I would still consider wood.
Most of our house is hard wood. It's soft enough that no one will get really hurt falling.
It's pretty low maintenance, meaning I don't have to wet-mop it very often (if I don't want to
) since it hides the dirt well.
As far as the peeing goes, I can't imagine that there'd be *so* much to soak through the polyurethane coating and warp the wood.