My girlfriend has chiuaua's. They had a lab who was playful with /and always fine with the little ones, but one day I came by to pick up my son and she was screaming frantically, the lab got too playful and little chiquita was all chewed up! I rushed them to the vet who thought the pups back might be broken. All turned out OK, if you can call it that, needless to say, the Lab had to find a new home. He wasn't trying to hurt her, but maybe confused her with a chew toy??? It is a big risk. I always tell people, the first thing someone says when their dog bites or kills a tiny pup "She has NEVER done that before"
It just takes a second.