http://www.rendaivu.com/

"What is Rendaivu?
Rendaivu is a free software application that enables people to manage
their equine activities online. It is intended to bring equine
enthusiasts together to a common place where they can manage their
horses, organizations, riding schedules, business and advertisement
listings, and to find and meet new friends."

"Manage
Keep track of your horse records (training, showing, racing,
reproduction, and health). Join your stable, club/team, or
association and take advantage of the lesson, feeding, farrier, and
other schedules."

Maybe useful? The only problem I see is that it's
hosted on their site rather than you downloading software to you computer.