Hi Miss Dizzywizzy
Have you tried
DogPages?
That's a superb rescue forum, with lots of representatives of rescues posting there every day.
It would be a lot easier to advise you if you told us a little bit more. Things like - how long have you had each dog and how old are they? Are either neutered? Are they vaccinated? Do either have any health problems? Whereabouts are you?
In the meantime, I'll move this to the behaviour board in case anyone can offer you some advice to help you keep your dog.
Take care
Kathy