Dogs typically bleed for about 7 to 10 days when they are in heat, which is roughly half of their entire heat cycle that lasts about 2 to 4 weeks (14 to 21 days)
. The bleeding occurs mainly during the proestrus stage, the beginning of the heat cycle, when the vulva swells and blood-tinged discharge is noticeable. During the next stage, estrus, the bleeding usually lessens or stops, and the dog becomes receptive to mating
. The amount of bleeding can vary significantly between individual dogs; some may bleed heavily while others have very light or barely noticeable bleeding, often influenced by the dog's size and grooming habits
. In summary:
- Bleeding duration: about 7 to 10 days
- Total heat cycle length: about 2 to 4 weeks (14 to 21 days)
- Bleeding mainly during proestrus (first 7-10 days)
- Bleeding lessens or stops during estrus (next 5-10 days)
This pattern is typical but can vary by dog breed, size, and individual differences
