My dog Reno (mutt) actually did cause damage to Skye's (argentino/greyhound) ears twice when they were playing. They first time he ripped one ear and the second time he caused a rupture of one of the blood vessels in her ear. Her ear filled with blood (the vet called it pillow ear). We had to take her in and have her sedated and they put a drain in it. Once a day we had to put her in the bathtub and gently massage the ear to get the build up of blood out. Now she has scar tissue in that ear and she is really sensitive when another dog gets near her ears.