How to introduce new dogs?
I suggest having a trainer assist you with this. Start off really slow. Avoid doing face greetings as they can be intimidating to some dogs. Start off by walking the dogs. Each dog has a person. When the dogs seem comfortable, go to a neutral and safe place where they can be off leash and free to run away from each other if needed. Next, have them meet outside of the house couple of times. Slowly let them into the house to play.
Do you need a trainer to introduce your new pet to you existing one?
I strongly suggest you find a trainer or behaviorist to help you with the initial introduction. This video is more of a guide after you get advice from a local professional who has met both dogs and can help you best to introduce them.
Here are some registries of behaviorist and dog trainers in your area:
Do not force the two dogs to interact with each other. Take lots of time and lots of patience with it. Always start off in a neutral place with lots of rewards and praise. You want to show that the new dog is not a threat to your dog and that they can be friends.
Step by step guide to introducing new dogs to each other:
Step One: Learn about dog body language so that you are able to identify when a dog is getting aggressive or is uncomfortable. Here are some helpful sites for that:
Step Two: Let them get to know each other slowly and carefully. Forcing two dogs to be together in a yard or in a house can lead to heartbreak and occasionally, serious injury.
Step Three: Have the dogs meet on a leash in neutral territories like a park or a neighbor’s yard or on the street up from your house.
Step Four: Let them sniff each other FOR THREE SECONDS during the walk and still on leash.
Step Five: Let them meet while dragging their leashes.
Step Six: Have the dogs meet at the house.
Step Seven: Do not leave the dogs alone!! Keep them in separate rooms or in a crate.