Is she in foal?
My dad's boss breeds racehorses, but he is a fool who should NOT be allowed to own horses.
Ok, rant over.
He is bringing all his racehorses to the property dad manages so he doesn't have to pay to keep them somewhere else. There was a broodmare in foal in one paddock, so he put an empty mare in with her so she wasn't by herself. He then brought out a 2yo colt, and a filly about the same age, and put them in the paddock WITH the broodmare and the empty mare until he could sort out a paddock for them! Now the empty mare wasn't in heat when the colt went in, but the next day when they went to get him out, she was. What do you think the chances of the mare being in foal are?