The best thing you can do is to cruise this site in the emergancy section...
As a starter... here are three examples of my betta's (I know whats wrong with them and they are being treated... I will let you know if you are right)
I just rescued a male betta from walmart who was put in a cup wit another male betta... hes really badly chewed up... what should I do???
I just rescued a betta from Walmart... his cup at walmart was really dirty and had algea in it... his fins are all curled up... whats wrong with him and how do I treat it?
I rescued a pretty female betta from Walmart, her fins are destroyed ad edged in black, she was floating on her sde when got her and she now has trouble swimming to the top of the tank...