My 8 week old german shepherd/bernese mountain dog puppy is very sweet and cautious about other dogs.. he tends to sit back and observe and then tries to jump in and play when he feels comfortable. He has played with a few large older dogs (age 2 & up) and he lives with our 10 month old lab who is very patient and gentle with him.
Today my friend brought her dog over to have a "puppy play date" (he is a 3 month old rotty, bull mastiff, lab, shepherd cross) and he was VERY aggressive towards my puppy.. He is aggressive in general but he has played well with our lab in the past and I thought he would be okay. Well I'm talking vicious.. he was growling and full on cornering and biting my puppy as if he was attacking him. My puppy in the end was growling back and trying to defend himself and I separated them immediately whenever they started to get this way. I have many scratches and bite marks on my arm from having to jump between them and pull my puppy up into my arms. It's safe to say I won't be letting them play together again.
Will this have an impact on the way my puppy views other puppies now? When socializing, should I only let him be around very nice and gentle dogs, perhaps a bit older so that he doesn't develop any of these aggressive tendancies? I don't want him to think he has to defend himself every time he sees another puppy coming over to play.