Oh, and actually, the joke about bitches is that they will come in heat only if you hook them
Is that something like the bus comes when u light up a cigarette or?

Good post, you're right.
I've looked up medroxyprogesterone aswell but couldn't find anything it does with the hormones. More like it breaks/blocks the ovulation and prevents semen from entering the uterus. It can/will stop the bitch from coming into heat, but in most cases only after 6 months. Side effects, sometimes "feeling weak". But that's to much of a risk indeed.

I guess there are no further options

thanks for the PM