For mating, the female is usually carried by the male as soon as the disappearance of the blood flow from the vulva is noticed.
Before mating, sometimes the male initiates a rather long courtship rite while in most cases he just licks the female dog's vulva before mounting her.
If the female is in heat, she will be available to the male by keeping firm and moving her tail sideways to reveal the vulva. After a few minutes of courtship, the two dogs will join in "a long hug" which can last up to an hour. At this moment, intense thrusting movements and sperm ejaculation are associated: at the end of the thrusts the two dogs remain fixed, ejaculation continues, which is in this phase very rich in sperm.
After mating, the heat does not end even if fertilization has taken place: for this reason it is better to isolate the female so as not to risk the birth of puppies from two different fathers.
The pregnancy should start after the first heat, at about one year of age of the female dog.
Not pregnant female dog
If the female dog has not been covered or has not become pregnant, about 6 months later she will return to heat: this cycle will be repeated constantly and punctually throughout her life, since the canine species is free from menopause even if there is a certain reproductive involution with advancing age.