The earflap consists of a layer of skin on two sides with cartilage in between. Aural hematomas in dogs and cats occur when a blood vessel ruptures in between these layers.  As the blood flows between the layers it causes these layers to separate from each other. Eventually the dog's or cat's ear looks like a miniature pillow.

For years it was thought that the rupture was just caused by some sort of trauma to the ear, and that surgery was needed to repair the problem.

While trauma could certainly play a part, it is now believed that the ear is predisposed to this problem due to an inflammation of the arteries in the ear flap (arteritis).

The good news is that we can actually cure over half of aural hematomas in dogs with an inexpensive medication given by mouth, rather than surgery. Thereby saving the dog or cat from surgery and saving hundreds of dollars for the owner,