How do you tell if a cockatiel has a broken leg?

first of all what has he done to his leg? If it is seriou, he needs to see a vet. A vet will probably prescribe him with some painkillers. Just make you pamper him and when you are cuddling him, stroke his leg and see how much it seems to be hirting him. He might just need a bit of TCL! Our COCKATIEL WAS FINE AFTER A BIT OF FUSS!