I don't know if this is a bug with a fix coming or not, but after having my kitties sit so they would be good and not follow me, I could not longer get them to stand up! I freaked out and, fishing rod near by, threw it at them and, voila! I had hurt my kitty, but it was now standing! Hope this helps, and if anyone knows why this happens please let me know.
http://empireminecraft.com/threads/cat-guide-catch-hatch-breed-feed.4802/ It will be answered in here