About: An ear hematoma is a localised pocket of blood due to a ruptured blood vessel.
Causes: The most common cause is trauma from scratching due to ear mites. Other causes include head shaking or a blow to the ear.
Symptoms: Painful swelling of the ear, which will feel warm.
Treatment: Needle aspiration to drain the blood, or surgery to remove the blood and staple the affected area.
What is an ear hematoma?
An ear hematoma (aural hematoma) is a localised pocket of blood which has formed due to the rupture of a blood vessel within the ear.
The ear flap is composed of three layers.
Cartilage plate: The innermost layer of the ear which provides the shape and rigidity.
Perichondrium: A layer of connective tissue which provides the blood supply to the cartilage.
Skin: The outer layer of the ear. On the outermost layer is the skin which is covered with short hairs on the outside.
When a blood vessel ruptures, blood becomes trapped between the perichondrium and the underlying cartilage.
Trauma to the skin which leads to the rupture of blood vessels is the underlying cause which may be due to scratching, blunt force 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 anear mite infection. Other causes of ear hematoma may include:
Otitis externa (infection of the ear canal)
Foreign object such as grass awn
Trauma, such as a knock to the ear
Head shaking, although this is more common in dogs
Ear hematomas are extremely painful and require prompt veterinary attention.
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.
Your veterinarian will 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.
Fine needle aspirate: This test 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.
Cytology: This test will help the veterinarian determine if there is an underlying cause, such as an ear infection or parasites. A sample of exudate from the ears will be examined under a microscope to look for mites or bacteria.
Punch biopsy technique: The simplest method is to use a skin biopsy punch 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.
Surgical technique (incision and drainage): Larger hematomas require surgical treatment. Typically this involves making either a straight or an S shaped 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?
The image above is a rescue cat who has clearly had an ear hematoma at some point in her past. Note the flattened and distorted appearance to her ear.
Ear hematomas are extremely painful, do not attempt to rupture one at home. Surgery must be performed under sedation, in a sterile environment to reduce the chance of introducing bacteria to the site. 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, which can lead to 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 highlights the importance of veterinary attention if your cat develops an ear hematoma.