Hi, Welcome to YT.
For now i'd give him all the antibiotics to help clear up the UTI. They will help. Also for now i'd give him the SO. i like the royal canin better then Hills so i'd stick with it for a few weeks/months to get things under control. Then i'd look into other diets to help prevent stones/crystals. I believe other people here have had these problems with their yorkies and have found other diets that work which are higher in quality.
Also i wouldn't feed the SO to your other yorkie. Keep the other one on the same food he's been eating.
__________________ Kellie and Morgan |