By the summer, with her health issues under control, Polly's body steadily returned to a healthy weight, and her personality started to emerge as well.
"Polly has really started to show her character recently and has captured the hearts of all the staff at The Horse Trust," wrote her rescuers.
By August, six months after being rescued, Polly had put on 330 pounds. With her rehabilitation complete, she was finally set loose on the sanctuary's fields to run and play with the rest of the herd.
"It seems such a long time since Polly came to us in February. Hers was a case of cruelty of the worst kind. Her condition was so terrible that we could never be totally sure if she would pull through until recently," writes the Trust.
"It won't be the end of treatment for her, but it is the beginning of her new life."