What is an aural hematoma?
A hematoma is a localized mass of blood that is 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 an 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, resulting in bleeding 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 piece of grass. It is also possible that a foreign body initiated the shaking 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 an 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:
1. The blood is removed from the pinna. This is accomplished by making a small incision at each end of the hematoma. A drain tube may be passed through the hematoma and sutured to the ear to remove any more blood or serum that accumulates in the area. Alternatively, the skin over the hematoma may be incised and opened completely.
2. The space where the blood accumulated is eliminated. This is accomplished by placing a series of sutures (stitches) that are passed completely through the ear flap holding both layers of skin to the cartilage.
3. The pinna is stabilized to prevent further damage. It may be supported by a bandage or other material applied directly to the ear, or by bandaging the ear against the head. Shaking after the ear pinna has been sutured at this time may cause further damage to the ear.
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?
Drainage tubes or bandages may be removed by your veterinarian after 3–14 days. There may be one or more drainage holes from the drain or incision, which will be left to heal by scar tissue. The sutures may be removed after two weeks if the ear is completely healed; in severe cases, some or all of the sutures may be left in place for up to two weeks longer.
If discharge from the surgery sites occurs before they close, it should be cleaned off with mild cleansing soap. If an infection was present, it will be necessary to recheck 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, the hematoma may slowly be reabsorbed, but the associated inflammation will cause damage to 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, for an affected cat’s welfare, should be treated promptly.
Can the swelling simply be drained?
Drainage may result in a temporary correction but, in the majority of cases, the hematoma will return within one to two days. Drainage may be used if the hematoma is very small, or if the patient cannot undergo surgery for some reason. If drainage is the chosen treatment, be prepared to return to your vet for a few visits, as repeated draining is often necessary. This treatment method may eventually eliminate the problem, although it will take longer to achieve the same result as surgery. Anti-inflammatory medication is usually prescribed in these cases.
