[gemy]

First it is very good of you to offer a for ever home to a neglected Yorkie. I am unfortunately not surprised to hear that a rescue did not either deal with his teeth issues or disclose his health status to you. I am a bit concerned with your leg description popping in and out - it might be his knees indicative of Luxating Patella or if his hips some congenital defect of the hip joint (s). Either one or both might need surgery down the road!

More than a few Yorkies can be notoriously hard to house train and for 5 yrs this one has not had the training. I would definitely restrict his roaming space in the house until he is 100% Treat him for housebreaking as a eight wk old puppy.

If he is walking well on a lead - I would try to wear him out with the walking. Spinning and fence running as you know can be a sign of a dog that is kept crated way way too long every day! So I would slowly try to work on that first by keeping him on lead and long long walks daily.

Dogs will and can learn from watching. So if your other dog is really toy driven and loves to play fetch and or find that toy - you can do that and let your rescue watch for quite some time.