Introducing a new dog to your current pets can be difficult. Dogs are very territorial over their home and their family unit and they want to protect them both.
When you pick up your new dog do not bring your current pets with you as forced confrontation usually does not work. It is recommended to wear clothes that smell of your current pets or your pets blanket. This will help your new dog get used to the smells of your current pets.
There are lots of ways to introduce a dog and it wll depend on your pets character which way is best.
The key is to introduce your pets slowly and do not force them together as if they have a bad experience then they will associate each other with the bad experience and will not get on.
One way is to have your current pets in a seperate room and then let your new dog explore its new surroundings. Once your new dog has explored the majority of its new surroundings and has settled down, then put your new dog in a dog cage and let out your current pets. Let your current pets smell your home and your new dog, make sure you priase your pets when they show behaviour that you are satisfied with.
Once you are satisfied with your pets behaviour then let out your new dog and stay close by. The dogs will probably sniff each other, however they may decide to ignore each other or try to play. If they don't want to interact, do not force them to and only intervien if one of the dogs becomes aggressive.
Alternatively if you do not have a cage then you can introduce your pets with smells, keep your pets aprt and give you new dog a blanket from your current pets and vice versa. Then slowly introduce your pets to each other and keep a close eye on them and intervien if they start fighting. Do not punish your current pets for growling at your new dog, or they will associate the new dog with an unhappy experience.
Reassure all of your pets that they are equally loved and do not ignore your other pets as they will begin to feel neglected. Do not ever leave your new dog unsupervised with the other pets until they are all familiar and used to one another.