Condition guide·🐶 Dogs· 7 min

Aural Hematoma in Dogs: The Swollen Ear Flap Explained

By Marwan Samir·Updated September 14, 2026

The short answer

An aural hematoma is blood collecting inside the ear flap, usually caused by head shaking from an underlying ear problem. The flap becomes thick and spongy. It is painful and needs prompt treatment — untreated, it can heal into a permanently distorted, cauliflower-shaped ear.

What it is

An aural hematoma is a collection of blood — fresh or clotted — within the pinna, the ear flap. Veterinary sources describe the affected pinna as appearing very thick and spongy. The swelling may involve the whole flap or only one area of it.

The mechanism is mechanical. Excessive or violent head shaking causes one or more blood vessels to break, and blood leaks into the space between the ear cartilage and the skin on the inner surface of the ear.

The cause behind the cause

This is the part that matters most, and it is the reason treating the swelling alone fails.

Most dogs that develop an aural hematoma have an underlying problem driving the shaking — an ear infection, an allergy, a bite wound, or another inflammatory ear condition causing excessive scratching and head shaking.

So the hematoma is a consequence, not a diagnosis. Draining it without identifying and treating what caused the shaking means the dog keeps shaking and the hematoma refills. The productive question at the appointment is what is making the ear itch or hurt.

What you will see and feel

A soft, fluid-filled, spongy swelling of the ear flap, often described as feeling like a water balloon.
Thickening of part or all of the pinna.
Warmth and obvious tenderness — these are painful.
Head shaking, scratching at the ear, or holding the head tilted toward the affected side.
Often the signs of the underlying ear problem too: redness, discharge, a yeasty or sour smell.

Why it should not be left

Untreated has a permanent cost

Aural hematomas are very painful and should be treated promptly. If left alone, the blood may slowly reabsorb — but the associated inflammation damages the surrounding ear tissues, and the flap can heal into a distorted, cauliflower-shaped ear. That scarring can be severe enough to obstruct the ear canal, which in turn makes future ear infections more likely and harder to treat. The cosmetic result is the least of it.

What treatment involves

Described so you know what to expect, not as something to attempt at home. There are two broad approaches and the choice depends on the case.

The surgical approach places a series of sutures completely through the ear flap, holding both layers of skin against the cartilage. That stabilises the pinna, prevents the space refilling, and prevents further damage as it heals.

The non-surgical approach drains the hematoma and injects a steroid into the pocket. Repeated draining is often needed, so expect several visits, and oral steroids are frequently prescribed alongside. It can eventually resolve the problem but generally takes longer to reach the same result as surgery.

In either case, the underlying ear condition is treated at the same time — otherwise the shaking continues and so does the problem.

Do not drain it yourself, and do not put anything in the ear first

Draining at home risks introducing infection into a closed blood-filled space, and it will refill regardless because the cause is still there. Equally important: do not reach for ear cleaner or leftover ear medication before a vet has looked down the canal with an otoscope. If the eardrum has ruptured — which happens with untreated infections — some cleaners and medications can reach the middle ear and cause serious damage including hearing loss and balance problems.

Preventing the next one

Prevention is really prevention of the head shaking, which means managing the underlying ear disease properly.

Ear infections in dogs are usually secondary, most often to allergic skin disease. A dog on its third course of ear treatment in a year does not have three separate infections — it has one unaddressed cause. Identifying that is what stops the cycle, and it is the difference between managing episodes and resolving the problem.

See a vet for

Any soft swelling developing in the ear flap, with or without the other signs — the sooner it is treated the better the cosmetic and functional outcome. Also for head shaking lasting more than a day, ear discharge, redness, smell, or pain when the ear is touched. Seek prompt care if head shaking comes with loss of balance, circling, falling or rapid flicking eye movements, which suggests middle or inner ear involvement and needs different treatment.

Frequently asked

What is an aural hematoma in dogs?

A collection of blood inside the ear flap. Violent head shaking breaks blood vessels and blood leaks into the space between the ear cartilage and the skin, making the flap thick and spongy — often described as feeling like a water balloon.

What causes an aural hematoma?

Head shaking, and behind that an underlying ear problem. Most affected dogs have an ear infection, an allergy, a bite wound or another inflammatory ear condition causing excessive scratching and shaking. The hematoma is a consequence, not the diagnosis.

What happens if an aural hematoma is left untreated?

The blood may slowly reabsorb, but the inflammation damages surrounding tissue and the flap can heal into a distorted, cauliflower-shaped ear. That scarring can obstruct the ear canal, which makes future infections more likely and harder to treat.

How is an aural hematoma treated?

Either surgically — sutures placed through the flap holding the skin against the cartilage so the space cannot refill — or non-surgically by draining and injecting a steroid, which usually needs repeating over several visits. The underlying ear condition is treated at the same time.

Can I drain it at home?

No. Draining at home risks introducing infection into a closed blood-filled space, and it will refill because the cause is still present. Also do not put ear cleaner or leftover medication in the ear before an otoscope exam — a ruptured eardrum makes some products capable of causing hearing loss.

How do I stop it happening again?

By stopping the head shaking, which means treating the underlying ear disease properly. Ear infections in dogs are usually secondary, most often to allergic skin disease — repeated treatment courses in one year mean one unaddressed cause rather than several infections.

Sources

Every claim on this page is checked against published veterinary sources. Here is where it comes from.

1Hematoma of the Ear in Dogs — VCA Animal Hospitals
2Ear Hematoma in Dogs: Signs, Symptoms, and Treatments — American Kennel Club
3Ear Infections in Dogs (Otitis Externa) — VCA Animal Hospitals

This page explains a veterinary condition in plain English so you can recognise it and have a better conversation with your vet. It is written from published veterinary sources, cited below, by someone who is not a veterinarian. It cannot diagnose your animal, and it deliberately contains no dosing or treatment instructions.