Aural hematomas in dogs
DR. BASIL SANDS
Published: May 07, 2013
Aural hematomas is the term used to describe a swelling beneath the skin of the ear that contains blood. This is often as a result of trauma from scratching or rubbing the ear due to parasites (fleas or ticks) or an ear infection.
The ear cartilage is separated from the skin when the area between suddenly swells with blood and fluid. The soft swelling is usually on the inside, but can be on the outside surface of the pinna.
Aural hematomas most commonly affect dogs with floppy, pendulous ears that easily bruise when the head is shaken to relieve itchy ears. There is no sex predilection, but affected dogs are usually middle aged or older. The underlying cause must be treated as well as the hematoma. Clinically, aural hematomas result in large fluctuant swelling of various sizes, but usually affect most of the ear pinna.
During the first days, the swelling is warm or hot to the touch and the overlying skin erythematous reddened. The animal is greatly bothered by the increased weight of the ear and sometimes seems to experience pain.
Aspiration of fluid obtained within hours of hematoma formation is sero-hemorrhagic (bloody) and usually rich in fibrin. The normal evolution of a hematoma is resorption of the fluid and healing. Fibrosis is always a major feature of the aural hematoma of healing process, especially if left untreated. The ear becomes thick, hard and permanently distorted as the fibrosis in the wound contract. This is commonly referred to as a cauliflower ear. Because aural hematoma is rarely seen in dogs and cats with major trauma to the pinna, minor ear trauma and itching is more likely to be the precipitating factor than a primary cause.
The trapped blood must be drained to prevent the ear cartilage from scarring. When the hematoma is small, removing the fluid with a syringe, followed by firm bandaging for seven to 10 days may be sufficient. More commonly, the hematoma recurs in a day or two as new blood and serum fill the cavity.
Surgery offers the best results. The dog is anesthetized, and a small incision opens the inside surface of the pinna. The opening is drained and cleaned, and the separated flaps of cartilage and skin stitched back together. A narrow opening is left at the incision line so that fluid will drain as the incision heals rather than re-inflating the wound. Often, a soft, padded bandage is used to help the ear retain normal shape as it heals. The bandage may anchor the ear against the head or collar to prevent a recurrence of ear-flapping injury.
Some dogs that undergo this surgery are fitted with an Elizabethan collar to prevent their scratching at the wound.
Because the healing of aural hematomas is highly fibrotic, glucosteroids are flushed into the hematoma cavity. They are also given orally with antibiotics, at least until the sutures are removed and the incision has healed. Even though trauma is probably only a precipitating factor, it should be avoided as much as possible to prevent relapses.
• Dr. Basil Sands can be contacted at Central Animal Hospital at 325-1288.