Your dog will give you signs that she's finished giving birth, but the best way to discern that labor is over is by knowing in advance how many puppies to expect. Once they're all out, you don't have to worry -- on the other hand, if you know she was expecting a specific number but one or two haven't appeared, you know to call your vet.
Your vet can detect the number of puppies via an X-ray around the sixth week of her approximately eight-week pregnancy. This is when the fetuses' skeletons mineralize, or form structure. Ultrasounds won't be as accurate -- it's harder for the vet to count the puppies definitively. Once you know how many puppies to expect, you'll know when all have arrived. The system's not completely foolproof, as there's always the chance one puppy's skeleton might not have completely mineralized at the time of the X-ray.
Dog labor -- whelping -- has three stages. In the primary stage, which can last up to 24 hours, the dam stops eating and might become restless. She might nest, creating a site to give birth. Stage two is delivery. The mother begins straining, and the first puppy should arrive within a half-hour. If she's pushing hard and no puppy arrives after 30 minutes, contact the vet.
As each pup arrives, the mother typically licks off the membranes covering the baby's nose. If she doesn't do this, you must clear the nose or the puppy can suffocate.
Puppies arrive every half hour to hour, but it's not unusual for a dam to take a break of an hour or two between a few deliveries, especially with a large litter. However, if she fails to birth additional puppies within four hours and you know more are inside her, call your vet.
Delivery times vary according to the mother's experience, litter size, and breed. Breeds with slender heads usually have faster and easier deliveries than wider-headed canines. If you're not certain how many puppies your pet was carrying, her behavior may give you a clue that she's done with whelping. After the last puppy arrives, the new mother generally relaxes. Her straining is over, and puppy care begins. At this point, she'll start nursing her brood.
The dam will usually expel, and eat, placenta or afterbirth, not to be confused with the membranes covering the face, after each puppy emerges. Sometimes the afterbirth won't emerge immediately. If all or part of a puppy's placenta doesn't leave the uterus, it can have potentially fatal consequences. That's just one reason why your dog and the puppies should visit the vet within 48 hours after delivery.
Normally, a placenta passes within 15 minutes of each puppy's birth. Signs of a retained placenta include fever, appetite loss, lethargy, and green vulvular discharge. Your vet can give your dog an injection to stimulate uterine contractions to expel the placenta or its remnants. However, surgery, including spaying, is required to save extremely sick dogs.