goldfish with huge growths

Question
Dear Sir,
I purchased some 2 year old fish last year from a garden centre in Newhaven in sussex, a lot of them died within a few days, which I have found is normal, but one of them has a  large growth on its side, and getting bigger, any idea's ?. a similar thing happened to me a long time ago, the growth burst, fish died, and then my entire stock of fish was wiped out by something. Had to drain pond and treat remaining water with rock salt, pounds of it.Don't know wether to kill fish as another one has now got one of these lumps coming on its head.Both Fish seem fine and feeding well. I really do not know what to do, do not want to loose my stock of breeding fish. Any advice would be welcome.

Many thanks

Mike

Answer
It's not normal for fish to die.  It is common unfortunately.  What does the growth look like?  What is the color, size, shape, etc.?  Growths can be parasites, tumors, cysts, fish tuberculosis, infections, etc.  It is best to quarantine fish but even then sometimes something gets into a pond.  Could you send photos of the problem to help at fishpondinfo.com for me to look at?  A picture will tell me much more.

Good luck!

Female Robyn Rhudy
fishpondinfo.com