You would have to let us know what, if any mods you had loaded. If you have none then I would suggest running a repair. Let me know what you have and I'll see what we can do to assist. :D
http://www.laymark.com/l/c/c48.gif my ninja kitty took a chunk outta me yesterday and although it bled like blazes and hurt like hell I sprayed a load of antiseptic on it and the accompanying scratches and it seems ok. Leg not fallen off or anything at any rate :D