Took my Bitsy to the groomer last Friday and she told me the same thing! To be honest I didn't ask how she got them, probably from going outside. She treated her for them and gave me some ear cleaner and treatment for them. I have to treat her everyother day for 10 days, she doesn't like it very much (it's drops for her ears), I guess because it's cold!
Anyhow...I had to go to the groomer today and get her food, she said her ears looked really good and I've only given her two treatments!! Good luck, hope I've been of some help!!