My dog has this nasty black stuff in her ear.

Question
I have a 10 yr old mutt and she had surgery on her ear to remove a hematoma about a year ago. Her ear now stays down instead of up. About 3 weeks ago I noticed some black gunk in her ear so I tried to clean it out some ear cleaner. Since then I've been cleaning it out once a week, but it isn't getting better. It smells gross and now every time I clean her ear it hurts her. What could this be? Is it ear mites or infection? If so, is there anything I can get from a pet store to help?

Answer
This is most likely an ear infection.  Usually it is the infection that makes the dog shake the ears to get hematomas.  I would see if your vet can do a deep ear flush and examine the eardrum to see if there is a deep bacterial middle ear infection causing all of this liquid, odor, and black gunk.