A mother dog's body goes through a major transition in a very short time with pregnancy, labor and delivery all in the space of 63 days. After she whelps a litter, her behavior will change several times as she learns to care for and then wean her pups. A well-socialized mom is less likely to display extreme behavioral changes.
After Whelping
For a first-time mother dog, the appearance of multiple little charges can trigger a range of emotions and therefore, behaviors. If she is a family pet, expect her to ignore you in favor of the new arrivals. She may not want to leave her puppies, even to eat or go outside. When she does leave them, she will immediately return to the box. She is the puppies' sole source of nourishment for the first few weeks of their lives, and they will nurse at least every two hours.
Protective Instinct
Nature triggers a strong protective instinct in a mother dog. She may become quite possessive about her puppies and snap at people or other dogs who come near. For the first few weeks, give her space with her puppies in a quiet area and keep other pets, children and strangers away from the whelping box. Once the puppies are older, after 4 weeks of age, visitors can help to socialize the pups. By then, Mama will be willing to relinquish them to people.
Training the Pups
When the puppies are between 3 and 4 weeks of age, your mother dog may become reluctant to return to the whelping box or pen. She will start to teach her puppies independence, and she is beginning the weaning process. When the puppies jump on her and tumble over her, she may nip at them or push them with her nose. The puppies will begin to interact more with each other as they play. Most mother dogs will happily spend time with their humans again at this point.
Other Behaviors
Some mother dogs will have accidents in the house in the first week or so after giving birth, because they are reluctant to leave their pups. Take her outside, on a leash if necessary, for bathroom breaks until she's willing to go out on her own. Occasionally, mother dogs will try to move their puppies in an attempt to hide them from predators. Provide a quiet, safe place in your house for the new family. Use child-proof gates or an ex-pen to contain the brood. Covering the top of the pen with a light sheet can help provide a sense of security for the mother dog.