Assess Viral Pathogens

For the purposes of this article, I would only address Koi Herpes Virus. No other virus is going to kill any appreciable amount of fish. Even with viruses like Spring Viremia of Carp, we won’t see losses higher than ten percent. But with KHV (Koi Herpes Virus) we will see monstrous losses. Here’s the breakdown that should make you suspicious:

1. Water quality checks out well (use your tests) but the fish skin is peeling.

2. Gills are breaking down with rotten looking patches.

3. Fish develop black rings on their skins

4. The disease started when the water hit 67^o Fahrenheit

5. The deaths really got rolling at 74^o Fahrenheit.

6. New fish without quarantine are in the history, almost always from Taiwan, Hong Kong, or Thailand.

Go To Step Eighteen

Supplemental Reading:

Koi Herpes Virus - What To Do After Infection - This article describes KHV and then tells you about some folks who are adopting Koi who survive KHV instead of leaving you to kill these amazing but probably infectious fish. By Dr. Erik Johnson

Koi Herpes Virus - KHV - More advanced information including more on control of this virus and limiting infection - Article by Dr Erik Johnson