Our little lady Yorkie does that too. the only thing that helps us is to undo the tie knot or bow every day. A lot like you would with a 3 year old daughter’s hair.

Some people might focus on not letting the dog “play”, but I prefer to let them have some fun.

You could also train your dog that when they have the tie knot it is not time to play, but when it is off they can.

I have also noticed lately that some of the Westminster Kennel Club dog show contestants have been braiding the hair behind the yorkie’s head. I think its cute.

Hope that helps.