What is an aural hematoma?
A hematoma is a localized mass of blood confined within an organ or tissue. An aural hematoma is a collection of blood, either fresh or clotted, within the pinna (ear flap). When a hematoma is present, the pinna will appear very thick and spongy. The swelling may involve the entire pinna or it may involve only one area of the ear.
What causes aural hematoma?
The external ear has a layer of skin on both sides and a layer of cartilage sandwiched between the two skin layers. Blood vessels run just beneath the skin. When something irritates the ear canal, your cat will respond by scratching or shaking its head. Excessive or violent shaking causes one or more blood vessels to break, causing blood to leak into the space between the ear cartilage and skin on the inner surface of the ear.
Most cats that develop an aural hematoma have an infection, allergy, or other inflammatory ear condition that causes excessive scratching and head shaking. In some cases, there may be a piece of foreign material lodged in the ear canal, such as a tick or a piece of grass. In other cases, a foreign body may have caused the initial irritation but was later dislodged. Cats with a bleeding or clotting disorder may also develop an aural hematoma with or without a history of trauma.
What is the treatment for aural hematoma?
Many aural hematomas are treated with surgery. The actual surgical technique varies with the individual circumstances and veterinarian's preference but always involves these basic steps:
- Remove the blood from the pinna. Your veterinarian will make a small incision at each end of the hematoma. They may pass a drain tube through the hematoma and suture it to the ear to remove any more blood or serum that accumulates in the area. Alternatively, they may cut the skin over the hematoma and open it completely.
- Eliminate the space where blood accumulated. Your veterinarian will place a series of sutures (stitches) completely through the ear flap, holding both layers of skin to the cartilage.
- Stabilize the pinna to prevent further damage. If the dog shakes after the ear pinna is sutured, it may cause further damage to the ear. Your veterinarian will apply a bandage or other material directly to the ear to support the pinna, or they may bandage the ear against the head.
Some aural hematomas are treated by draining the hematoma and injecting a steroid into the pocket. Repeated draining is often needed, so be prepared to return to your veterinarian for a few visits. Oral steroids are often recommended as well. This treatment method may eventually eliminate the problem, although it may take longer to achieve the same result as surgery.
Some hematomas are treated with oral steroids alone, depending on their size and location. Repeating draining of the hematoma is sometimes required. If an underlying cause is found, such as an infection, allergy, or foreign body, it will be treated once the hematoma is corrected.
What follow-up treatment is needed?
Your veterinarian may remove drainage tubes or bandages after 3 to 14 days. In some cases, there may be one or more drainage holes from the drain or incision, which will be left to heal naturally. The sutures (stitches) may be removed after two weeks if the ear is completely healed; in severe cases, some or all the sutures may be left for up to two weeks longer.
If there is discharge from the surgery sites before they close, clean it off with mild soap. If an infection is present, your veterinarian may prescribe medication and will recommend a recheck of the ear canal to be sure the infection has resolved. Otherwise, another hematoma may occur.
What if an aural hematoma is left untreated?
If left untreated, an aural hematoma may be slowly reabsorbed, but the associated inflammation will damage the surrounding ear tissues, resulting in a distorted, cauliflower-shaped ear that could obstruct the ear canal. The longer the hematoma is left untreated, the greater the likelihood of permanent damage and disfigurement. Aural hematomas are very painful and should be treated promptly.
