As reported by VetInfo, mother dogs are capable of bleeding for up to 12 weeks after giving birth. The length of bleeding time varies by dog based on the time needed for postpartum healing. Once the uterus recovers from the detachment of the placenta, the dog should stop bleeding.
According to PetWave, blood is present in the mother's discharge, or lochia, which consists of tissue and various fluids. The color of lochia varies, but the liquid is odorless in a healthy dog. When the blood exhibits any odors, thickness or paling in color, the dog may have an infection and a vet should be consulted.