Dog Ear Infections: Head-Shaking, Odor, and What Actually Helps
Head-shaking, scratching, a strong smell, and dark discharge are the classic signs of a dog ear infection. This guide explains what causes them, why floppy-eared and allergic dogs get them repeatedly, how vets treat them, and how to prevent the frustrating cycle of recurrence.
Quick answer
Head-shaking, ear-scratching, redness, an unpleasant smell, and brown or yellow discharge usually mean an ear infection. These need a vet, not just home cleaning, because the right treatment depends on whether bacteria, yeast, or ear mites are involved — and on ruling out a ruptured eardrum before any medication goes in. Most cases clear well once treated correctly.
Head-shaking, scratching, a strong smell, and dark discharge are the classic signs of a dog ear infection.
How to recognise an ear infection
Dogs with ear infections often shake their head, tilt it to one side, scratch or rub the ear on furniture, and flinch when the ear is touched. Look inside: healthy ears are pale pink and nearly odourless, while an infected ear is red, swollen, warm, and smells yeasty or foul. You may see brown, waxy, or yellow discharge. Some dogs go quiet or off their food because the pain is real.
Lift the ear flap in good light and look for redness, discharge, or a yeasty smell.
Why dogs get ear infections
A dog's ear canal is long and L-shaped, so moisture and debris get trapped easily. The most common triggers are allergies (to food or environmental pollens), moisture from swimming or bathing, and, in humid climates, the general warmth and dampness that let yeast and bacteria thrive. Floppy-eared breeds such as Cocker Spaniels and dogs with hairy canals are especially prone. Ear mites are a common cause in puppies but less so in adults.
Why it keeps coming back
Recurrent ear infections are one of the most frustrating problems for owners, and the reason is almost always an underlying cause that has not been addressed — most often allergies. If the infection is treated but the allergy isn't managed, it returns. Chronic, repeated infections can thicken and narrow the canal over time, making them harder to treat, which is why getting to the root cause early matters.
After applying a vet-approved cleaner, massage the ear base for a few seconds, then let your dog shake.
What actually helps
Proper treatment starts with a vet examining the ear, often with an otoscope, and looking at a swab under the microscope to identify yeast, bacteria, or mites. This determines which medicated ear drops are needed. Your vet will also check the eardrum is intact, because some cleaners and drugs can cause harm if it is ruptured. Finish the full course even if the ear looks better quickly, and go back for the recheck.
Preventing the next one
After swimming or bathing, dry the ears gently and, if your vet advises, use a vet-approved drying cleaner. Keep hairy canals trimmed if your groomer recommends it. Most importantly, if infections keep returning, ask your vet to investigate allergies — controlling the underlying allergy is what finally breaks the cycle. Routine cleaning of healthy ears is not needed and can cause irritation if overdone.
Quick FAQs
Can I treat a dog ear infection at home? Not on your own. You need a vet to identify the cause and confirm the eardrum is intact before medication. Home cleaning alone rarely clears a true infection.
Why does my dog's ear smell so bad? A strong yeasty or foul smell is a hallmark of infection, usually from an overgrowth of yeast or bacteria in the warm, moist canal.
Are some breeds more prone? Yes — floppy-eared breeds and dogs with hairy or narrow canals, plus any dog with allergies, get ear infections far more often.
How long until it clears up? With the right medicated drops most cases improve within a week or two, but always finish the course and attend the recheck to confirm it has fully resolved.