hi, welcome to YT!
When you say sores, what kind of sores? Does she possibly have ringworm? Or wonder if it's leather ear - which can affect more than their ears. What do the backs of her ears look like? This is a condition that can be worse in the winter.
We are dealing with this right now. Here is a link to more information about this. Scroll down about 3/4 of the way for the info
Alex's Yorkie Care Frequently Asked Questions. Page 3.
I have been using several things to treat this.
I am using an excellent shampoo I got from my vet - I would highly recommend it: Photoclens by Ayuvet from Tomer Labs - you can buy it directly from them natural herbal treatment -
natural herbal treatment - tomer laboratories - natural quality herbal remedies -- this shampoo is wonderful - the dogs smell wonderful & their coats are beautiful, I may keep using this from time to time once I know for sure the condition is all gone.
Here is what I found about the ingredients
oils of Himalayan cedarwood
Cedarwood Himalayan Essential Oil, Cedarus Deodora
Eucalyptus leaf oil
Eucalyptus Essential Oil, Eucalyptus globulus
I am also using the tree tea oil and Lotrimin on a regular basis - we have had major improvements & new hair growing - on noses, ears, and paws