Helping your pet adjust to the arrival of a new baby is much like preparing a young child for a new sibling. An infant brings many changes to a household, however, you can help your pet adjust to the big changes with minimal time and effort by making gradual adjustments to your lifestyle before the baby arrives. The best time for you to prepare your pet and make many of these changes is during your pregnancy. Cats and dogs are sensitive to routines, and by making changes now, you minimize the chances of your pet resenting the baby when she arrives.

• Sounds & Smells
  Most pet experts, animal behaviorists and veterinarians agree: it's extremely beneficial to expose your pet to baby sounds and scents before mom and baby come home from the hospital. For example, play recordings of a baby crying, turn on the mechanical infant swing, and use the rocking chair. Make these positive experiences for your pet by offering a treat or playtime. Sprinkle baby powder or baby oil on your skin so your pet becomes familiar with the new smells. Encourage friends with infants to visit your home to accustom your pet to babies. Supervise all pet and infant interactions. Bonus tip . . . Get a sealed container for soiled diapers. Cats and dogs are very attracted to odors. They just love dirty diapers and will drag them around the house.
• Environment
  If you'll be redecorating or rearranging your home, do it long before the baby arrives. With your supervision, let your pet explore any off-limits areas, then exclude him from these areas before the baby arrives. If the baby's room will be off-limits to your pet, install a sturdy barrier such as a removable gate (available at pet or baby supply stores) or, for jumpers, even a screen door. Because these barriers still allow your pet to see and hear what's happening in the room, he'll feel less isolated from the family and more comfortable with the new baby noises.
• Routine
  Consider whether your pet's walking, exercise, or feeding schedules will change, and adjust them now. Assume you will have less time for your pet after your baby is born, and decrease the number of hours you spend with your dog or cat in the weeks before you're due. Include in your adjusted schedule at least once a day, quality time for just you and your pet, with no competition for your attention. This "non-baby" time is very important for your pet and for you!
• Social Order
  Your position in the family's social order as the top-ranking animal in your family will be especially important as your baby's arrival approaches. When your position as leader of the family is secure and it's clear that the baby belongs to you, your pet should not challenge the baby's important rank in your home. A dog socializes in linear packs, which means it considers some family members as dominant to its own position and others as submissive. Initially, a dog probably sees the new baby in a lower pack order and may display dominant behavior. Watch for signs of aggression such as growling, ears down or laid back over the head, and crouching. Cats are less social than dogs and may choose to ignore the baby altogether. They do not socialize in packs, so they have little need to show aggression. For them, the most annoying part of living with children is being bothered, although some cats form very close bonds with their owners and may feel rejection. Both cats and dogs who form deep bonds with their owners may become depressed and may stop eating. If you observe aggressive behaviors in your pets, quickly correct them, but do not punish. Serious or lingering behavior problems should always be discussed with your veterinarian.
• Behavior
  Address any pet training and behavior problems. If cats have always had access to any surface in your home (counters, tables and so forth) you need to decide which places will be off-limits after the baby's arrival. Cats, especially, like curling up in the crib or bassinet. If your pet's behavior includes gentle nibbling, pouncing, or swatting at you and others, redirect that behavior to appropriate objects. Evaluate your dog's obedience training. If he doesn't respond to commands such as "Sit," "Stay," "Heel," and "No," can't walk obediently on a leash, has a jumping problem, or exhibits any aggressive behavior, seek professional help.
• Health
  Get your pet used to nail trims. Spay or neuter your pet. Not only do sterilized pets typically have fewer health problems associated with their reproductive systems, but they are also calmer and less likely to bite. Take your pet to the veterinarian for a routine health exam and necessary vaccinations.