How long does it take for a dog to menstruate after giving birth is a relatively complicated question, because each dog's physical condition and menstrual cycle are different. Typically, a dog's first estrus (i.e., "menstruation") occurs around 6 to 8 months of age. However, after a dog gives birth, its menstrual cycle will be affected to a certain extent.

Some opinions believe that dogs will menstruate about 6 to 8 weeks after giving birth. However, please note that this time may vary depending on the dog's recovery and individual differences. In addition, there is also a view that female dogs will generally have a menstrual period six months to one year after giving birth.