Another thing I hate to bring up, but we have a university near us that does animal research. If you have one near you call and see if a dog matching Yoshi's description has been sold to them. If not ask that they put an alert out not to buy a dog matching his description that he was stolen and you want him back, to notify you if one turns up there.
I'm thinking someone is keeping him for themselves, alot of people want a Yorkie but can't afford one.
__________________ Mammadoodle to my Yorkiedoodle Barney and our crazy cat Ms. Sassy Pants.  RIP Audrey-Belle 
Within the heart of every stray lies the singular desire to be loved |