It is not uncommon for dogs to change following a traumatic upheaval. Most dogs are creatures of habit—they like things to stay the same. And now your dog is suddenly in a new town, in a new home, and surrounded by unfamiliar people.
You can help him overcome his doggy post-traumatic stress by adhering to a schedule of feeding, walking and training that is as close as possible to what you did before the move. Make sure he receives at least as much exercise, if not more. When you take him out for walks, carry very tasty treats or an irresistible toy, and distract him whenever a stranger approaches. This will disrupt the barking and teach him to expect good things whenever a stranger is near.
It’s also smart to teach him to stay in a comfortable place in your home, away from the door. Train him in advance to understand that when guests come to the door, he is to go to this place. Arm the guest with treats and toys and, if you’re sure he’s all bark and no bite, let them meet. If you’re worried that he might bite, however, do seek help from a behaviorist or certified trainer.