I am not a behaviorist, but one trick that may help is to begin hand-feeding. All food should come from you in return for some requested behavior: sit, quiet, down.
Have you done any obedience training? It does help, though many of us don't bother because these guys are so small.
I hope others will chime in.
__________________ Janet  , Gracie  , and Millie  , and Maggie |