Moderate severity
Aural Haematoma (Ear Flap Blood Blister)
A swollen, fluid-filled ear flap caused by burst blood vessels, usually after violent head-shaking or scratching at an itchy, infected or mite-ridden ear.
⚠️ Common symptoms
An aural haematoma is one of the more dramatic-looking ear problems in cats: an ear flap that seems to inflate almost overnight into a soft, squashy cushion. It happens when small blood vessels inside the pinna break and leak, filling the space between the skin and the ear cartilage with blood and serum. Though the swelling itself is the obvious sign, it is really a symptom of something else going on in the ear.
The chain of events almost always begins with an itchy or sore ear. Ear mites, a bacterial or yeast infection, an allergy or a trapped grass seed set off intense head-shaking and scratching, and the repeated whipping and battering of the ear flap is enough to tear its delicate blood vessels. This is why treating an aural haematoma is a two-part job: relieving and draining the swelling, and just as importantly identifying and clearing the underlying ear disease so the shaking stops and the problem does not simply recur.
Untreated, a haematoma will eventually resolve on its own as the body reabsorbs the blood, but the healing ear tends to contract and pucker into a thickened, crinkled shape — the feline version of a "cauliflower ear". Veterinary treatment, whether draining with a drain in place or a small surgical repair that stitches the ear flat while it heals, gives a far better cosmetic and comfort outcome. The take-home message for owners is not to ignore a cat that has started shaking its head or worrying at an ear: catching and treating the cause early can prevent the haematoma forming at all.
🔍 Causes
An aural haematoma forms when blood vessels within the ear flap rupture and blood pools between the skin and cartilage. The usual trigger is vigorous, repeated head-shaking or scratching, which is itself a response to an itchy or painful ear — commonly ear mites, a yeast or bacterial ear infection, allergies, or a foreign body such as a grass seed. Trauma from a fight or knock can also cause one.
🛡 Prevention
Because the swelling is almost always driven by an itchy ear, prevention means treating ear problems early. Check your cat’s ears regularly for dark wax, odour or redness, keep up parasite control against ear mites, and see a vet promptly at the first sign of persistent head-shaking or scratching rather than waiting for the ear to balloon.
💊 Treatment
Treatment aims both to drain the swelling and to fix whatever caused the head-shaking. A vet may drain the blood with a needle, though it often refills, so many cases are managed with a small surgical drain or an operation to open, clear and quilt the ear flap so it heals flat. Anti-inflammatories and treatment of the underlying ear infection, mites or allergy are given alongside. Left alone, the blood is slowly reabsorbed but the ear frequently scars into a permanently puckered shape.
⚕️ Medical disclaimer
- This information is educational only and is not a substitute for veterinary advice.
- Symptoms overlap between conditions — only a vet can diagnose accurately.
- Never withhold treatment or self-medicate based on information found online.
- When in doubt, call your vet. Early intervention almost always leads to better outcomes.