oh, how awful for those babies. My Bichons use to have problems with those & it was a continuous battle. Here is a website with a lot of natural or home remedy type cures
http://www.earthclinic.com/Pets/hot_spots.html
Maybe someone else will have a better suggestion on YT.
I'm wondering what you are feeding your yorkies?? I really think now, that my former dogs problems were probably tied to a food allergy more than anything. So I have much guilt over not knowing more about selecting a holistic food. I was feeding Iams and was so proud of myself - but now I know so much better.
Welcome to YT. Hope you stay around this is a great, knowledgeable site filled with fun, warm people