wintermonths

I have a project to build an insulated doghouse for animal. I am having a hard time thinking of the material to use for the floor. This place can get muddy, wet, all kinds of conditions. My head goes straight to plywood and carpet, but I feel that will be torn up quick. It’s going to be like a cube size box with wall insulation and roof. I’m propping it up from the ground with 4x4 so the ground can get insulation as well, but what do I do for the inside? What should be use for the floor?

Any tips are helpful, but leave your own comments out about the cold weather and an animal. I’m trying to make the best out of a situation. Thank you.