Dog Ear Infection Symptoms: 8 Signs to Watch For
Head shaking, odor, redness, and discharge are classic dog ear infection symptoms. Learn the signs one by one, yeast vs. bacterial clues, the causes, and the emergency red flags that mean you should call your vet now.
BVMS MRCVS
Medically reviewed by Dr. Pippa Elliott, BVMS MRCVS · Last reviewed
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Dog ear infection symptoms usually show up as frequent head shaking, ear scratching, a strong unpleasant odor, and redness or swelling inside the ear. Many dogs also develop a dark, waxy, or pus-like discharge and become sensitive when you touch the ear.
These signs mean the ear is inflamed and irritated, and they warrant a vet visit to identify the cause and start the right treatment.
Ear infections (medically called otitis externa when the outer ear canal is involved) are one of the most common reasons dogs are brought to the vet. The good news: caught early, most cases clear up. Left alone, they can become painful, chronic, and in rare cases spread to deeper structures.
This vet-reviewed guide walks through the signs one by one, how to tell yeast from bacterial infections, what causes them, and the red flags that mean you should call your vet now.
- 1The most common symptoms are head shaking, ear scratching, a strong odor, redness or swelling, and dark or pus-like discharge.
- 2Touch sensitivity, whining when the ear is handled, and holding one ear down are early behavioral clues.
- 3Head tilt, loss of balance, circling, rapid eye movements, or facial drooping are red flags for a deeper (middle or inner ear) infection: see a vet promptly.
- 4You cannot reliably tell yeast from bacterial from mites by looking; a vet uses ear cytology (a swab under the microscope) to diagnose.
- 5Never pour hydrogen peroxide, alcohol, or vinegar into an infected ear, and never use leftover or human medications.
- 6Early treatment is faster, cheaper, and less painful than treating a chronic, ruptured, or deep infection.
What are the symptoms of a dog ear infection?
The symptoms of a dog ear infection include persistent head shaking, scratching or pawing at the ear, a noticeable foul or yeasty odor, redness and swelling of the ear canal or flap, and abnormal discharge.
Dogs often tilt or hold the affected ear lower than the other and may flinch or cry when the ear is touched. Any combination of these signs is a reason to have the ear examined.
According to the Merck Veterinary Manual, the classic signs owners notice first are head shaking, scratching, and odor, often before any discharge is obvious.
Recognizing these early signs of an ear infection in dogs matters, because treating an early, mild infection is far simpler than treating one that has become chronic and thickened the ear canal.
Dog ear infection or just dirty ears?
A little light-brown wax with no smell, no redness, and no discomfort is usually just a dirty ear. An infection is different: it typically comes with odor, redness, swelling, pain, or heavy discharge, and the dog keeps shaking or scratching.
When in doubt, a gentle routine cleaning can help you tell them apart, and a vet swab settles it for sure.
If your dog just has normal wax buildup, our guide on how to clean a dog's ears walks through safe at-home cleaning. If there is odor, redness, or pain, skip the cleaning and see a vet instead, because cleaning an inflamed or possibly ruptured ear can make things worse.
The most common signs, one by one
Ear infections rarely show just one symptom. Learning to spot each sign, and how to spot an ear infection in your dog before it worsens, helps you act early. Here is what each of the most common signs looks like in real life.
Head shaking and ear scratching
Repeated, vigorous head shaking and constant scratching or pawing at the ear are usually the first things owners notice. The dog is trying to relieve the itch and irritation deep in the canal. Watch for scratching that leaves the ear flap red, scabbed, or losing hair.
Strong or unpleasant odor
A healthy ear has little to no smell. A distinct yeasty, sweet, or foul odor coming from the ear is a strong indicator of infection. Many owners can smell it from a few inches away, and it often gets worse as the infection progresses.
Discharge and buildup
Discharge can be waxy, dark brown to black, yellow, or resemble pus, as VCA Animal Hospitals notes. As a general clue, brown, waxy, chunky discharge is often associated with yeast, while yellow or greenish discharge more often points to bacteria. This is only a rough tendency, though.
Do not rely on the color alone to self-diagnose, because a swab under the microscope is the only way to know what is actually growing.
Redness, swelling, and pain
Look inside the ear flap: infected ears often show redness and swelling of the canal opening or flap. The ear may feel warm. Pain shows up as flinching, whining, or pulling away when you touch the ear, holding the ear or head at an angle, or reluctance to have the head handled at all.
