I am not sure if Koi are susceptible, but in freshwater aquariums, there is a disease
called Popeye, where the eyes bulge from their sockets. I treated mine with Maracyn, and
Maracyn-Two, and MarOxy, concurrently. It is my understanding that it is a build up of
fluids caused by an infection of some type, and possibly not always the same infection.

Perhaps you could quarantine the Koi in an aquarium, and try using the meds on him.

Good luck, if it is Popeye, it isn't an easy one to beat.

--
DeAnna

Drop "BYE" to email me.

"Keith and Wendy Slonecker" wrote in message
...
Jan:

Thanks. I have not added any new fish in the past 18 months.

The water temp is up to 54 degrees right now so I just dosed the pond with
another 60 ml of Koizyme, hoping it still might be beneficial in case of
bacterial problem. In the last 12 hours the sick fish seems to be a little
more active and is not hanging at the surface and not hiding either. Its
just swimming slowly, kind of with the rest of the gang.

wendy in Oregon