How do you unlock the fields in paws and claws pet vet for your horse

You have to get a patch thing off the internet for it or it doesn't work.

Extended by Amyzone:

If you don't know where it is, then maybe I can help you?
http://www.valusoftsupport.com/KBArticle.asp?kbid=5399


PLEASE NOTE: This patch does not let you open your saved games. You will have to start a new game!