I also agree that your neighbor shouldn't have any animals at all since she doesn't know how to properly care for them. These kind of people make me so mad. It's like they don't even realise that the cat or dog they adopted is a living thing that relies on it's owner for food, water, medical attention, and proper care. You are doing the right thing by caring for this sweet cat and hopefully you can improve his quality of life and either give or find him a loving and caring home. Good luck and please keep us updated about your progress.