Ear Mites

Kristy Winfrey wrote Why are ear mites in pets so dangerous? which appears at the Newark Examiner website. The author notes that ear mites are parasites and that they can be spread from one animal to another. Ear mites fall within a classification of organisms known as Arachnida which also includes spiders. Outside they can be found on plants and trees but their penchant for living within the ear canals of our pets causes the vexing problems that demand attention. Quoting from Kristy Winfrey's article:

There is no way to completely identify mites without a microscope but there is one symptom that gives it away. If your pet looks like it has dried coffee grounds in their ear, they probably have mites. This discharge is dried blood, ear wax and the mites themselves. Another symptom is if they are shaking their head, scratching their ears or holding their ear in an unnatural way. There may also be a foul odor, but not always.

Ear mites can be effectively treated with ear drops. This online site has more information including teatment details.