As HK said, cats are confirmed, I believe Vattier (CDPR PR guy, I think) also said other animals will be in, potentially dogs and the like.
I don't think a lot more than this ^ will be in the game. Maybe rats, some street mutts and a cat or two. If it has flourishing wildlife it would totally go against the dystopian world they're trying to create. There is also supposed to be kind of a food shortage I think, and that wouldn't sit well with deer running around on sprawling hillsides either.
On the other hand that guy sat and ate ramen with an egg in it, I'm guessing that egg had to come from somewhere. It would be amazing to see like food factories in the game, just horrible inhumane produce plants with animals in cages and dodgy stuff being grown in laboratories and stuff.