Some Yorkies can have trouble with their back legs. My Spud is taking Dasuquin, a joint health supplement. It has glucosamine and chondroitin in it. It is to help strength his back legs. It is chewable and probably tasty because he chews one half a tab in the am after his breakfast. I get it from
www.petmeds.com You should check this out and get some for your dog. Also make sure he does not jump off couches or chairs. I have a set of steps Spud uses to get on the couch and bed. Oh what we don't do for our precious Yorkies! Sure hope this helps.