hmm, maybe your dog has never been around horses. Maybe she is trying to get the minis to join in her play with her! We taught our dogs to be nice around the horses, and that horses are dangerous. Except that my (my sister in law's) dog loves to play with my special girl Cheyenne. Since Cheyenne was born, Radar, the dog, loved to play 'tag' with her. I know they play it very safely, and don't get too close to eachother to get hurt unless they are only walking or standing still. Maybe just let your new dog see the horses, and understand that they are ok, but are harmful, so that she doesnt try to be aggressive around them. Good luck! I hope she warms up soon, and I like it that you got a dog in need!