Quote Originally Posted by tonibun View Post
Cardboard is ok if the bunny doesn't eat it. Some do, some don't. Pets at Home do a fabric tunnel which is safer than plastic or you can find them on line under Cat's toys.
this is the key point, none of my previous bunnies ate cardboard. But Frosty does, and it caused a major gut slowdown, so they don’t get cardboard anymore.