What is an ear hematoma?
An ear hematoma (also known as aural hematoma) is a localised pocket of blood which has formed due to the rupture of a blood vessel within the ear. When this occurs, blood becomes trapped between the periochondrium and the underlying cartilage.
The ear flap is composed of three layers.
- Cartilage plate which provides the shape and rigidity of the cat's ear. The cartilage is the the innermost layer of the pinnae.
- Perichondrium, a layer of connective tissue which provides the blood supply to the cartilage.
- On the outermost layer is the skin which is covered with short hairs on the outside.
What causes an ear hematoma?
Trauma, which leads to the rupture of blood vessels is the underlying cause which may be due to scratching or head shaking. The skin and fur on the ears is extremely thin, making the underlying blood vessels more vulnerable to damage than on other areas of the body protected by a thicker layer of fur and skin. Once a blood vessel breaks, blood leaks into the surrounding tissue.
- The most common cause of scratching is due to an ear mite infection which damages the skin and blood vessels below causing them to burst. Other causes of itching include otitis externa (infection of the ear canal), ticks, fleas, cat fights, foreign object such as grass awn and allergies.
- Head shaking, although this occurs in dogs more than cats.
- Trauma, such as a knock to the ear.
Ear hematomas are extremely painful and require prompt veterinary attention.
What are the symptoms of ear hematoma in cats?
The most obvious symptom of an ear hematoma is swelling of the ear. This may be partial or the entire ear may become swollen and filled with blood. The ear will feel soft, warm and fluid filled.
How is an ear hematoma diagnosed?
Your veterinarian should be able to diagnose an ear hematoma based on appearance, however, as tumours and abscess can also have similar symptoms to ear hematomas your veterinarian may need to differentiate between these conditions. He may perform a fine needle aspirate, which involves drawing out some of the fluid from the ear and analyzing it under a microscope. If it contains blood, this will confirm an ear hematoma.
He will also need to determine what caused the hematoma, for example, does the cat have an ear infection, parasites etc?
What is the treatment for an ear hematoma?
- Needle aspiration: The simplest method is to use a needle to remove the fluid from the ear and then flush the ear with saline to clear any blood clots. Cortisone may then be injected into the ear. This method is best for small hematomas only. This method isn't always effective and it is very common for the hematoma to return within a day or so.
- Incision and drainage: Larger hematomas require surgical treatment. Typically this involves making an incision and draining the fluid and blood clots from the ear. The incision will either be left partially open to allow for drainage of any fluids that may continue to leak or he may place a drain in the ear. He may either place multiple sutures in the ear and or bandage the ear to prevent further damage, allow the underlying tissues to re-adhere and avoid the hematoma recurring. Your cat will be given pain relief for the first 24-48 hours after surgery. An Elizabethan collar may be necessary to prevent your cat from scratching the ear as it heals. The sutures and bandages will need to be removed 2-3 weeks after surgery.
Finding and treating the underlying cause of the itching/scratching that leads to the hematoma will also be necessary. This may include eliminating parasites, treating infections with daily ear cleaning as well as antibiotics and finding/eliminating allergies.
Can I treat an ear hematoma at home or just wait for the hematoma to be reabsorbed?
Do not attempt to burst an ear hematoma at home. An ear hematoma is extremely painful, and this surgery should be performed under sedation, in a sterile environment. Trying to handle a cat who is already in pain is going to be stressful to the cat and there is a high probability you will be injured in the process. The skin acts as a protective barrier between the outside world and the inner body, any time you lance or pierce the skin, you introduce bacteria, resulting in an infection or abscess.
Waiting for the body to reabsorb the blood can take weeks, and as ear hematomas are so painful, it prolongs the suffering of your cat. Also, as the perichondrium has separated from the underlying cartilage, it is no longer receiving a blood supply, which can cause it to die. When this occurs, fibrous tissue develops over the tissue causing disfigurement known as 'cauliflower ear'. This is why it is extremely important to seek veterinary attention if your cat develops an ear hematoma.