When introducing a new dog to a dog it is always best to have the first meeting on equal ground. Somewhere they are both new to. For example, let them meet in the park instead of your home where your older dog "owns" most of the space. You can also try wiping the puppy with a piece of cloth and letting your older dog smell that first before the actual puppy is shown. Just make sure that you supervise the 2 until they become friends!