hI there ! It seems I'm always trying to save pet store fish that are in trouble .. when I see them I just can't leave them . Tonight I seen a white koi in a tank , very bent and havifn a hard time , being attacked by a large koi .. I could not leave him to die that so way now he's home .. question is I think he may have internal parasites so I treated him in my 1 gallon hospital tank with parasite guard , prime and stress coat added to the water. Later u came back to find a small whiteish looking worm ( or at least what I think is a worm ) on the bottom of tank .. Am I on the right course with him? can he b saved at this point? Do parasites cause a fish to be bent?