Sarasas Comet Tail Problem

[sarasas]

I have 8 sarasas comets in a pond which was built back in the summer. Since it was built only 1 fish has died and I couldnt see any problems with it. I have now just spotted a problem with the smallest fish and have taken it out and placed in a separete tank.I have looked at the tail fin closley and it actually feels hard at the end.The tail part has gone white and seems to hinder the fish when swimming.Apart from that teh fish is very active.I have tried to find something simular online but can only see fin rot
Does anyone have any ideas ?Thankyou

 

[The-Wolf]

as you say white and hard I'm thinking carp pox.
it is not life thretening and not contagious.
it is also untreatable.

 

[sarasas]

as you say white and hard I'm thinking carp pox.
it is not life thretening and not contagious.
it is also untreatable.

Thankyou for your advise on this,I will keep an eye on it .