Aural Haematoma in Dogs

What is a haematoma?

It is a localised collection of blood, usually clotted and can occur anywhere in the body. Bruises can be considered a form of haematoma. In the dog the most common type of haematoma is that affecting the flap of the ear (pinna). At this site it can be thought of as a blood blister.

Why do aural haematomas occur?

Irritation and infection of the ear canal is very common particularly in dogs with dropped ears, e.g. Spaniels, Bassets, etc. If the ear canal is itchy, the dog scratches and sometimes will shake the head violently. This can cause damage to the delicate blood vessels in the ear flap which results in bleeding and thus the formation of a “blood blister” (haematoma). Depending on severity and length of time present this can involve just part of the ear flap or the whole pinna can be involved. The swelling increasingly bothers the dog and flapping, shaking and scratching increase, thus making the situation worse.

What can be done?

The underlying cause has to be accurately diagnosed and treated. In the majority of cases it involves infection within the ear canal. This causes irritation resulting in head shaking and scratching leading to damage to the blood vessels which lie between the cartilage and the skin on both sides of the pinna. The swelling must also be treated and this can be done in various ways:-

• Aspiration, which is drainage by sucking out the fluid using a needle and syringe. Often a small quantity of a corticosteroid preparation and/or antibiotic is then injected into the site. With small swellings this is often all that is needed provided the reason for the irritation has been successfully treated.
• Treatment of choice, certainly with larger haematomas involves surgical drainage and prevention of recurrence of the swelling. Various techniques are available to achieve this, usually involving either the insertion of drainage tubes or multiple sutures to ensure that the space between the cartilage and overlying skin is reduced as much as possible. These sutures usually have to be left in for two or three weeks and sometimes the head or ear bandaged while healing occurs.

If it is a blood blister, won’t it disappear with time, just like a bruise?

Theoretically this is possible but the discomfort of the swelling encourages the dog to continue shaking and scratching even if the original infection has been effectively treated. This can lead to further bleeding thus increasing the size of the haematoma. 

Can you not just keep draining the swelling?

This is possible but unfortunately draining just removes fluid and without surgery we cannot remove the clots. Left in situ, these clots contract and form fibrous tissue which results in distortion of the ear. Once this stage has been reached the situation is often irreversible.