He weighs 43lbs and is 19 weeks old. I want him to be as big as possible. He gets Science diet food and puppy vitamins, but he just seems small. He hasn't lost his milk teeth; but he doesn't look like a puppy, more like a mini shepherd with big feet and ears, sans the mane (which is starting). I just think he should be bigger by now. His mother was medium size and his father was large. He was big enough to rear up and look down on me (I'm six feet tall). I don't know what to think. I just want him to be big. He's 7lbs shy of the chats which is like 13 percent, that seems pretty significant to me.