Generally, male dogs are not allowed to climb Golden Retrievers within 10 days after they are in estrus, because menstruation has not ended at this time. It is not until 12-13 days after menstruation begins to decrease that it is the best time for breeding. At this time Female dogs will no longer reject male dogs. However, there are also a very small number of female dogs with special physiques who will end menstruation within 5-6 days after going into estrus. Such dogs are suitable for breeding within the first 1-2 days. It is best to breed them once a day apart in order to improve their quality. Success rate.