you don't vacate an apartment and leave your animal behind, especially without food or water. both of my cats were strays that people just left behind when they moved out of my old apartment complex. that kind of behavior is just despicable, but at least my cats were left outside so they could rummage through the trash and hunt for food when they were abandoned!

i'd definitely do something with the cat that involves her previous owners never seeing her again. they do not have the sense necessary to care properly for an animal.