20/20 hindsight is always nice.  I'm not sure what I would do until I was in that situation.  But I do know living with animals, loving them as part of the family and part of being a responsible pet owner I would leave with them.  I think the problem with Katrina is that they didn't evacuate in time, look at Gustav 2 million people evacuated before the storm hit!  Wow.  None of the help came for Katrina until afterwards.