Hematoma simply means “blood filled mass”. A hematoma of the ear flap (pinna) is caused by a ruptured vessel leaking blood between the layers of skin covering the inner and outer external portion of the ear. Because the blood cannot escape the body, the ear pinna fills like a pillow or balloon. Dogs and cats can be diagnosed with an aural hematoma. Canine hematomas are usually associated with an ear infection. The pain and irritation causes the dog to shake its head violently, causing a whipping effect of the ear flap. The increased blood pressure in the vessels causes them to rupture. Another cause of a hematoma can be a trauma such as from fight wounds, and this is the more common cause of hematomas in cats. The shorter the ear pinna, the less likely that a whipping action caused the blood vessels to rupture. In any case, an ear infection should be ruled out as an underlying reason for a hematoma.
Surgical repair is usually recommended for aural hematomas. Aspirating the blood with a needle and syringe can deflate the pinna, but this treatment is seldom effective. The hematoma will probably recur, and infection can occur if the hematoma is contaminated. Left untreated, the blood will reabsorb and form scar tissue, causing the ear pinna to shrink and deform. This is sometimes called a cauliflower effect, and can occlude the ear canal leading to increased risk of ear infections.
The window of opportunity to surgically repair an aural hematoma is typically within a week of its occurrence. The pet is administered a general anesthetic after pre-surgical blood work confirms that there are no contraindications precluding surgery. If an ear infection exists, the ear canal may be swabbed to send samples to a reference laboratory for culture and susceptibility testing. This can greatly expedite a successful resolution of the infection. Also, the ear canal may be flushed with antiseptic during anesthesia to facilitate a thorough cleaning before beginning topical treatments at home.
The ear pinna is shaved and prepped before an incision is made through one layer of skin over the length of the hematoma. The blood is drained, and the blood clots that would otherwise form scar tissue are removed. There are variations in technique at this point, but all achieve the same purpose. The Variation would be to tack the two sides of the ear pinna together leaving an opening to drain any residual bleeding that may occur. This will cause the two sides of the ear to scar together so that there will be no “pocket” to fill up with blood in the future. Some veterinarians will suture a piece of plastic to the back of the ear to help hold the pinna straight while healing. Local anesthetic may be infused into the pinna to help with pain control.
An Elizabethan collar is worn during healing to prevent the pet from scratching at the sutures, and sutures are removed after 14 to 21 days. Healing times are generally longer than spay or neuter surgery to ensure that the hematoma does not recur. Oral antibiotics and pain medications are sent home after surgery. Antibacterial / antifungal ear ointments are dispensed in the case of an ear infection.