When my mom was growing up she had a female dog that was in heat and my aunt who was about seven or eight had to take care of the dog along with my mom. When my aunt brought the dog inside she was cleaning it up when my aunt thought the dog had gotten injured and she panicked and told my grandmother and mom about it and that's when my mom knew about the discharge. I don't remember what my mom and grandmother did with the dog when she had discharge but from what Mom told me my grandmother put towels on the floor so the dog wouldn't have accidents. But they never took the dog to the vet when she went in heat because Grandma thought it was a normal thing and my mom had that dog for about two years but then according to my mom's story the dog ran away and never returned home. So try putting towels around your dog's areas and she won't have messy accidents