Sometimes when pups don't get early socialization they can be missing communication skills they need to be able to confindently interact with other dogs. Without confidence dogs can become defensive. One of the things we do is help dogs that have missed this early interaction with dogs. From what we learned this pup possibly missed a lot of his much needed early pup on pup play. With remedial socialization he has come along way. When we met him he really wasn't sure what the heck to do. He's now enjoying play and positive interaction with his friend seen here.