The fish below were KHV
confirmed at the UGA, University of Georgia,
in the summer of 2003. The fish, which
I bought as breeders from a new-to-me source
started getting sick and dying while I was
raising the temperature to check for KHV.
Since the spring of 2002 all incoming fish
are put through a series of raising and
lowering of the water temperature to check
for both KHV and SVC. This takes place
over a course of 3 to 4 weeks.
One unusual aspect of these fish is they
were parasite free. This was a bit
surprising because parasites are one, but no
means the only way, that KHV is
spread. While going through KHV in
1998, the first year that KHV hit the United
State en masse, costia was a factor in the
KHV.
"Scalded" which is what I refer to for lack
of a better word is symptom of KHV.
The area looks burned, is lighter in color
than the rest of the fish. The scalded
area has no slime coat and feels very rough
to the touch.
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The picture to the right shows the best
example of the "scalding" I refer to.
It is just in front of the dorsal area
on the back. |
 In some cases the
scales would
rub right off the fish with just a slight
pressure of handling the fish. Many
scales would be found in the net if one was
used. |
 Of
course there are other symptoms and these
include fish hanging in the water with the
head up and tail down, piping at the
surface. The piping is actually the
fish breathing hard because the damaged
gills can not take in enough oxygen. Some
fish may lay on the bottom but most of the
ones in the tank with KHV did just the
opposite. Once the scalding appeared
and it seemed to co-inside with the hanging
in the water with the head up and tail down,
the fish generally died with 24 hours.
The fish stops eating, will not eat.
The eyes sink into the head and take on a
hollow appearance.
 This
is an actual
picture of the gill on
a KHV infected fish
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In
most cases the fish was fearless and
listless and could be easily picked up in
your hand with no fighting or swimming away.
Nor did the fish flop and try to get away
from your hand as a healthy fish would do.
Although
the picture to the left is of gill damage
caused by chilodonella, this is the type of
damage one will see with KHV also.
Healthy gill |
Of the 200 fish there were 10 survivors in
the same tank that showed no symptoms.
In fact those 10 continued to eat and
thrive. Once the testing came back
positive from UGA, those 10 fish were
euthanatized. Heavy bleach was run
through the tank, filters and pumps.
All nets, bowls and pails that came in
contact with the fish were put in the tank
at the same time to be sterilized.
In summary, this could have been a disaster
for us personally. What saved the rest
of our fish is the fact that each tank has
its own bowl, net and pail, and we wash our
hands thoroughly after working in the tank
or handling the fish. No other fish on
the premises was contaminated by KHV.
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