Dog menstruation is not once a month. Normal dog menstruation occurs twice a year, from March to May in the spring and from September to November in the autumn. Each time lasts about two weeks; the dog’s vagina during menstruation Bloody secretions will remain, so you need to pay attention to the dog's hygiene to avoid bacterial infection.
Tips:
If you don’t want your dog to have children, it’s best to have the dog neutered before its estrus, which will be effective. Prevent some diseases and extend the life of your dog.