One of the benefits that a puppy receives by staying in the litter until 8 weeks (assuming the breeder is doing their job), in addition to bite inhibition, is learning how to communicate with their littermates.
Certain puppy signals say “let’s play,” “out of my space,” “easy,” or “no harm intended.”
It is these signals for communications that dogs learn as puppies and as adolescents which they carry into their adulthood. These signals, when used while playing, allow dogs to communicate with each other and to keep play at a reasonable and tolerable level and most of all fun for all.
Some dogs never learned these signals because they were not given the opportunity to interact and learn how to communicate. As they develop into adolescent pups and begin to interact with other dogs and puppies in the real world, they are unable to play normally. This is where normal play stops and threatening behavior begins to intensify.
These dogs begin to ignore all clear signals from their playmates that would normally keep the play at a fun level. The intensity of behavior is triggered at what is considered lower thresholds of play with the other dogs.
This type of aggression may also inadvertently be directed at humans who begin to play with the dog. Humans can accidently increase the intensity of the play to a boiling point and the aggression begins.
It is sometimes very difficult to tell the difference between play aggression and what is thought to be rough
I think that the lesson here is don’t rough house with your puppy and make sure that your puppy gets an adequate amount of socialization with people, kids and other dogs.
It is a “use it or loose it” kind of thing.
Rough play can escalate into aggression for some puppies. When we see rough play in very young puppies, there is a greater chance that some puppies will develop escalated behavior (aggression) as they mature.
Be as comfortable with the trainer of your dog as you are the teacher of your children. And remember, ‘OPPORTUNITY BARKS!”
Jim Burwell, Jim Burwell’s Petiquette