I love hearing that Warwick is OP. He is my favorite jungler and with a good team I feel overpowered because I regularly go legendary. He can definitely be shut down though it is really reliant on Warwick's own team, not the enemy team.
Wriggles,
Mercury Treads.
Guardian Angel.
Burst that down.
I love to dive with this build and you can build him however you want after those 3 items.
CDR, Defensive or Offensive but even if you build him Defensive with the upgrade to his passive(the magic damage per hit) his damage isn't something you want to ignore.
I usually build him tankwick and I usually rock people.