The most serious problem that can occur is that your dog may not recognize your baby as a human being to be included in its family unit. If a dog is not familiar with infants, particularly within the family, the dog may interpret the infant as a prey item. Most dogs are curious about infants. This is particularly true if a dog has had little exposure to infants or a long time has elapsed since it has seen a baby. If you have observed its reaction to other babies, either in your home, on the street, or in other people's homes, you should be aware of your dog's typical reactions and take any precautions that are necessary.
Most dogs adapt quickly and easily to the presence of a new baby.
Since the consequences of a problem can be so severe, however, it is wise to assume that your dog could act adversely and to take all the safety precautions possible, regardless of your dog's previous encounters with babies. A baby could be accidentally hurt as a dog attempts to play with or investigate the infant. Any dog with a known history of aggression toward people requires particular caution. A dog that is aggressive towards visitors, mail carriers, or even other dogs could injure a baby if the child happens to come between the dog and the object of its aggression. Dogs that are aggressive when approached while eating or in possession of a bone, toy, or other favorite item or those that are aggressive if startled or when awakened require very close supervision in the presence of a baby.