However, this can also occur after grooming. If your dog is extremely mated to a point that the hair must be removed from it's ears, Hematoma of the ear flap, may result. This happens for the most part because of the weight difference. Matted ears are very heavy, it becomes heavy, generally over a time span. When the hair is removed, the weight difference is dropped all at once, This can irritate the dog's ear, causing the dog to begin to shake its head repeatedly in a vigorous manner.

If this happens please consult your Vet for treatment. Sometimes it is necessary for the vet to surgically drain the accumulation of blood.