Preparations for introducing your dog to a new baby should begin several weeks before the baby's actual arrival. It is important that your dog be well trained. He should at least know how to sit, stay, not jump up, and come when called. The main reason for training is to establish your leadership so that he/she will trust you not to abandon him/her when this new creature arrives and the bond will be strong enough for him/her to continue to obey your commands.
The first thing to do prior to baby's arrival is to get a doll. Sprinkle it with baby powder, wrap it in a blanket, cradle it, rock it, talk to it, and walk around the house with it. At the same time, praise your dog for not jumping up on you, by saying, "Good dog." Show the "doll baby" to your dog. Let him/her smell the baby. Give praise and food treats at the same time.
Next, get a recording of a crying baby and play it softly at first. Praise your dog, while listening, and reinforce his quiet behavior with a food treat. Each day increase the volume and continue the praise and food treat. Continue to expose your dog to the smell of baby blankets and powder. Invite a friend with a baby to your house. Reinforce good behavior with praise while the baby is visiting.
On the day of arrival, it would be best for you to walk in without baby and greet the dog. Then, someone else brings in the baby. If you can trust your dog's behavior around babies at this time, let him/her see, smell, and touch the baby. Do not worry if he/she licks the baby. You can wash it off later. Besides, a dog's mouth has less bacteria than a human's!
If you act happy and relaxed while your dog is in the presence of the new baby, it should not take more than a few weeks for him/her to accept this new littermate. If you are nervous about your dog's intentions for a good reason such as growling, you may want to consider using a muzzle when baby and dog are together. It is best not to allow a dog unsupervised access to a new baby for awhile. Some dogs are unnerved by loud crying and flailing arms and legs. Be sure you know your dog is comfortable in all situations before allowing unattended access.
Some dogs will break housesoiling rules for a short time after baby's arrival. They think that if this new littermate creature can do it anywhere, so can they. To discourage this from happening, do not leave dirty diapers lying around.
You may not have the same feeling of devotion and love toward your dog after your baby arrives. Be prepared for this surprising change of attitude. Your dog is no longer your baby. The important thing to remember is to try and give him as much attention, playtime, and exercise as before.