I was reading in a book about the reasons dogs bark (boredom, anxiety, and offensive and defensive barking.) Defensive barking is done out of fear of someone approaching, the dog will look frightened and is using the barking as a shield. Offensive barking is also done when the dog feels threatened, but is using the barking as more of a "spear" to fend the threat off. An offensive barker will be on the alert, ready to charge. The book said both of these behaviors can lead to aggression and should be dealt with by a professional dog behaviorist if you want to control the behavior. Louie is starting to display classic chihuahua traits of protectiveness and wariness of strangers. If we're outside and someone is walking down the street on the other side of the street, not even coming towards us or even aware of our presence, he will send out his bark spears to fend them off. Classic chihuahua behavior or not, I find it rude and would like to stop it, but I'm not sure what the best way is. I tried a Cesar Milan "poke" to distract him from what he's doing and then say "NO" firmly, but it doesn't phase him in the slightest. I've tried picking him up and telling him I'm in charge, and I say there's no threat here, nothing to be alarmed about, but of course he doesn't understand what I'm saying I've had some success distracting him with a treat and asking him to do some obedience commands, which works alright, but I'm afraid presenting the treat when he's barking at someone could be taken as a reward for that behavior. When he's finished with the exercises, he goes back to barking at the person, even if they're not in sight anymore. He acts better when we're walking down a busy sidewalk surrounded by people, he defers to me and walks by my side without paying attention to anyone. It's mostly when we're alone on a quiet street and then someone appears. Please help, I want to nip this in the bud while he's still a puppy before he gets set in his ways.