An aural hematoma is a collection of blood within the cartilage of the ear and the skin. It usually arises as a self-inflicted injury from your pet’s scratching and head shaking. The underlying causes include all conditions that result in otitis externa (infection of the external ear canal).
Hematoma formation has also been associated with increased capillary fragility (e.g., as seen with Cushing's disease). Aural hematoma is the most common result of physical injury or trauma to the pinna (the “flap” of the ear). The condition is common in dogs with chronic otitis externa and less common in cats.
Sources of irritation to the ear linked to the development of an aural hematoma include:
- immune mediated diseases
- foreign bodies
- trauma (bite wound or blunt trauma)
Most animals usually have an associated infection. Recurrence of the condition is common if the underlying condition is not resolved.
Swelling associated with an aural hematoma is most apparent on the concave inner surface of the pinna (Figure 1). The swelling is soft and warm in the early stages. With time, scar tissue will thicken and deform the ear, resulting in a cauliflower contracture.
A few simple tests may be performed to make sure there is not an underlying reason for the ear being irritated or hard to heal from the bleed.
- fine needle aspirate and cytology
- systemic testing for underlying causes may include
- allergy testing
- ear swabs
- endocrine testing
Deformity of the ear can occur if the condition is left untreated. This typically will leave the animal with a “cauliflower” ear. Potential complications include:
- cosmetic alteration of the ear
- recurrence of the hematoma
- necrosis (death) of the pinna
A bandage should be placed to protect the ear from infection and self-inflicted trauma. Infection can occur in the surgical site if surgical wound is not managed appropriately with bandages.
Aural hematomas seldom recur if they are properly treated and the underlying disease is appropriately treated. This condition can be prevented by providing prompt attention to conditions that result in irritation of the ears.