Asked Questions