I don't know much about yorkie's yet but mine is 6 months old. She has had a cough, similar to kennel cough since I got her. The vet gave her anti-biotics for the cough and it never cleared up. My sister thought maybe she has a trackier problem but the vet said nope. She still coughs some, I am a bit worried but she is fine otherwise & we have lived with this for 4 months now.