How long can a koi suffering from internal infections live?

[SimonW]

Hello friends:

I moved my small koi indoors for 1 week ago, and one of them seemed to have a internal infection: Redness and some swelling between scales on its belly, and its eyes were bulging out. It had been 10-12 centigrade for 2 weeks.

The indoor temperature has been about 20 centigrade. After it had been indoors for 1 week its eyes are no longer bulging, and the swelling belly has receded. But there is still redness between the scales on its belly. It has good appetite and has no other symptoms.

Can I be quite sure that it is recovering? Thanks for your thoughts!

[richtoybox]

Maintain excellent water with zero values for ammonia and nitrite and a constant pH, morning to evening, and there is a chance that the fishes immune system will heal the fish. It sounds like it has started healing if the eyes are no longer bulging and the scales are noticeably laying back down. Water quality is critical at times like this with as close to zero changes causing stress as stress leads to worsening health. You might try to use a triple antibiotic ointment rubbed on a dry skin area with the reddened scales, but I would wait and see if the fish continues to improve. If it were worsening, to answer your question on lifespan, it would not last very long without antibiotics.

[SimonW]

This fish is still happily alive with great appetite.

When I looked at it more closely I found that the "internal infection" may be varicose veins, though it has bulging eyes earlier. Or the internal infection was healed but not 100% recovered, leaving the varicose veins. What do you experienced koipheners think? I noticed the veins on its face already for maybe 1 year ago.

Quite good-looking from above, but disturbing from side. I wonder if you would keep it?

[richtoybox]

I would just keep an eye on it. It could be just large veins and nothing to worry about except cosmetics. The decision to keep or move a fish is a personal decision but if from above it is a looker, I would be more tempted to keep. It might not be the best show candidate, but very few fish are.

[mark76ac]

It's a good sign that the koi's eyes are no longer bulging and the swelling has receded, especially since it has a good appetite and no other symptoms. However, the redness between the scales indicates it might still be recovering from the infection. Continue to monitor its condition and maintain a stable indoor temperature.