I have Finn, my pond frog since 2 yrs ago when he was a tadpole. The last few days he's been lethargic and now he's floating on his back, baring his spotted belly. He's still breathing... it doesn't look good at all. Should I just leave him alone? Let nature takes it's course? I feel bad for him, but I don't know what to do, or not do. Is this just natural for him? poor guy.