Dogs go into labor when it is time to have their puppies. The labor process includes the first stage, where uterine contractions begin; hard labor, in which the puppies are born; and the final stage in which the mother dog passes the placenta and afterbirth. Normally, puppies are born 45 to 60 minutes apart.
Owners can tell when their female is about to enter labor when her temperature drops below 100 degrees Fahrenheit. The first stage of labor can last anywhere from 6 to 12 hours. Only when she is fully dilated will the puppies begin to emerge.
During the second stage of labor, the puppies are born. Puppies are born in a membrane that the mother dog will clean off the puppy.
In a healthy delivery, the final stage of labor will involve the delivery of the placentas and afterbirth. There should be one placenta for each puppy born.