There is the Gurps setting "Bunnies and Burrows".
Yesterday in my game store I saw an RPG called Harvester, from Troll Lord games: medieval anthropomorphic animals in a fantasy setting. Kind of Castles and Crusades ish.
There's an older game called Ironclaw: same concept, different mechanics.
If you felt like inflicting pain on yourself, you could do something with Teenage Mutant Ninja Turtles.
Do you mean, is there a Gazetteer for Redwall?
As far as I know, Brian Jacques has not sold those rights yet.