sounds like a job for "pish pads" They are absorbent washable potty pads that have a waterproof backing snd csn be cut to fit any size or shape. I use them in my x-pen when I have babies and also take them with me to use in hotel rooms when we take the dogs with us. I use them both for potty pads and under thier bowls to keep it clean.
Here is a link:
http://www.pishpad.com/