SimGuruHydra has posted up a thread in Technical regarding Horses & Graphical Issues. She explains how to make sure your Computer & Graphics Card is up to date if you are experiencing any issues.
Seems they forget to add a 2nd part of what you should do or expect from EA if you are up to date and this is not a PC related problem. I also find it odd that this isn’t stickied in the Pets forum. After all Pets is the reason for all these issues. 😛