According to the report made by a team of politicians and vets who have been working on saving lives of farm animals from the Fukushima no-go zone, all horses of 100 have been relocated to different parts of Japan. One organization that has been active in taking care of retired racing horses before the 3-11 Tsunami has taken in nearly 30 horses.
Is you visit here and click on date in calendar in the left column, you will find many photos of them. The carer who also manages the blog constantly uploads photos so a viewer can see how they are doing, including profiles for each horse. The horses look very well taken care of.