Other signs to watch for:
- Rubbing the head and ear along furniture or the floor
- Hair loss, scabs, or raw skin around the ear from scratching
- A warm, tender ear flap or a soft, fluid-filled swelling of the flap (a possible aural hematoma)
- Crusting or scaling at the ear opening
That last one matters: violent head shaking from an ear infection can rupture a blood vessel in the ear flap and cause a dog ear hematoma, a swollen, fluid-filled flap that usually needs veterinary care of its own.
People often search for dog ear infection symptoms pictures to compare, but photos can be misleading because yeast, bacterial, and mite infections can look similar. Use images as a general reference only, and let a vet confirm the cause.
Yeast vs. bacterial ear infections: telling the difference by symptoms
You cannot reliably tell a yeast ear infection from a bacterial one just by looking or smelling. Both cause itching, odor, redness, and discharge.
The only dependable way to know is ear cytology, where a vet swabs the ear and examines the sample under a microscope to see whether yeast, bacteria, mites, or a mix is present. That result determines the medication.
There are, however, some general tendencies. The table below summarizes the common types of dog ear infections and the clues associated with each. Treat it as a rough guide, not a diagnosis.
| Type | Common symptom clues | How it is confirmed |
|---|---|---|
| Yeast (Malassezia) | Brown, waxy, greasy discharge; strong sweet or musty odor; intense itching; often linked to allergies or moisture | Ear cytology (swab under microscope) |
| Bacterial | Yellow, green, or pus-like discharge; strong foul odor; marked redness, swelling, and pain; may follow an untreated yeast or allergy issue | Ear cytology; sometimes culture for resistant cases |
| Ear mites | Dry, dark, crumbly coffee-ground debris; very intense itching; more common in puppies and cats | Microscopic exam to see mites |
| Mixed or chronic | Combination of the above; thickened canal; recurring despite treatment | Cytology plus workup for underlying cause |
| Deep (middle or inner ear) | Head tilt, loss of balance, circling, rapid eye movements, facial drooping, pain opening the mouth; often follows an untreated outer-ear infection | Exam plus imaging (X-ray, CT, or MRI); considered urgent |
Because yeast infections have their own nuances and often tie back to allergies, we cover them in depth in our dog ear yeast infection guide. If your vet confirms yeast, that is the place to understand the moisture and allergy connection and how to reduce flare-ups.
What causes ear infections in dogs?
Most ear infections in dogs are not caused by a single germ landing in the ear. They usually start with an underlying problem, most often allergies, that inflames the ear canal and creates a warm, moist environment where yeast and bacteria overgrow.
Understanding how dogs get ear infections helps explain why they so often come back if the root cause is not addressed.
Common underlying and contributing causes include:
- Allergies (food or environmental): the single most common underlying cause of recurring ear infections, per the American Kennel Club.
- Moisture from swimming or bathing that gets trapped in the canal
- Ear anatomy: floppy-eared breeds (Cocker Spaniels, Basset Hounds, Labradors) and dogs with narrow or hairy canals trap heat and moisture
- Foreign material such as grass awns or foxtails lodged in the canal
- Ear mites (especially in puppies)
- Endocrine disease such as hypothyroidism, and excessive or improper ear cleaning that irritates the canal
This is why chronic or repeat infections need more than a course of ear drops: the vet also has to find and manage the underlying trigger, or the infection returns.
When to see a vet vs. emergency red flags
You should see a vet for essentially any suspected ear infection, because the ear needs to be examined and swabbed before treatment. But certain signs are urgent. They can indicate the infection has moved from the outer ear into the middle or inner ear, which affects balance and the facial nerves and needs prompt care.
Can a dog ear infection spread to the brain?
It is uncommon, but a severe, deep, untreated ear infection can extend to nearby structures, and in rare cases inflammation can reach tissues near the brain. This is exactly why the neurological red flags above (head tilt, balance loss, facial drooping) are taken seriously and treated promptly.
There is no reliable way to predict how fast a serious infection will progress, so the safe answer is simple: do not wait on these signs, and let a vet assess the depth of the infection.
Do dogs act differently when they have an ear infection?
