Every time a dog menstruates, it lasts for about half a month. It comes twice a year, from March to May in spring and from September to November in autumn. There will be signs when a dog is menstruating, such as frequent licking of the reproductive organs, bleeding from the reproductive organs, and taking the initiative to approach male dogs. When the dog is menstruating, you need to pay attention to supplementing the dog's nutrition, keeping the private parts hygienic, and preventing infection. You can wear menstrual pants for your dog, which not only prevents menstrual blood from staining other places, but also prevents your dog from mating with other male dogs.