Have you thought about getting some training for Louie before you decide about getting another dog? They will train u as well on how to handle him properly. Louie seems to be having dominance issues and that won’t stop until you show that you are the alpha and not him. The trainer will help you with showing Louie the proper ways to act towards other dogs and how you can keep control of him even though he is stronger. It is definitely something to look into before getting another dog so that the new dog doesn’t pick up Louie’s bad habits.