There is a lab that is a purebred lab that to me seems really strange. He is a nice dog, but it seems like he is a grouch, he growls at most people even everybody he has known since he was a pup. It's really weird because he growls mean like and will wag his tail, he has snapped at us before so we don't really trust him at all but majority of the time he is a great dog. He will also start growling if i pet him and stick his head underneath me but keeps on growling with lips pulled back. I was wondering about ideas on why he is like this. He's a pain in the ass but we love him any ideas please post.