How to best introduce a new male GSD puppy or adult to my female GSD?

Yes, they can get along, but I would make sure your male is neutered if he isn't already or you will get puppies. This website will give you tips on introducing them: http://dogtime.com/dog-health/general/712-bringing-home-a-second-dog-aspca

Sorry, my answer was cut off. That will arouse Bruno's territorial instincts to protect his area and will likely cause problems with the new puppy. Instead, take both the dogs to a neutral location where neither has ever been and introduce them there. That way, Bruno will be bringing his new buddy home instead of resenting him as an intruder. if you need further help with this, Just click on the prompt to initiate a consult. Good luck!

With any two dogs, it's never possible to completely predict whether or not they will get along - they all have different personalities, just like people. But in my experience, I have not found GSDs to have any more problems with multiple dogs in a household than any other breed - indeed, I have several clients with multiple GSDs who all get along fine. I would recommend getting a female if you can, since male/female pairs are the least likely to have any aggression issues with each other. Best of luck with your new dog, if you decide to get one :)

They should be fine together, of course it is highly recommended to have them both neutered to avoid any aggressive tendencies, you should also introduce the puppy under your supervision only for a long time until you are sure your dog can be trusted.

Most dogs do well with a companion in the home. It will take some initial training on your part to get Bruno and a new puppy used to each other. I would recommend not leaving the new pup alone with the older dog until they are used to each other. It is also important to make sure the older dog still gets plenty of attention and exercise when the new puppy comes along. Good luck!

I'm so glad you and Bruno have a strong bond! I don't think it's a definite that he and another dog will fight when the puppy grows up. However, I would recommend that you introduce them carefully and slowly, and always monitor their interactions until you are certain that Bruno isn't going to play too rough with the puppy. In addition, I would consider having Bruno neutered, as testosterone increases aggressive tendencies and can certainly contribute to dog-on-dog aggression in some cases.

This is a great question! Adding a new dog into a household will certainly change the dynamic of things. I would be hesitant bringing any large breed adult dog into a house with a small breed dog without having the dogs meet first. However, since you are considering adopting a puppy, I would have no major hesitation. Each individual dog has a different temperament and reacts to animals, people, and lifestyle changes differently. There is never a guarantee that any housemate dogs will get along as time goes on. Since the puppy would only be able to remember his life with Wilfred, unprovoked attacks seem unlikely. If you go forward with bringing a puppy into your house, make sure Wilfred's lifestyle is relatively uninterrupted. Make sure he has a safe, comfortable space away from the puppy. Be sure to feed them separately - even in a separate room if one is possessive of food. Continue showing Wilfred plenty of love and make sure he has alone time with you.