It takes 1 to 2 weeks or longer for a female dog to go into estrus. Normally, a female dog goes into estrus twice a year, from March to May in spring and from September to November in autumn. When a female dog is in heat, she will have symptoms such as redness, swelling and bleeding of the vulva, loss of appetite, and bad temper. The owner needs to be patient in raising the female dog. The female dog can wear menstrual pants, which can effectively prevent the blood from staining other places, and can also prevent mating with male dogs. It is best not to mate when a female dog is in heat for the first time. At this time, the dog's development may not be complete, which may easily affect the body's health.