I would take them to do a met and greet before you pick up the other dog. Do this away from your house. That way your current dog does not feel their space is being invaded. Allow the dogs time to get to know each other. IF that goes well you should have no problem. There could be a few little scuffles and growls. This is normal. They are setting the pecking order in the pack. Many people don't look at things from a pack mentality. We tend to look at things as a family. That is NOT how the dogs see things. They see your family as a pack. They just have to figure out where they fit in. The chain of command is important for happiness. Do not try and interfere with this process. Often it will get settled and you won't even notice it. Hope this helps.