Report an Animal

I have a mission to report an animal to the Zoo, and I don't know how to do that.

First of all, I've been looking at the pages of animals whose owners have been gone for two years or longer. Does that not count as not being taken care of? What does count?

Second of all, where is it that you can report them? I looked at the Zoo and at animals' pages and couldn't find any button to do so.

EDIT: I figured it out by myself, never mind.
EDIT 2: I still don't know how to report them, though. Could someone please tell me?