Yes. Ear pain can make a normally easygoing dog irritable, withdrawn, restless, or reluctant to be touched around the head. Some dogs eat less, sleep poorly, or seem grumpy. A sudden behavior or mood change alongside head shaking or ear odor is a meaningful clue, not just a bad mood.
How vets diagnose and treat a dog ear infection
A vet diagnoses an ear infection by examining the canal with an otoscope and running ear cytology to identify yeast, bacteria, or mites.
Treatment then targets what the swab shows: typically a thorough professional ear cleaning followed by medicated ear drops (which may combine an antibiotic or antifungal with an anti-inflammatory), and pain relief when needed.
The otoscope exam does more than confirm inflammation. It lets the vet check whether the eardrum is intact, which is critical because some cleaners and medications are unsafe if the eardrum is ruptured.
It also helps spot a foreign object like a grass awn, or a mass in the canal, that would change the plan entirely. For chronic, painful, or one-sided infections, the vet may recommend a bacterial culture, allergy testing, or imaging to find what keeps driving the problem.
There is no single “best antibiotic for a dog ear infection” and no universal dog ear infection medicine: the right drug depends on the organism identified. Some vets offer a longer-acting in-clinic gel that works like a one-time treatment for straightforward cases, but that decision is the vet's to make based on the exam.
Never use leftover drops from a previous infection or another pet.
For the full breakdown of medications, cleaning protocols, timelines, and follow-up rechecks, see our dedicated dog ear infection treatment guide.
A vet-strength medicated shampoo pairing 2% chlorhexidine and 2% miconazole, a potent antifungal and antibacterial combination widely used to help clear ringworm and yeast or bacterial skin infections. A premium bath option to cut fungal spore shedding as part of a vet-guided ringworm treatment plan.
Can I treat it at home, and what to avoid
You should not try to fully treat a suspected ear infection at home. An infected ear needs to be diagnosed first, because the wrong product, or cleaning a ruptured eardrum, can worsen the problem or damage hearing.
Home care is best limited to supportive steps your vet approves, such as keeping the ear dry and, in mild uncomplicated cases, using a vet-recommended cleanser.
If cost is the barrier, that is worth naming to your vet directly. Many clinics offer payment plans, and some areas have low-cost or nonprofit clinics. We cover safe, vet-informed supportive steps and the myths to avoid in our dog ear infection home remedies guide, but supportive care is not a substitute for a diagnosis.
For a complete overview of the condition, including the full range of types and outcomes, see our main dog ear infection pillar guide.
How to help prevent recurring ear infections
Preventing ear infections in dogs comes down to managing the underlying cause and keeping the ears clean and dry. Because allergies drive so many recurrent cases, working with your vet on allergy management is often the biggest lever. Alongside that, a few routine habits make a real difference.
- Dry the ears thoroughly after baths and swimming
- Clean the ears only as often as your vet recommends, using a vet-approved cleanser (over-cleaning irritates the canal)
- Check the ears weekly for early redness, odor, or debris
- Manage allergies with your vet's guidance (diet trials, medication, or environmental control)
- Keep up with recheck appointments so a lingering infection is fully cleared, not just quieted
One more prevention tip: monitor your dog's overall health for changes. If chronic ear issues appear alongside other symptoms such as increased thirst or urination, mention it to your vet, since a dog drinking and peeing a lot can point to an underlying condition worth checking during the same visit.
How long do dog ear infection symptoms last?
With proper treatment, a straightforward outer-ear infection often improves within a few days, and many cases resolve in one to two weeks. More stubborn or resistant infections can take longer and may need a follow-up swab to confirm the ear is fully clear.
The key point is that visible improvement is not the same as a cure: signs can quiet down while the infection is still present.
This is why finishing the full course of medication and keeping recheck appointments matter. Stopping early because the ear looks better is a common reason infections come roaring back, sometimes with a more resistant organism the second time around.
What happens if a dog ear infection goes untreated?
An untreated ear infection rarely just fades away. More often it becomes more painful and harder to clear. Over time, chronic inflammation can thicken and narrow the ear canal, which makes future infections more likely and more difficult to treat.
Persistent scratching and head shaking can also lead to a blood-filled swelling of the ear flap.
In more serious cases, an outer-ear infection can extend inward to the middle and inner ear, affecting balance and the facial nerves. Rarely, a deep infection can reach tissues near the brain. These outcomes are uncommon, and they are also exactly why catching symptoms early and treating them properly is worth it.
