Maîtresse Cathie La Divine - Update: I have not talked with her in a long time but did locate the images she sent to me and have added them here in my comments window.  It is still my hopes to someday be her horse to ride.

Although there isn't much about pony play on her web site, she did send me a photo of her doing pony play with a client on all fours.  I am sure that if I ever have a chance to be her horse that it will be a very realistic and enduring experience. 

I get the feeling she would put her all into her enjoyment of her horse and that there would be no thought toward my "human" form and I would only be her horse.  I do hope I get a chance to be her horse someday.  She also has other interests that I share.