Toilet bowl kitties??? Well, it might be okay as long as you don't have any cleaners or disinfectants that dispense when you flush. I put the Clorox bleach tabs in the tank, so the bowl gets a fresh dose of bleach with each flush.
My son's cats must have the water in the sink in my grandson's bathroom left on a slow drip - even tho they always have fresh water in their bowl.
Cats!!!!!