Tom said additionally what I would have said, so not much to add, except:
1) fish with ulcers often don't float upon death. It depends in part on
amount of air left in bladder at death, plus extent (depth) of ulcer (esp.
if into peritoneum)
2) the fact that you can't catch the diseased fish is a good sign, in that
at least they have some strength to flee (although granted that is one of
the last things to go)
3) dips in small tank, etc are fine.
Here's another alternative I learned actually from Doc Johnson.. you can put
in an OG feeding tube (oral-gastric) using, for small Koi, a 6 French
(pediatric) tube, or go larger with larger Koi (up to 16 Fr or so)
Just like the intubation rule we use when tubing an adult patient (dia. of
5th fingernail), Koi have a marker for tube size as well! Use the dia. of
their pupil. Pick that dia. soft feeding tube and away you go!! OG
"intubation" is a piece of cake, but...
NB: There are 2 major caveats with using tubes:
1) insert back thru throat, making sure you don't insert off midline and
wind up exiting thru the gills! The esophagus is behind the teeth plate,
usually closed, but opens without a problem. As they have no stomach, their
is NO chance of regurgitation with this procedure, so no sedation is needed
(no folks I am NOT being cruel.. it's more cruel to use anesthesia when they
are very ill, as that may push them over the limit - death!)
2) instill your antibiotic (TC in this case), which you can mix as a paste,
by mixing a broken capsule/crushed tablet with castor oil. Instill NO MORE
THAN 2 - 3 cc maximum of the antibiotic/castor oil mix for each dose
administered, or you can perf. the intestines, esp. if they have not been
eating (which is why you may be doing this to begin with) and they are
contracted. Dose is a familiar 20mg/kg, so you need to estimate that. There
are charts to guesstimate weight from length, but here's a few points:
6" .05 - .1kg
10" .2kg
12' .3 - .4kg
16" .8 - 1.0kg
Good luck,
Greg


"Bob Adkins" wrote in message
...
On Sun, 08 Jun 2003 14:40:24 -0400, Jo Bohannon-Grant MD

wrote:

Which leads my to a stupid question: do all dead fish float?

Yes, they all eventually float.

An exception would be if the fish were partially eaten, opening the body
cavity.

Bob