Hi I have been divorced for about a year and my X has my horse he is registered in my name only there is nothing in the divorce about the horses .

If there is nothing in your divorce decree about your horse or what happens to it, that is sort of a major problem at this point for you.  You will need to file a motion with the court under s. 767.125 (failure of an asset to be disclosed) or s. 806.07, motion to reopen order or judgment for leaving out of the divorce judgment, which party is awarded the horse.