do dogs get periods

Female dogs do not get periods like humans, but they do go through a reproductive cycle called the heat cycle or estrus. During this cycle, female dogs may experience vaginal bleeding and discharge, but this is not menstruation in the human sense. The bleeding happens during the proestrus stage of the cycle, which typically lasts 2 to 4 weeks and occurs about every 6 to 12 months in adult female dogs. The blood discharge is a result of hormonal changes and increased blood flow in preparation for potential pregnancy, not the shedding of the uterine lining as in humans. Female dogs' heat cycles usually start around 6 to 12 months of age, depending on breed and size, and can continue regularly throughout their lives unless they are spayed. Spaying usually stops these cycles, although some bleeding may occur shortly after surgery due to hormonal changes.