Leave a bottle of baby oil or lotion open. If special detergent will be used for the baby's clothes, allow the dog to sniff the clean clothes. A cat might enjoy his favorite blanket or bedding washed in the same detergent. The days before the newborn is to come home, the infant's scent should be introduced to the pet. If the master is the new mom, a familiar person should come home with a piece of clothing or a blanket for the animal to smell.
Dogs usually take it and slobber on it.
It is important not to reprimand the animal for his reaction. They, too, are excited. The day of the arrival, it would be best to bring home a dirty diaper for the dog to smell and do with it as the dog seems fit. This is the best way for dogs to get familiarized with the baby's scent without slobbering on the infant. Weather permitting, clean up is easier if it's done outside.