I bought the washable pee pads on amazon. They look like these :
http://www.amazon.com/NorthShore-Ch...=1438344307&sr=8-3&keywords=reusable+bed+pads
Re-usable actual puppy pads are available too. But i got the larger ones for a small dog that had to have surgery.
I haven't used the actual reusable puppy pads. I've been happy with the human bed pads. Liquids don't soak through them.
They're also very sturdy. I wash them in hot water many times a week and they dont show a bit of wear or performance loss.
PS- You can probably find them at a local hospital supply company, too.