Aural Hematoma in Cats
Dr. Nicholas Trout
Veterinary care should include diagnostic tests and subsequent treatment recommendations. Your veterinarian will evaluate the ear closely and will palpate (feel) the swelling.
Your veterinarian will also examine the external ear canal. Visual inspection of the ear canal may be followed by otoscopic examination. Some cats may tolerate this procedure quite well, but others may resist and squirm, necessitating sedation or even general anesthesia. For this reason, a detailed examination of the ear canal may be done at the time of surgical treatment of the hematoma.
Visualization of the horizontal and vertical ear canal, together with the tympanic membrane or ear drum, is essential as part of the work-up for an underlying cause of the aural hematoma. Cultures may be obtained at this time to see what bacteria or fungi are growing in the ear and to what medications it is sensitive. Cotton-tipped swabs can obtain samples from the ear canal, be smeared onto a slide and evaluated under a microscope for parasites such as ear mites and yeast.
Skull radiographs, in cases where underlying external or middle ear disease is suspected, are also obtained under general anesthesia. Radiographs are only necessary if the canal is narrowed and occluded, preventing visual evaluation of the ear drum. When available, computed tomography (CT scan) or magnetic resonance imaging (MRI) can be more helpful than radiography to evaluate involvement of the middle ear.
Medical management by needle aspiration is rarely successful. Injection of steroids into the empty pocket, following drainage, has been reported. Recurrence with these techniques is extremely high.
Surgery aims to remove the hematoma, prevent recurrence and retain the natural appearance of the ear.
The most common surgical technique involves making an S-shaped incision on the concave surface of the ear, over the hematoma, exposing the underlying cartilage from one end to the other. Blood and clot from within the swelling would be flushed out.
Prior to surgical management, your pet should receive a thorough preoperative examination. At this time, blood may be drawn to check a variety of body systems before receiving general anesthesia. A urine sample and chest radiographs may also be necessary depending on your pet's age and level of health.
Under general anesthesia, the ear will be evaluated and, if necessary, cultured, and the ear canal will be cleaned and flushed.
Sutures are placed through the skin on the concave surface, either through both cartilage plates and below the skin, or through both plates and out through the skin, and then back to the concave surface. The sutures are about 1 cm in length and run parallel to the major vessels of the ear; that is vertical, not horizontal. A sufficient number of sutures are placed around the incision to obliterate any remaining fluid pockets.
Your veterinarian will NOT suture the incision closed. Instead, it will gap slightly to allow for drainage.
Some veterinarians may prefer to insert a narrow (1/4 inch) latex rubber drain into the swelling, leaving this in place below a dressing for the ear for 10 to 14 days. The dressing will help apply pressure and the drain prevents fluid accumulation. A teat cannula, originally designed for use in milking cows, can be modified for the same purpose. Both alternatives work well, and your veterinarian may have had good success with these methods.
A bandage can be used to protect the ear following hematoma surgery, but maintaining the bandage can be difficult. Patient tolerance for the bandage is often limited. When a bandage is used, the ear is placed over the top of the head, with non-adhesive dressings and cotton padding to protect the surgical site and offer gentle compression. Vetrap® or stockinette can be used as the outer layer. An Elizabethan collar may be a better alternative for many cats. Where medications are required for the ear following surgery, the bandage can be a problem in that it restricts access to the ear canal.