So far, the only thing that has held up is the Kong treat ball (with the grooves on the outside). If I fill/pack it with kibble, he loves to roll and toss it around to get all the kibble out. If I fill it with yogurt and kibble and freeze it, he thinks he's won the ice cream lotto. He will bring it to me when it's empty, has had it for a year and has yet to destroy it. Nothing else has survived....Wubbas, puzzles, kong toys, "tuff" toys ... nothing.