Curvature of spine

[pondboy]

Can anyone advise me why three of my large golden orfe have over the last three years developed a curved spine making swimming difficult. The spine becomes 'S' shaped, and the fish eventually die. Is this an age problem?
Also several of my large plump common goldfish are turning white from a bright reddish gold. They are otherwise quite healthy and feed well. Thanks in advance. Pondboyrofile:

 

[popeye]

hi pond boy
i have had the same problem with an orf developing a curved spine he did well though and grew quite big
but im afraid in time he got that he couldnt swim and so couldnt eat so i had to do the dastardly deed which was a first for me and i hope the last time.
i was told by a seasoned koi keeper that it would have been due to a chemical that it had come in contact with ,probably before i got it
so theres nothing that you can do about it
hope this is of help
popeye