Take Home Tips
The following tips will go against everything you want to do with your new dog, but it's imperative that you give him every opportunity to succeed in his new environment.
Imagine that you get off a plane in a new country and strangers are forcing themselves on you. They're loud, they're touching you, they're talking a language you don't understand. Pretty unnerving and uncomfortable, right? That's what your dog is feeling when you let your children maul him, when you invite the neighbors over to meet him, and when you force him to pose for selfies the first day in your home. Give him a safe environment and that will build trust.
Don't baby him. Don't feel sorry for him. Don't feed treats all day. Teach him that all he needs in life comes from YOU...food, water, affection, touch, and structure. There are thousands of videos and websites where you can find all the information you need.
Don't turn your new dog loose in your home with your current dogs and/or children. The dog will need time to adjust to the new sights, sounds and smells of your home and you can expect this to take at least a full month.
If you currently have a dog in your home there may be jealousy and guarding of it's toys and people. This isn't acceptable behavior. Don't make excuses for growling, biting or outright attacking by either dog. Consult with a professional immediately if you have problems or questions. Don't wait for the second, third, fourth or fifth dog fight to seek help.
Crate your new dog in a quiet place where they feel safe. Dogs instinctively search for a "den" when they are scared or want to be undisturbed. Make sure it's big enough for them to turn around in and lay down comfortably. There are many videos on Youtube for crate training so check them out BEFORE you bring your new dog home. If your new dog goes under the dining room table or into another room where it's quiet don't pressure them to come back out. They're telling you that they need to watch and listen from a "safe" distance and anything else is too much too soon. Learn what your dog is telling you and act accordingly...its setting you and the dog up for a wonderful life together.
If you want to walk your dogs together, leash them both and walk parallel and at least six feet apart. Take long walks frequently. Forward movement and calm energy will go a long way with helping your dogs get to know one another without direct contact. They have the rest of their lives to play one-on-one. This isn't the time to force them to be friends. Before you introduce your new dog to others, do some research on reading body language and the proper way to introduce dogs.