Hi, I just posted in the welcome mat, here is the reason I was looking in the first place; Koda is 6months old and we have always taken him everywhere with us, he was always fine, then at a bit after 5 mo we went to the pet store and he went CRAZY at some other dogs-two full grown mastiffs by the way, when I apologized to the owner I said he's just pup and he's never done this before! He laughed and said he apparently doesnt know that! That first incident was followed by three others in public places, barking at anything that moved outside our car, the trash cans at the end of the driveway, then we went to a family thing and he met my brothers and uncles dogs, both full grown, intact males, and he did the same thing but he was loose and ran right at them, then back to me, then at them, alternately being submissive, and then his hackles up stiff legged, and barking, then yipping. Thank god they are both good dogs, they just growled a bit and showed teeth, and looked at him like he lost his mind...then after about 5 min he stopped, and 15 minutes later he was fine, the best behaved dog there in fact. Then a couple weeks later we went to another thing and he did the same thing, but it was a dog he had met before, and he was more agressive. He laid down with is toy and jumped up and barked at the other dog when he got to close, in the other dogs yard! My husband says he is being agressive, but doesn't know how because he's still a puppy, and needs to be fixed. Has anybody else had this experience?