The estrous cycle of most female Goldens lasts 6-8 months, and some females have an estrous cycle that lasts 12 months, which is also considered to be physiological. The estrous cycle is divided into pre-estrus, estrus, late estrus and interestrus (resting period). The time from the start of blood discharge in the vagina to the acceptance of mating is the pre-estrus period, which lasts 7-13 days. The time when a female receives mating is the estrus period, which lasts from 3 to 21 days, with an average of about 9 days.
