I Googled it and it said that if a bitch is around another bitch in heat, the hormones can kick in and this is for when pack dogs need help nursing pups, both mothers can do the job. It should resolve in 3 weeks, but the Allie can get a bit anxious due to no pups. Too bad you cant find her a little orphan to nurse.
ALso a female can be breed and have a + test and go just like she is going to have pups and nothing. they will bag up and nest also but no babies we women van have them to and it can be a "hydataform mole" in the uterus