Can you use dog training pads on the bottom of coropolast

We have a dog and two parrotts, we use the potty training pads in the bottom of the birds cage and simply roll up the seed and mess and replace a few times a week, its keeps a nice dry bottom since the bottom layer is waterproof and the top layer is very absorbent. I use that on the bottom of the pigs cage ontop of the coroplast and about 2 to 3 inches of carefresh on top. Just wanted to be sure it is okay for piggies. The pigs dont chew and dont seem to know anything is underneath because it is so thick. Thanks for your help. Any other ides would be great too. Heather