If it doesn't improve, metro. Granted this is with angels, but they usually act a little off long before stringy poo makes an appearance. I have one that was almost apathetic when it came to eating. He'd eat, but not with a lot of enthusiasm. And he was pretty much the same when it came to spawning/fry care. After the first dose, he turned into a jerk. Well, ok then. Still a lousy parent though. My daughter named him and his mate, "Dumb and Dumber".