I had a bitch do this not even a week from whelping, and it got pretty serious very quickly. She was spotting a large amount (6" round bright red blood spot on the blanket) 3-4 times a night, took her in to the vet and she was losing blood. Her pcv was going down daily for three days. The repro specialist, the emergency doctor, two internal medicine specialists, and the regular vet all recommended spaying her. I did an ultrasound, she had a large blood clot, the size of my palm, in her uterus, but the blood just kept coming. Had a surgeon do an exploratory on her, and it was determined to be subinvolution of the placental sites. This means the uterus was not clamping down, and the placental sites remained open and bleeding. We tried multiple oxytocin injections, and flushing her uterus with cold saline to potentially stop the bleeding, nothing worked, so I went ahead with the spay. Her uterus was huge and looked like raw hamburger after 5 days of bleeding. It caused problems with the co-breeder, but I don't regret spaying her, it saved her life.
The repro specialist did say that some bitches spot blood for up to 13 weeks, but in my case it was extreme and was a problem for the bitch. You just have to weigh each case, but saving the bitch's life in extreme situations is the way to go.
