How long is a dog pregnant?

The average gestation in dogs is sixty-three days from ovulation, with a normal range of fifty-eight to sixty-eight days. That sixty-three-day figure is the anchor for everything on this page: enter the ovulation date if you know it, or the mating date if you do not, and the calculator gives the most likely due date and the full whelping window — the earliest likely day, the most likely day, and the latest likely day — plus the dates for the ultrasound and the puppy-count X-ray. Ovulation is the more accurate starting point, because mating can happen days before ovulation: sperm can survive in the bitch for several days, so a mating date can be up to a week earlier than the true start of pregnancy, which makes the window from a mating date wider and less certain.

The range matters because the exact day of whelping is not predictable to the day, even with a known ovulation date. Puppies born before day fifty-eight are premature and may not survive; puppies born after day sixty-eight are overdue, and the bitch needs veterinary attention. Most bitches whelp between days sixty and sixty-five, and the signs that labour is near are well known: a drop in body temperature below thirty-seven degrees (normal is about thirty-eight to thirty-nine), restlessness, nesting, loss of appetite, and panting. Taking the bitch's temperature twice a day from day fifty-five onwards is the most reliable way to predict whelping — a sustained drop usually means labour will start within twelve to twenty-four hours.

What happens during pregnancy

For the first three weeks there is little to see: the embryos implant at about day eighteen to twenty, and the bitch may have a brief period of morning sickness at around three weeks. At about day twenty-five to thirty an ultrasound can confirm the pregnancy and check for heartbeats, though it cannot reliably count the puppies. The bitch's abdomen starts to show at about five weeks, and her food needs increase from then on — by the last week she may need fifty percent more calories than usual, split into small, frequent meals because the puppies are pressing on her stomach. At about day forty-five an X-ray can count the puppies, because their skeletons have mineralised by then. The last week is the time to prepare the whelping box: a warm, quiet, draught-free place with clean bedding, where the bitch can nest and where you can watch without disturbing her.

Feeding and care during pregnancy

Do not change the food in the first five weeks — the bitch needs her normal diet, and overfeeding early in pregnancy causes unnecessary weight gain. From about week five, increase the food gradually, and switch to a puppy food or a food formulated for gestation and lactation, because those are higher in calories and calcium. After whelping, the bitch's calorie needs rise sharply — a nursing bitch with a large litter can need two to four times her normal intake — and she should have food and water available at all times. Calcium supplements should not be given during pregnancy unless your vet advises it: extra calcium during pregnancy can suppress the bitch's own calcium regulation and cause eclampsia, a dangerous drop in blood calcium after whelping.

Common mistakes

The most common mistake is counting from the mating date as if it were exact — it is not, and the due date from a mating can be a week out. The second is overfeeding early in pregnancy. The third is giving calcium supplements without veterinary advice. The fourth is not having a vet involved: a bitch should see a vet during pregnancy for a check-up, an ultrasound, and a plan for the whelping, especially if she is a breed prone to difficult births, such as Bulldogs, French Bulldogs or Chihuahuas. The fifth is being unprepared — have your vet's emergency number to hand, know the signs of trouble, and have a plan for getting to the vet at three in the morning.

When to see a vet — urgently

Call your vet immediately if the bitch goes past day sixty-eight, strains for more than thirty minutes without producing a puppy, has green or foul-smelling discharge, seems distressed or in pain, has a puppy stuck in the birth canal, or stops labour with puppies still inside. These are emergencies, and a delay can kill the bitch and the puppies. See your vet during pregnancy for the ultrasound at day twenty-five to thirty and the X-ray at day forty-five, and for a post-whelping check of the bitch and the puppies. For the puppies' first weeks, use the puppy age calculator, the puppy weight predictor and the feeding schedule generator.