Griffy came from a home where he was regularly kicked and hit by a 4 yr old and other large dogs as well. Now he doesn't like young kids or anyone who is particularly aggressive with him. He knows how to sit and is crate trained. He plays with most other dogs but is a bit aggressive with larger dogs, like he doesn't realize that their size can outdo him in a heartbeat. He plays quite well with 7 of the dogs currently in his foster home. The two he doesn't get along with, to be honest, are aggressive themselves, so I think it's more a defense thing for him. I had the pleasure of dog sitting him, along with his canine friends at his home and saw NO aggression with any of the dogs. He learned quickly to come in and run STRAIGHT to his crate for the reward of a treat. Fast learner, who wants love and wouldn't mind a playmate closer to his size. NO YOUNG kids (under 10 yrs of age)