Never Ever! But then I don't really have to worry, my Yorkie is NOT friendly with other dogs. He was so scared when he first came here and met the maltese (the sweetest, calmest, lovingest dog) but now she is his best buddy. But the neighbors have a "puppy" yorkie and he snarls and growls and even goes after him when he is too "forward." So He sort of set the stage for no playing with "big" dogs. It's just not worth the risk, it only takes a second for things to go very badly and it is always the little guy that gets the worse of it. So no no no!!!!