- 1Most treated outer-ear infections improve within days and resolve in one to two weeks.
- 2Signs quieting down does not mean the infection is cured: finish the full course and attend rechecks.
- 3Untreated infections tend to worsen, can thicken the ear canal, and in serious cases spread deeper.
Frequently asked questions
Frequently Asked Questions
How can I treat my dog's ear infection at home?
You should not try to fully treat a suspected ear infection at home, because it needs to be diagnosed first to know whether it is yeast, bacteria, or mites, and to confirm the eardrum is intact.
Safe home care is limited to vet-approved supportive steps like keeping the ear dry and using a cleanser your vet recommends. See a vet before using any medicated product.
Can a dog's ear infection go away?
A mild, early ear infection can sometimes settle down, but most infections do not reliably clear on their own and tend to worsen or recur without treatment. Because the underlying cause (often allergies or trapped moisture) usually remains, the infection commonly comes back. Proper diagnosis and treatment give the best chance of it fully resolving.
What to do if your dog has an ear infection but can't afford a vet?
Tell your vet about the cost concern directly, since many clinics offer payment plans or can prioritize the most essential steps. Look for low-cost, nonprofit, or veterinary school clinics in your area, and ask about charitable assistance programs. Avoid unproven home treatments that can worsen the infection and lead to bigger bills later.
Do dogs act up when they have an ear infection?
Yes. Ear pain can make a dog irritable, restless, withdrawn, or reluctant to be touched near the head, and some dogs eat or sleep less. A sudden change in mood or behavior alongside head shaking, scratching, or ear odor is a meaningful clue that the ear is bothering them.
Will hydrogen peroxide clear up a dog's ear infection?
No, and it can make things worse. Hydrogen peroxide can irritate and damage inflamed ear tissue, and it leaves moisture behind that actually encourages yeast and bacteria to grow. It is especially dangerous if the eardrum is ruptured. Use only products your veterinarian recommends.
How do I treat a dog's ear infection at home?
The safest approach is to have the ear examined and swabbed by a vet, then follow their treatment plan, which usually includes cleaning and medicated drops. At home, you can support recovery by keeping the ear dry, giving prescribed medications exactly as directed, and attending recheck visits.
Do not use hydrogen peroxide, alcohol, vinegar, or leftover medications.
What is the sock trick for ear infection?
The “sock trick” refers to a home remedy people mention for warming or comforting a painful ear, such as a warm compress. While a vet-approved warm compress may ease discomfort temporarily, it does not treat the infection itself.
It is not a cure, and a dog with an ear infection still needs veterinary diagnosis and treatment.
Can a dog ear infection cause vomiting?
It can, indirectly. When an infection reaches the inner ear, it disrupts balance and can trigger nausea, dizziness, and vomiting, much like severe motion sickness. Vomiting alongside a head tilt, stumbling, or rapid eye movements is a red flag for inner-ear involvement and warrants prompt veterinary care rather than waiting to see if it passes.
How fast can an ear infection kill a dog?
A routine outer-ear infection is not life-threatening, and most dogs recover fully with treatment. Deaths are very rare and would involve a severe, deep, neglected infection that spreads to tissues near the brain. There is no reliable timeline for that, and it is not something to gamble on.
The takeaway is not fear but action: treating symptoms early keeps a common, manageable problem from ever becoming a dangerous one.
Editor
The Webvet Editorial Team is the in-house group of pet-care editors and writers behind Webvet, operated by Smart Pet Collective. The team researches, writes, and maintains Webvet's pet health, behavior, and medication content. Every article follows a defined editorial process: research from reputable veterinary and scientific sources, careful drafting, mandatory review of medical content by a credentialed veterinarian, and dated publication. Health and medication articles are medically reviewed by a licensed veterinary professional before they go live and are kept current over time.
Veterinarian · BVMS MRCVS
Dr. Pippa Elliott, BVMS, MRCVS, is a veterinarian with nearly 30 years of experience in companion animal practice. Dr. Elliott earned her Bachelor of Veterinary Medicine and Surgery from the University of Glasgow. She was also designated a Member of the Royal College of Veterinary Surgeons. Married with 2 grown-up kids, Dr. Elliott has a naughty Puggle named Poggle, 3 cats and a bearded dragon.
