The apparent gestation period for bitches averages 63 days with a range of 56-72 days if calculated
from the first mating. This large variation is mainly due to the long and variable oestrus period
(season) of the bitch, and the long lifespan of eggs and sperm. If we measure progesterone during the
bitch's season, it becomes much easier to accurately determine when she will give birth, as it is 63
days after ovulation (with a day either side as the range!). Please talk to us about measuring
progesterone if you wish to get your bitch pregnant; it is a useful tool not only for determining when
she will give birth, but also when to mate her for the best chance of a successful outcome.
