I can't think of anything Bowser's afraid of. I don't think he even went through a fear imprint stage, he's just a very happy guy. The only thing he didn't like was when we were in puppy class and he had to go up the triangle looking ladder dogs use for agility trials, he didn't want to get on it but only because the first time he almost fell off. We ARE going to a place where fireworks are allowed within city limits on the 4th so I hope he doesn't freak out too badly. :( Anyone have any suggestions for this? And he did bark at the vacuum cleaner once but not since we did this, which we learned at puppy kindergarten: First with the vacuum off, put treats on it and encourage your dog to get them. Then do the same but moving the vacuum back and forth, try to get him to get a treat while it's moving. Then turn it on, but not moving. Then move it. Good luck.