Dog Ear Infection: Signs, Causes and What to Do

Last reviewed October 2026. This guide is educational and is not veterinary advice. If your dog is in pain or you are worried, call your vet. Some links are affiliate links: as an Amazon Associate, PetBoo earns from qualifying purchases at no extra cost to you.

⚡ Quick answer

A dog ear infection usually shows up as head shaking, scratching, redness, a bad smell and dark or yellow discharge. Ear infections are painful and rarely clear up on their own, so book a vet visit rather than reaching for a home remedy. The vet can look inside the ear, check the eardrum and test what’s growing before choosing treatment.

✅ Key takeaways

Common signs are head shaking, scratching, odor and discharge.
Causes include yeast, bacteria, allergies, mites and moisture.
Don’t put drops or home remedies in a painful ear before a vet checks the eardrum.
Never push cotton swabs deep into the canal.
Repeat infections often point to an underlying cause, such as allergies.

Short-coated brown dog portrait showing the ears — Take a look at your dog’s ears when they’re healthy, so you notice when something changes.

Signs of an ear infection in dogs

Sign	What you might notice	How urgent?
Head shaking or tilting	Frequent shaking, head held to one side	Book a visit
Scratching or rubbing	Pawing at the ear, rubbing on furniture or carpet	Book a visit
Odor	A yeasty, musty or sour smell	Book a visit
Discharge	Dark, waxy, yellow or bloody material	Book a visit
Redness or swelling	Red, hot or swollen ear flap or canal	Book a visit
Pain	Yelping, snapping when touched, reluctance to be handled	Same day
Balance problems	Stumbling, circling, eyes flicking side to side	Urgent can mean the infection has gone deeper

What causes dog ear infections?

A dog’s ear canal is L-shaped, which traps warmth and moisture. That’s a comfortable home for yeast and bacteria when something tips the balance.

Cause	Notes
Allergies	Food or environmental allergies are a leading underlying cause, especially for repeat infections
Moisture	Swimming and baths can leave water in the canal. See bathing tips
Ear shape	Floppy ears and narrow canals trap air and wax
Ear mites	Tiny parasites, more common in puppies, causing dark crumbly debris
Foreign material	Grass seeds or debris lodged in the canal
Hormonal or other conditions	Some illnesses make ears more vulnerable

Dogs with long, floppy ears or lots of ear hair are commonly affected, but any dog can get one. Poodles and some spaniels, for instance, often need regular ear checks. See our Poodle guide.

What the vet will do

Look into the ear with an otoscope to check the canal and eardrum.
Take a sample and examine it under a microscope to identify yeast, bacteria or mites.
Clean the ear if needed, sometimes with sedation if it is very painful.
Prescribe treatment, such as medicated drops or a cleaner, and sometimes oral medication.
Look for the root cause, especially if infections keep coming back.

Finishing the full course matters even if the ear looks better, and a recheck makes sure it has truly cleared.

What not to do

Don’t pour drops or home remedies into a sore ear before a vet checks the eardrum. Some products can harm a damaged eardrum.
Don’t use cotton swabs deep in the canal. They can pack debris down and cause injury.
Don’t use old leftover medication from another pet or an earlier infection.
Don’t ignore a recurring problem. Repeat infections need a root-cause workup.

Routine ear care at home

For healthy ears, a gentle routine helps. Only do this when your vet says your dog’s ears are healthy and recommends a cleaner.

Check the ears weekly for redness, odor and discharge.
If advised, fill the canal with a vet-approved ear cleaner, massage the base of the ear for about 30 seconds, then let your dog shake.
Wipe the visible part of the ear with cotton or gauze.
Dry the ears after swimming or baths.
Reward your dog so it learns that ear care is pleasant.

Grooming matters too, and our grooming basics guide covers the rest of the routine. If your dog also seems itchy elsewhere, ask about allergies and check flea and tick prevention. More general warning signs are in signs your dog may be unwell.

🛒 Ear care supplies (ask your vet first)

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🧠 Quick quiz

Why shouldn’t you put drops in a painful ear without seeing a vet?

If the eardrum is damaged, some products can cause harm. A vet can check first.

What can repeated ear infections point to?

An underlying issue such as allergies, which needs to be addressed alongside the ear.

Frequently asked questions

Can a dog ear infection go away on its own?

Rarely. Untreated infections tend to worsen and can lead to chronic problems, so see a vet.

What does a dog ear infection smell like?

Often yeasty, musty or sour, but any new, strong odor is worth checking.

Is a dog ear infection an emergency?

Usually not a life-threatening emergency, but pain, swelling, or loss of balance means a prompt visit.

Can I use hydrogen peroxide or vinegar in my dog’s ears?

Ask your vet first. Some home products can irritate the skin or harm a damaged ear.

How do I prevent ear infections in dogs?

Dry ears after swimming and bathing, check them weekly, treat underlying allergies and use a vet-approved cleaner if recommended.

Are ear infections contagious?

Infections caused by yeast or bacteria usually aren’t, but ear mites can spread between pets.

How long does treatment take?

Often one to several weeks depending on the cause and severity. Follow your vet’s instructions and attend any recheck.

Final thoughts

Ears are small, but a sore one makes a dog miserable. Learn what normal looks like, act quickly on the signs, and chase the cause if infections keep returning. For general background see the Cornell Riney Canine Health Center.

This article is educational and is not a substitute for veterinary advice.