that's why i don't buy nice beds for my boys anymore. I think since I've had them they've gone through 6 beds already (not to mention my own queen size one)! I got them one of those orthopedic beds from Cesar Milan...cost me a freakin' small fortune, and just a couple days later...ripped, torn to shreds. I know Cesar would've probably said "it's not what they're eating, it's what's eating them", or something like that, but i had enough and just got them two cheap crate pads at Target and no more beds. (Boy, felt good to get all that off my chest)!
Sorry i couldn't be of more help!