Sorry to hear about losing your koi. After dealing with a few problems
myself a few years back I found that 1) see a problem jump on it quick. 2)
If the problem appears to have gotten to the point where it won't be heal
by fall, put the fish down. Harsh, but saves a lot of worry and stress, and
I didn't put these ponds in to be constantly stressed out over them.

Actually, before #1, practice prevention. Water quality and low stocking
levels. ~ jan

On 10 Mar 2007 16:44:36 -0800, "scs0" wrote:

I isolated that koi from the others and then took it to the vet. Oh
what fun it is to transport a large fish to the vet. Anyway, they
took some samples of the fish's spots and had them analyzed. At the
office the vet was able to determine that there was a fungal infection
going on, but he sent the sample of the mass away to the University of
Florida to analysis. They reported that the fish had malignant
carcinoma and that there was nothing that could be done. This was
good news because the alternative was either carp pox or another viral
infection and both of those were contageous and uncurable. Cancer is
not. The fungal infection was probably the result of the fish having
a compromised immune system.

I found out all that information the day after the fish died. I had
it isolated in about 20 gallons of water until I found out what to do
next and was treating it for the fungal infection that I knew it
already had. The water was unfiltered so I would replace half the
water every day and had an aerator bubbling in the water 24/7 and
during the daylight hours a second solar air bubbler kicked in. He
was even eating, but one day I went out to do the daily ritual and as
soon as I took the lid off the container it started to rain. I left
and forgot to put the lid back on which meant the airbubbler wasn't
bubbling in the water. 2 and a half hours later, yes only two and a
half hours later I went out and the fish was dead. I'd like to blame
that on the disease, but that's just the stupid tender nature of koi.
And part of that time a light rain would have been splashing on the
surface! Oh well, it probably woudn't have lived much longer anyway.