I would consider a consult with a Board Certified Orthopedic Surgeon.
Buster had knees issues and we loved Dr Scott Anderson
ASEC Animal Hospital Doctors SurgeryASEC, Los Angeles, CA 310-473-1561 Here is a link for other Board Certified Vets.
ACVS - What is a Board Certified Surgeon?
There is a member here Linz06 and they went through a similar problem with her Layla
http://www.yorkietalk.com/forums/sic...out-layla.html
Sending prayers and best wishes for you and your boy