Hi daxxh! I wanted to let you know that I found horses in a couple of books recently. I had declined to read The Nothing Girl and The Something Girl in the Frogmorton Farm series by Jodi Taylor (author of the Chronicles of St. Mary's time travel series), because from the synopses they appeared to be YA (it turns out they aren't). However, I'd gotten one of her St. Mary's short story collections, and it included a story set in the Frogmorton Farm series, which I enjoyed enough to spur me to read the two novels.

They involve an adult woman who had an awful childhood and early adulthood, and the mysterious magical horse which had appeared at her worst time to help her get through things (there is a large herd of these helpers or angels, who make an appearance to help people when they are in life-threatening distress). It sounds like it might be a bit saccharine, but it's not, and I really enjoyed the books.