Thanks, guys. I think I am going to make my own. I found one that was the size, but it was $80. Right now I'm planning on either a plastic base or a piece of wood. I'll glue a piece of vinyl floor to it and finish the edges (sand and paint). Then I'm going to put a PVC pipe frame around it so the dogs have to step into it. I can make whatever size I want bwahaha! And all I have to cut it the PVC which is pretty easy as Home Depot will cut the wood and a scrap piece of flooring. I'll go this weekend and get the supplies.
They make containers that are low sided, and fit under beds. Sort of like storage containers, but lower and longer. Maybe you could find one that the sides are not too high or if it is, you could cut an opening in one of the sides that the pup could go through. Hope this helps