Hi, I have been noticing a lot of dogs having coughing/ breathing issues this year. In Buster's case it is allergy related and perhaps that is the case with your Yorkie as well. Here is a link to different videos so you can compare your Yorkie's cough.
http://www.yorkietalk.com/forums/die...d-trachea.html
Best wishes. We always go to the worst scenario when we worry so I would go to a vet and have them check your baby out.