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Cauliflower: It's not just a vegetable

5/27/2004

As a high school coach and referee for Big 10 college wrestling matches, my dad saw a lot of cauliflower ears. Trauma from grabbing, flipping, twisting, and even (*gasp*) biting resulted in swelling and occasionally ear deformity in more than one young man. The same sort of problem can occur in your dog, whether or not he participates in such rough extracurricular activities.

What is an aural hematoma?

Aural hematoma, the underlying source of "cauliflower ear," is a collection of bloody fluid under the skin or between the cartilage layers of the pinna — the upright or floppy skin appendage above the ear canal.

Aural hematomas are thought to be secondary to trauma. Vigorous head shaking in animals with external ear canal irritation causes the tiny vessels that perforate the internal cartilage to rupture and bleed. Although pressure building up under the skin will stop the bleeding, continued head shaking will cause the pocket to enlarge until it becomes a very noticeable and sometimes uncomfortable.

Not all dogs and cats that have aural hematomas have ear infections; in fact, between 15% and 45% of affected animals may have no evidence of external ear canal disease. Because head shaking is thought to be the underlying traumatic event that leads to hemorrhage, ear and skin examinations should be performed by a veterinarian on all affected animals to rule out or diagnose predisposing conditions. Allergies to food or reaction to chemicals in the environment may be underlying causes in many dogs.

Treatment of aural hematomas can either be medical or surgical. Surgery will rapidly reduce the size of the fluid pocket, but may result in some disfigurement and usually requires 2-3 weeks of bandaging or drain care. Medical management requires the use of steroids to reduce pain and inflammation and to control the underlying cause of the ear canal irritation.

Steroids should never be given to dogs that are receiving medication such as Rimadyl or Deramaxx for arthritis or other painful conditions, since dogs on these drugs are more prone to gastrointestinal ulcers and upset. Your veterinarian will help you decide which treatment is best for your dog.

Medical management

Conservative treatment involves drainage and flushing of the hematoma through a small incision or with a large needle, and administration of corticosteroids by mouth or into the hematoma cavity. The cavity can be injected once daily with dexamethasone (a short acting steroid), or weekly with methylprednisolone acetate (a long acting steroid) until the hematoma resolves.

Animals treated with daily intracavitary injections of dexamethasone usually heal within 3-6 days. Animals that receive intracavitary methylprednisolone acetate may require a second or third injection, but most resolve with a single treatment.

Bandaging of the ear is not necessary except to seal the drain hole or to prevent vigourous shaking. Hematomas resolve in 90% of patients treated with local infusion or oral administration of corticosteroids, most likely because the irritation caused by the underlying problems (i.e. allergies) has been treated as well.

Surgical treatment

A variety of surgical treatments have been used for aural hemotomas. The hematoma can be drained and flushed through a long S-shaped incision on the inside surface of the pinna.

The separated layers of tissues are then apposed with through-and-through sutures to keep the cavity collapsed and compressed. A gap is left at the incision to allow continued drainage of the hematoma, and the ear is bandaged down across the neck or up over the head to prevent self-trauma and to absorb additional fluid. This type of treatment allows the hematoma cavity to be cleaned out well; however, the ear may thicken and wrinkle as it heals, leading to permanent deformity.

Alternatively, the hematoma cavity can be drained with a teat cannula, a small tube used to drain infected cow udders, or with a continuous suction drain made from a butterfly catheter. A suction device (a vacuum tube used for blood collection) is attached to the butterfly catheter to keep negative pressure on the drain. The ear is bandaged against the dog's head or neck, and the vacuum tube is changed as needed to maintain continuous suction and compression of the hematoma cavity. In most dogs, drains must be left in 2-3 weeks, since early removal will often lead to recurrence of the hematoma.

Carbon dioxide lasers have also been used to make drainage holes and to stimulate the layers of the ears to heal together. As with the other surgical techniques bandaging is usually necessary to keep the ear compressed until it is healed.

Healing of aural hematomas with surgical treatment is usually seen in 60-83% of dogs; some may require a second or third procedure. Surgical success is best when the underlying cause of the ear or skin disease is treated.