Oh, Hell....let’s just have a wide open wild animal acquisition system in place. Let’s allow your neighbor to have as many she-lions, pumas, leopards, baboons, grizzlies and Siberian tigers as he or she wishes. No fences needed. After all, any law requiring fences or enclosures would be nanny stating to the max.
Zoos are already tightly regulated and no, you can’t just put a tiger in a dog pen in most places and call it a zoo. (You could in rural Mississippi, but I’d research any zoo there before going.)
And Siberian tigers became extinct many millennia ago.
Oops, that is saber tooth tiger.