The normal gestation period in dogs is approximately 63 days from conception, although this can vary by several days. While this might seem like a straightforward answer, conception is often hard to determine. Sperm can live for several days inside the female, and eggs can remain fertile for up to 48 hours, which means the act of mating itself is not an exact measurement of gestation. This makes it hard to predict the length of pregnancy without the assistance of a veterinarian.
Hormone measurements give a much more exact time frame for gestation. Many breeders use vaginal smears and blood tests to monitor reproductive hormones during the breeding process. This helps them determine the best time to breed their bitch, as well as the length of gestation and the potential due date.
Gestation length according to accurate hormone measurements:
56-58 days from the first day of diestrus
64-66 days from the initial rise in progesterone
58-72 days from the first time the bitch allowed breeding
Pregnancy in dogs is relatively short compared to humans, about 9 weeks total, and each day matters. Knowing the length of the gestation period is important for the health of the pregnant bitch and the puppies and is used to monitor nutrition and veterinary care during pregnancy.
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