Hi, I must be doing the same course as you because I'm on the same question. (Physical and psychological reasons not already listed) Physical reason she won't mate.
At the start of her heat when she's in pro-oestrus she will attract dogs and show interest but she will not allow any to mate with her at this time.
The psychological reason I'm stuck on as well, hope I helped a little. Good luck.
At the start of her heat when she's in pro-oestrus she will attract dogs and show interest but she will not allow any to mate with her at this time.
The psychological reason I'm stuck on as well, hope I helped a little. Good luck.