Let's start with some pictures taken several weeks ago. What do you think? Is Bernie (he is the one with a short coat and no collar) a vicious and aggressive dog who attacked Tommy (with blue collar)? Look closely and decide.
The truth is it was all play. Bernie (a five-year-old neutered male) is a friendly and outgoing dog who has never been in a dog fight...ever. He is one of the most stable dogs we have had. For the lack of a better term, I'll say that he expresses himself with his mouth and teeth (which we can see easily as he does not have a beard). When Bernie rests on a sofa he has to have a piece of blanket or fleece in his mouth, and he sucks on it. He does not destroy it, just puts it in his mouth. He is a very playful dog, and a great playmate for young dogs of both genders.
Tommy, who is almost three years old, is pretty much at the bottom of our pack. He submits to Joeri and Paika, also young dogs. He loves to play with other dogs but sometimes he pesters them too much and often this is a case with Bernie. It is Tommy who starts the interaction, but after a while Bernie has enough and usually puts him in his place. No harm done, they are friends at the end of the playfighting.
To the outsider the whole situation (which lasted at least 15 minutes) might seem risky and explosive. Bernie exposes and uses his teeth and growls a lot, pounces on Tommy, who finally rolls over. I think that Tommy learns something during these sessions. I have never noticed him having his teeth out when he plays with Bernie, but I have seen him doing it with Quenotte, the only dog here that he is dominant over.
Few years ago I attended a workshop with Susan Clothier, where she talked a lot about observing canine body language. I remember her saying that sometimes it is very hard to say when dogs are just playful versus when they are starting a fight. According to her the difference in the body language can be very subtle - as long as dogs are willing to make themselves vulnerable and "self-handicap themselves" all is good.