Your name, horse's name. Age. Emergency contact number. GP name and number. Any medical history. (Your's not the horse!)
You can go into a bit of an essay if you need to on the inside. If you've got any allergies or something someone needs to know immeidately then put it on the front bit of the sheet so they don't have to get the card out to find out what you're allergic to or whatever. If you carry a medalert tag you can reproduce the casuceus (how do you spell that?) on the card so someone will know to look.
