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- Pregnancy Week by Week
Pregnancy Week by Week
The length of gestation, and therefore the date of whelping, is determined by the date of ovulation which we have named DAY 0.
In fact, there is normally some degree of uncertainly regarding the date of ovulation, which is difficult to identify without precise monitoring of heat by a vet.
My bitch accepts the male
If your bitch becomes receptive to the male, it means that her body is secreting sufficient hormones to stimulate ovulation and that she finds the male acceptable. He will thus be able to cover her.
Mating is preceded by a courting phase during which they play, but penetration can occur rapidly, in under a minute. There can however be a number of attempts particularly if the partners are lacking in experience.
The male mounts the bitch and penetrates her, generating a vaginal reflex in the bitch which traps the male until the act of mating is complete.
This lock phenomenon, that keeps the two dogs locked together for 15 to 30 minutes on average, can seem even stranger if the male does a 180° turn, which is more often than not the case.
The two partners thus find themselves with their respective hind quarters stuck together, each dog facing the opposite direction.
It is vital not to try separating them as this could cause a haemorrhage or a tear.
Above all, do not spray them with water in an attempt to interrupt mating.
Mating can be repeated two days later
The mating process does not necessarily mean that fertilisation has occurred.
Mating might have taken place at a time when the bitch’s fertility had not yet reached its peak. Of course, the sperm can survive in the uterus for up to 7 days and fertilisation can therefore take place several days after mating. To increase chances, however, mating can be repeated once after a two day interval.
The sperm reach the ovum
Gestation begins when the female’s ova are fertilised by the male spermatozoa.
This fertilisation gives rise to a fertilised egg of which half of the genetic heritage stems from the father’s chromosomes and half from the mother’s chromosomes. This egg is the first component of a new living being, first of all an embryo until the 35th day of gestation and then a foetus and future puppy in the final third of gestation.
Whatever the breed, gestation lasts on average 63 days in the bitch, when you count the duration between the day of ovulation and the day of whelping. This can vary between 56 to 70 days, if we are not precisely aware of the day of ovulation, as the egg can have been fertilised immediately or several days after the introduction of the spermatozoa at mating.
The embryos are afloat in the uterus
Towards the end of the first week following fertilisation, the embryos, which are formed very high up in the uterus, will migrate towards the uterine horns. They then float and move around within the uterine liquid.