Why is my dog or cat scratching their ears?
Ear irritation is common and treatable — but it rarely clears on its own and tends to get worse and more painful.
Book a vet visit rather than waiting if there's odour, discharge or pain. Seek prompt, same-day care if you see signs the deeper ear may be involved:
- A head tilt, loss of balance, circling, or flicking eye movements
- Facial droop, or a suddenly painful ear your pet won't let you near
- A swollen, fluid-filled ear flap (an aural haematoma)
- Sudden severe pain, bleeding, or a rapidly worsening ear
Ear scratching, head-shaking, odour or discharge usually points to otitis externa — inflammation of the outer ear canal — one of the most common problems in dogs and cats. It's typically driven by parasites (ear mites, especially in cats), allergies, moisture, or bacterial/yeast overgrowth. It needs a vet, because the right treatment depends on the cause and on whether the eardrum is intact. Signs like a head tilt or loss of balance suggest deeper involvement and are more urgent.
- Head-shaking, smell, discharge and scratching usually mean an ear-canal problem.
- Common drivers: ear mites (especially cats), allergies, moisture, and yeast/bacteria.
- Never put cotton buds, hydrogen peroxide, vinegar or unprescribed drops into the ear.
- Head tilt, balance loss, facial droop or a swollen ear flap need prompt veterinary care.
What ear scratching and head-shaking mean
The most common ear disorder in dogs and cats is otitis externa — inflammation of the external ear canal. Typical signs are head-shaking, a foul odour, redness, swelling, scratching, discharge and scaly skin; the ear can be itchy or painful, and one or both sides may be affected.
Ears are also easy to make worse. Vigorous head-shaking can burst a blood vessel in the ear flap, creating a swollen, fluid-filled aural haematoma. And because the wrong product in an ear with a ruptured eardrum can cause harm, ear problems really do need a vet to look inside with an otoscope rather than home treatment.
Common causes to consider
These are categories a vet thinks through — not a diagnosis of your pet:
- Ear mites — a very common cause, especially in cats, kittens and newly adopted animals.
- Allergies — environmental (atopy) or food allergy often underlie recurrent ear disease.
- Bacterial or yeast overgrowth — frequently secondary, thriving in a warm, moist canal.
- Moisture — water trapped after baths or swimming.
- Foreign material — a grass seed or debris in the canal.
- Ear shape — some dogs' ear conformation predisposes them.
- Deeper infection — otitis media/interna (middle/inner ear), often after recurrent outer-ear infections.
Dogs vs cats
In cats, ear mites are a leading cause, particularly in kittens and recently adopted cats, and inflammatory polyps can also affect the ear. In dogs, allergies are a very common underlying driver of repeated ear infections, and ear shape can play a role. In both species, recurrent outer-ear infection can progress to the middle or inner ear — and because facial nerves pass nearby, deeper disease can cause a head tilt, balance problems or facial changes.
Heat and humidity, and water trapped after monsoon-season baths or swimming, create the warm, moist canal that yeast and bacteria love — so ears that get wet are worth drying gently at the opening (never poking inside). For outdoor and community animals, ear mites spread easily through close contact, so a scratchy, head-shaking cat in a multi-cat environment is worth checking.
What to check, and what you can safely do
Before and during a vet call, it helps to note:
- One ear or both, and how long it's been going on
- Odour, discharge (and its colour), redness or swelling
- How painful the ear is — does your pet resist it being touched
- Head-shaking, rubbing the ear on the floor, or tilting the head to one side
- Any balance problems, circling or unusual eye movements
- A soft, swollen ear flap (possible haematoma)
Safe to do
- See your vet so the ear can be examined with an otoscope and the cause identified.
- Keep the ear dry; after baths or swimming, gently dry the opening only.
- Use only ear cleaners or medication your vet has prescribed, exactly as directed.
- Treat every pet in the home if mites are diagnosed, as advised by your vet.
- Address underlying allergies with your vet to prevent repeat infections.
Do not
- Put cotton buds (Q-tips) into the ear canal — they push debris deeper and can damage the eardrum.
- Use hydrogen peroxide, vinegar, alcohol or oils in the ear — these irritate an inflamed canal.
- Use leftover or another pet's ear drops — the wrong product can harm an ear with a ruptured eardrum.
- Ignore a head tilt, balance loss or facial droop — these need prompt care.
- Let a swollen ear flap go untreated.
When to see a veterinarian
Routine / prompt appointment: scratching, head-shaking, odour or discharge without neurological signs — get it checked before it worsens or becomes chronic.
Same day: a very painful ear, a lot of discharge or bleeding, a swollen ear flap (haematoma), or an ear that's rapidly getting worse.
Urgent: a head tilt, loss of balance, circling, flicking eye movements or facial droop — signs the middle or inner ear may be involved.
What the vet may check
Your vet will examine the ear canal with an otoscope — checking whether the eardrum is intact — and usually look at a sample of the discharge under the microscope (cytology) to see whether mites, yeast or bacteria are involved. That guides safe, targeted treatment. For recurrent ear disease, they'll look for an underlying cause such as allergy, and for deeper infections may recommend further imaging.
Frequently asked questions
Can I clean my pet's ears at home?
Only with a cleaner your vet recommends, and never with cotton buds pushed into the canal. If the ear is painful, smelly or discharging, it needs to be examined first — cleaning the wrong way, or with the wrong product, can make things worse.
Is it safe to use hydrogen peroxide or vinegar in the ear?
No. These can irritate an already-inflamed canal and worsen the problem. Use only vet-prescribed products, and only once the eardrum has been checked.
My pet keeps getting ear infections — why?
Recurrent ear infections usually have an underlying cause — commonly allergies in dogs, or mites in cats. Treating only the visible discharge gives short-term relief; finding and managing the root cause is what prevents repeats.
What does a head tilt mean?
A head tilt, wobbliness or flicking eye movements can indicate that the middle or inner ear is involved, which is more serious than a simple outer-ear infection. It needs prompt veterinary assessment.
Are ear mites contagious to my other pets?
Yes — ear mites spread easily between animals in close contact, so your vet may advise treating all pets in the household. They don't typically cause lasting problems in people.
My dog's ear flap is suddenly swollen and squishy — what is it?
That may be an aural haematoma — a blood blister in the ear flap, often from vigorous head-shaking due to an underlying ear problem. It needs veterinary treatment, both for the swelling and the cause behind it.
Sources
- SourceMerck Veterinary Manual — Ear Infections and Otitis Externa in Dogs. merckvetmanual.com
- SourceMerck Veterinary Manual — Otitis Externa (External Ear Infection) in Cats. merckvetmanual.com
- SourceMerck Veterinary Manual — Otitis Media and Interna in Animals. merckvetmanual.com