I did a little research on the web. You may have already come across all this, but I didn't know. Hopefully it will help you out?
Why does my yorkie have black slimmy ears?
Pure silk yorkies will get leather ear, soft coated yorkies do not. Leather ear does affect silky coated Yorkies. It can be caused from colder weather and high humidity and can be responsible for hair loss on the ears, hocks, and the end of the tail and leaves a slimy black substance in those places. Some people think it is a fungus and some think it is a "rabbit mite". What I use to help this problem is #1 All Systems Tea Tree Oil. You can buy it from The Show Dog Store. The #1 Systems Tea Tree Oil Tea Tree Oil is a spray natural product which is anti-fungal, anti-bacterial, antiseptic, analgesic. Great for insect bites, hot-spots, fungus infections, cures all type of sores. It contains a natural sovent which allows it to be absorbed into the skin along with its healing properties.
http://www.northern-lites.com/info.htm
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Q. My dog has black slimy ears now and I was told this was winter ear. What can I do about it?
A. Leather ear, slick ear, English ear, black ear does affect some toy dogs, namely Yorkies, rather seriously. It can be responsible for hair loss on the ears, hocks, and the end of the tail and leaves a slimy black substance in those places. Some people think it is a fungus and some think it is a "rabbit mite". Frankly, having spent hundreds of dollars in the 70's to cure it, I still can't tell you what it is but I can tell you how to keep from getting it or how to get rid of it once you've "got it".
At the first sign of black around the edges of the ear, wipe the ear with "dog-o-dontic pads" dipped in alcohol.
Bathe in Betadine or Plexadine Shampoo, paying particular attention to the ears, end of tail, and hocks.
Use Ear Guard by Gerard Pellham regularly in the ears and cover the ears, hocks, and end of tail with a thin coating of Lotrimin 1%....no other kind of Lotrimin...just Lotrimin 1%, every day until the problem is solved! You will notice the ear begin to get very dry. Stop using the Lotrimin 1% if the ears get too dry! Another product which I have recently used for this problem is #l All Systems Tea Tree Oil and I'm happy to say that it works! This stuff is also really good to spray on "wrappers" as it is not too tasty!
Softer coated dogs never seem to have a problem with this but the silky coated dog with a lower skin temperature seems to have a problem when colder weather and high humidity prevail. Keep the dogs warmer and wash them at least once a week using Betadine or Iodine shampoo in those areas which are susceptible. You will be in control if you follow these instructions. It is also a good idea to have your veterinarian do a thyroid function test on dogs with these symptoms because some dogs with this problem also have a low thyroid function and medication may help the situation and keep the dog from becoming sterile and the bitch from having unusually small litters.
http://tsfannymaelivershuntfund.home...com/QandA.html
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My yorkies ears are covered in black stuff, what can I do?
The black coating is referred to as Leather Ear, or Winter Ear, and it is thought to be a fungus. What I have found useful in clearing it up is washing the ears daily with head and shoulders shampoo and letting it set on the ears for about 5 minutes, then rinsing if off. Within a few days the black can be peeled off the ear. Another remedy that is supposed to be good is to use alcohol to wipe the ear down and coat with Lotrimin 1%, doing this daily until the condition is gone.
http://yorkieviews.com/faq.htm
Good Luck!!