Question
We have had the same goldfish in our pond now for about 11 years.  They were tiny little feeder fish that we saved I felt.  My question is now that they have grown large like koi do a  few of them have suddenly died.  They looked normal.  There are a few however that have a redness around their eyes and on their fins it almost looks like blood.  There are also a couple that have a bulge out eye now.  What is going on in my pond and how can I save my fish?  We lost one yesterday, and 3 today.

Answer
Bulging eyes are called popeye which is normally due to dropsy or other bacterial infections but rarely parasites or physical injury.  How big is your pond?  How big are the goldfish?  The red areas may be septicemia which is where the capillaries have burst.  This can occur from physical injuries (bruises from spawning or evading predators like herons), parasites, poor water quality, bacterial infections, and more.  Check your pond water's pH, ammonia, and nitrite to be sure they are okay.  Add some pond salt if you don't use that (0.05% if the pond has plants).  MelaFix may help a little as would a water change.  Could it be possible that the fish mass has now exceeded the size of the pond?  We don't always know for sure why fish die.  Koivet.com is a good site for goldfish and koi illnesses.  I lost 13 goldfish 2 years ago with NO symptoms at all, no reason that I ever found out.  They just were fine one day and dead the next, dying about one a day.  My water was fine, the other fish were fine, and I was totally perplexed.  I hope you can narrow down the problem and help the other fish.  Good luck!

Robyn
fishpondinfo.com