Help-have pics

[Koiamania]

Can you tell me what this is? I think a bacterial disease. Do I need to treat my entire pond. I got him about 6 weeks ago. He never seemed quite right-never came to the top to feed(now I know why-it must have hurt).

[Russell Peters]

It could be that it came with a bacterial infection. I would check all of your other Koi.

[Koiamania]

so is it definitely bacterial? Could it be a form of cancer? Who on this forum can elaborate? TIA

[MikeM]

I cannot say 100%. That is not an uncommon location for ulcer disease to set in, although abdominal ulcers are more typical.

As Russ suggests, you should carefully examine all of your fish. If none show any problems, then focusing on water quality is all you need to do right now.

[CarolinaGirl]

It may have started with a small injury and it became infected, eating away at the tissues. You can't treat your whole pond for bacteria without destroying the good bacteria in your filter. All you can really do at this point is make sure your water and pond are VERY clean. buy this, I mean NO mulm, leaves, or any other debris in the bottom. No gunk in the filters (clean the filters with pond water or dechlorinated water), no rotting plants anywhere. You need to eliminate all places where bacteria can multiply. Also, net the other fish and check them out. Often uncers start on their bellies so you cant see them without looking under them. If catching them is not possible and your water is clear, then get a mirror and put it on the pond bottom in the area where they feed. When you feed them, you can get a good look at their bellies in the mirror.

[JasPR]

Good advice , CG.

You can also bag the fish and hold the bag up and examine each fish's belly. You could also invest in an underwater video camera?

This fish was just unlucky. The infected area actually looks healed and non-active. This fish might have died from complications as the floor of a koi's mouth is very very important in transporting water across the gills so that the fish may gain oxygen and release metabolites from it's body. Without that ability to regulate water pressure in a closed mouth, the function must suffer. -JR

[HEADACHE6]

The location of that is the Main reason I hand feed my koi once a week .

They get a good meal , I get a good peek !

[Eugeneg]

Quote: Originally Posted by Russell Peters It could be that it came with a bacterial infection. I would check all of your other Koi.

In a situation like this koi I would kill it . Had it been a high quality koi I would quarantine and try Batril injections .
One has to take utmost care when grtting new fish in even from a reputable deeler . Sometimes these free fish could prove very expensive so one has to make sure that they are healthy and quarantined
Regards
Eugene

[Koiamania]

Thanks for all the advice. All the other Koi seem to be fine. Eugene, the koi was dead if you couldn't tell from the photo.

[lildude]

Is it possible that this ulcer may have started inside the mouth?