Dog Ear Infections: Causes, Signs and Treatment

Ear infections are one of the most common reasons dogs end up at the vet — and one of the most uncomfortable problems for them. If your dog is shaking their head, scratching at an ear, or there's an unpleasant smell coming from it, this guide will help you understand what's happening and what to do.

This is general guidance, not a substitute for veterinary advice — if you're worried about your dog, contact your vet.

What an ear infection is

An ear infection, which vets call otitis, is inflammation of the ear canal, usually involving an overgrowth of the bacteria or yeast that normally live in small numbers on the skin. A dog's ear canal is long and L-shaped — very different from ours — which traps moisture, warmth and debris and creates perfect conditions for infection to take hold. Most infections affect the outer ear canal, but if they're left untreated they can spread deeper, which is why early treatment matters.

Common causes

Here's the important bit: an ear infection is often a symptom of something else, which is why they keep coming back if the underlying cause isn't addressed. Common triggers include:

• Allergies — one of the biggest culprits. Dogs with skin or food allergies very commonly get repeated ear infections.
• Moisture — water trapped after swimming or bathing.
• Ear mites — more common in puppies.
• Excess hair or wax — which traps debris in the canal.
• Foreign objects — grass seeds are a classic summer problem in the UK.
• Ear shape — breeds with floppy, hairy ears such as spaniels, retrievers and poodles are more prone, as the ear flap reduces airflow.

Signs and symptoms

Look out for:

• Head shaking, or tilting the head to one side.
• Scratching or rubbing the ear, sometimes against furniture or the floor.
• Redness, swelling or heat in the ear.
• A bad smell, or a brown, yellow or waxy discharge.
• Pain when you touch the ear, whining, or reluctance to be touched there.
• In ongoing cases, a thickened, leathery ear canal.

What you can do at home

Ear infections almost always need veterinary treatment, but you can support healthy ears and prevent some problems:

• Check your dog's ears regularly so you catch problems early — a quick look and sniff once a week is ideal.
• Dry the ears gently after swimming or bathing.
• Use only a vet-recommended ear cleaner, and never poke cotton buds down the canal — you can cause damage or push debris deeper. You'll find suitable ear cleaners in our shop.
• Keep ear hair tidy on hairy-eared breeds, following your groomer's or vet's advice.
• Don't use leftover medication from a previous infection without checking with your vet, as the wrong product can make things worse.

Because allergies drive so many ear infections, our dog allergies and dog itchy skin guides are well worth reading if your dog gets repeated ear trouble.

Why ear infections keep coming back

One of the most disheartening things for owners is an ear that clears up with treatment, then flares again a few weeks later. When this happens, it almost always means the original infection was a symptom of an underlying cause that hasn't been tackled — most often allergies, but sometimes ear shape, excess hair, or a foreign body that was never fully resolved. Treating the infection alone is a bit like mopping the floor while the tap is still running. The way to break the cycle is to work with your vet to identify and manage that root cause, which might mean allergy management, a change in grooming routine, or regular preventive ear care. It can take some detective work, but getting to the bottom of it spares your dog a lot of repeated discomfort and you a lot of repeat vet trips. It's also why finishing the full course of any prescribed drops matters, even once the ear looks better — stopping early lets the infection rebound.

When to see a vet

See your vet if your dog shows any signs of an ear infection — they need to look inside the ear with the right equipment, identify the cause, and prescribe the correct treatment. Seek prompt help if:

• Your dog is in obvious pain or the ear is very swollen.
• There's a sudden head tilt, loss of balance, walking in circles, or unusual eye movements (this can mean the deeper ear is affected and needs urgent attention).
• Infections keep coming back despite treatment — that usually means an underlying cause, often allergies, needs investigating.

Untreated ear infections can become very painful and lead to lasting damage to hearing and the ear canal, so don't try to wait it out. Find a vet near you via our vets directory, and the pet medicine calendar helps you finish the full course of any prescribed ear drops, which is important even once the ear looks better.

Sources

• PDSA — Pet Health Advice
• Blue Cross — Pet Advice
• RSPCA — Dogs