Hi everyone, I'm new here and in desperate need of some help. My mom is thinking about putting our 2 year old Chesapeake Bay Retriever down.. for one reason. When people come to the door (family friends, strangers..) our dog goes NUTS! He'll jump up at the door, barking viciously and wanting to attack or scare the person away [which he does successfully]. He's very loyal and devoted to us, maybe even a little too attached. I think he's just doing his job to protect us. But now he's just getting TOO agressive to strangers. He tried to bite a family-friend yesterday who came to the door, but I put my arm in front of Byron [the dog] and he bit my arm instead. It didn't hurt too much, I just got a few marks. But he wouldn't stop going at the guy! With our old dog we could say "No!" and he'd be as happy to see the person as I was.. I'm not sure if he's doing this just because he's not neutered or he's just guarding. Please help! This is for the life of my dog! Another thing he does is chases shadows and light beams, which is just irritating! Our neighbour got him hooked on a lazer-pen beam when he was just a puppy, and he goes beserk trying to get lights. He chases flashlights, and even tries to chase cars' headlights. He even opens/closes the front door just to get a reflection going through the window onto the wall. How do I get him unhooked this habit? Any help is GREATLY appreciated. Thanks.