This is a bit of a mad thought but can you encourage a bitch into season if she's around an entire male dog. You know how some mares (mine!!!) will go into season if they think the boys are looking
That is so true s4sugar I have never known being with an entire male bring a bitch in season, I kept a stud dog with bitches and it didn't change their cycles. Would agree though that being with another bitch in season may well bring them in.