An aural (ear) hematoma is a collection of blood, serum, or a blood clot within the pinna (ear flap). When present, the pinna will be very thick. The swelling may involve the entire pinna or it may involve only one area.
How is it caused?
When something irritates the ear canal, the cat responds by scratching or shaking its head. Excessive shaking causes blood vessels to break, resulting in bleeding. An understanding of the ear's anatomy makes the sequence of events more logical.
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 side-to-side by passing through the cartilage. Violent shaking causes the vessels to break as the skin slides across the cartilage.
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, and an injection of a corticosteroid is 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 only about 50%.
If surgery is chosen, there are four commonly used steps. However, different situations call for variations.
- 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 large 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 through the ear flap.
- The pinna is stabilized to prevent further damage. The presence of the drain tube will cause the cat to shake its head even more. Shaking at this time may cause further damage to the pinna. Therefore, the pinna is laid on top of the cat'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 dispensed to treat it. However, some cats have no infection but have foreign material (a tick, piece of grass, etc.) lodged in the ear canal. If so, the foreign material 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?
The drain tube and bandage are generally removed in about 3-5 days. At that time, the hematoma is usually healed. There will be two holes in the skin where the drain tube entered. They will close within a few days. If discharge occurs from the holes before they close, it should be cleaned off with hydrogen peroxide. In some cats, the stitches through the ear flap will be removed, and in others, they dissolve.
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.