I also had the same problem with my puppy and looked to a Petsmart trainer who told me that when strangers come around, they shouldn't give him eye contact when reaching down to pet him (apparently according to Rockie my 7 month old--if you give him eye contact he'll have to fight you for status I guess). In any case it is working and after awhile he is much friendlier and that same person can actually look at him after a period of warming up. I also noticed that he is much less aggressive when I am not with him and especially if I am not holding him. I never hold him with other people around because he always acts aggressive if a hand or a person comes near me. I am planning to enroll him in the next training class they offer to try to field the ever present "he won't come to me" yorkie quirk.--we'll see if they can figure that out. Good luck and if you find something else (I've tried the treat thing but unless it's people food-which I try not to give him) he's not interested in dog treats (his taste changes week to week-ugh!)
