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.
The ear flap is composed of a layer of skin on each side of a layer of cartilage. The cartilage gives the ear flap its shape. Blood vessels go from one side to the other by passing through the cartilage. Violent shaking causes the vessels to break as the skin slides across the cartilage.
Ear hematomas occur when a blood vessel in the ear bursts and bleeds into the space between the ear cartilage and skin. This is most commonly associated with trauma such as scratching or shaking the ears and bite wounds. Dogs with ear infections may violently shake their head or scratch their ears causing an aural hematoma. Dogs with long, floppy ears are at greater risk for developing ear hematomas. Pets with clotting or bleeding disorders may also develop hematomas, with or without a history of trauma.
What is the treatment?
There are two approaches used to treat aural hematomas. The first is the conservative approach. A needle is used to withdraw the fluid from within the pinna. An injection of a corticosteroid may be made into the area that contained the fluid. The pinna is bandaged so that pressure is applied to it to prevent recollection of fluid. This method is used when the hematoma is small or if financial limitations prevent surgery. However, the success rate is less than 50%.
Because the success rate is so low with conservative treatment, most ear hematomas are treated with surgery. If surgery is chosen, there are four commonly used steps. However, different situations require different surgical techniques.
The blood is removed from the pinna. This is accomplished by making a small incision in each end of the hematoma. A drain tube is passed through the hematoma and sutured to the ear. This assures drainage of any more blood or serum that accumulates in the area. Alternatively, the skin over the hematoma may be incised and opened completely. This is more likely to be used for more serious hematomas and for those in which the blood has clotted.
The space where the blood accumulated is obliterated. Since the skin over the hematoma has been pushed away from the cartilage, it must be reattached to it to prevent another hematoma from occurring. This is accomplished by a series of sutures that are passed completely through the ear flap.
The pinna is stabilized to prevent further damage. Shaking after the ear pinna has been sutured at this time may cause further damage to the ear. In some cases, the pinna is laid on top of the pet's head and bandaged in place. Although the bandage may be somewhat cumbersome, it will prevent further damage to the pinna and allow proper healing to progress.
The cause of the problem is diagnosed and treated. Another important aspect of treatment is dealing with the cause of the shaking. If an infection is present, medication is prescribed to treat the problem. In some cases, there is a piece of foreign material lodged in the ear canal such as a tick, piece of grass, etc., which is removed. It is also possible that a foreign body initiated the shaking but was later dislodged. If that occurs, and no infection is present, further treatment of the ear canal is not needed.
What follow-up treatment is needed?
Any sutures, drainage tubes or bandages are generally removed in about three to fourteen days. At that time, the hematoma is usually healed. In severe cases, some or all of the sutures will be left in place for up to two weeks longer. There will be one to two holes or slits in the skin where the surgery or drain tube was placed. This will close within a few days. If discharge occurs from the surgery sites before they close, it should be cleaned off with mild cleansing soap or hydrogen peroxide.
If an infection was present, it will be necessary to recheck the ear canal to be sure that the infection is gone. Otherwise, another hematoma may occur.
Hematomas have a recurrence rate of approximately 30%. Report any future swellings or ear abnormalities to your veterinarian at once.