Hi:
I think that the thing to remember is that Yorkies are small dogs, therefore, there bladders are very small. When you think about it it makes sense. If a yorkie is urinating alot, he probably has too much water in his bladder. His little body will absorb what it needs and just dump the rest! I offer my comet a full bowl of water twice a day, during his feeding times only. i agree with the trainers. It works for us.
Good Luck, Cometsmom