A few days ago I saw a patient called Otis. Otis had suddenly developed a swelling in one of his ear flaps (pinna). The swelling had developed very quickly. Otis’s dad was very concerned about the swelling as it was causing him some discomfort.

His main concern was ‘what’ is the swelling, ‘why’ does it happen and ‘how’ can we deal with it?

What is an aural haematoma?

The pinna (ear flaps) can be described as 2 layers of skin overlying a sheet of cartilage. A haematoma develops when blood vessels between the innermost skin layer and the cartilage leak and the blood pools between the 2 layers of tissue. Haematomas can develop in many parts of the body, think of a blood blister in people, often the haematoma may develop in an area where it may gradually absorb. The problem with haematomas in ears is that resorption of the blood is fairly slow and the haematoma can make the ear feel a little uncomfortable, leading to increased head shaking, which may lead to further blood vessel trauma and leakage. Hence healing can be very slow.

Why do haematomas form?

Haematomas may form after any trauma to the ears.

The most common reason we identify for haematoma formation in ears is when dogs shake their heads due to ear infections and skin disease. Less common reasons may be due to a fight with another dog, due to flea infestation or ear mites, or due to issues with blood clotting such as rodenticide (ratbait) ingestion.

How can we deal with it?

Put simply to heal a haematoma we need to empty the blood from between the layers of tissue and treat or manage any underlying conditions.

If we do nothing it is possible some haematomas, especially small ones, will gradually reduce by themselves. Often the ear will end up mis-shapen- developing into a ”cauliflower ear”.

It is tempting to simply drain the haematoma using a needle, or even by making a small incision into the sac to allow it to drain, but often they will reform over a few hours to days after draining.

Treatment is more successful if a technique is used to keep the sack that the fluid had pooled in deflated until the tissues have time to re-adhere together.

Traditionally this involves a general anaesthetic, the sack is incised and the fluid drained out then the 3 layers of the ear are sewn together with an absorbent pad, buttons or even xray film as a support for the tissue. Sutures are usually left in for 2-3 weeks

An alternative approach may be to insert a small needle or drain in through a tiny incision in the sack, and then attaching a closed suction system for a period of several days to the drain or needle. This technique is certainly less traumatic but it can be difficult to maintain the closed suction system.

Of course, as mentioned above it is important to treat any underlying cause such as ear infections or fleas.