There are so many diseases that can affect Koi fish, such as parasites, dropsy, sleeping disease, and many more. One of many dangerous disease that attacks Koi fish is the Koi Herpes Virus.

In this blog post, we will explain the History of the Koi Herpes Virus, the characteristics of fish affected by this virus, and the large cases that have occurred due to the Koi Herpes Virus.


Cyprinid herpesvirus 3 or better known as KHV (Koi Herpes Virus) is a species of virus that causes a highly contagious viral disease to the type of carp, Cyprinus carpio. This type of virus is most often found in koi fish, which are usually placed in outdoor ponds. The first KHV case was reported in 1998.

KHV is a DNA-based virus, after being identified KHV is included as a type of herpes virus. KHV remains with infected fish throughout their lives, making the recovered and exposed fish potentially become carriers of the virus. KHV-infected koi fish can die within the first 24-48 hours of exposure. This virus is found in 33 countries. One of them is Japan.


The characteristics of Koi fish affected by the KHV virus are as follows:

1. Koi fish often make movements that are not controlled, sometimes active and sometimes silent.

2. Fish often gasp and tend to rise to the surface.

3. Fish appetite decreases

4. Red and white spots appear on the gills, this is due to the presence of necrosis, namely the death of the gill tissue. Gills will paler and decay.

5. Often blisters occur on fish scales.

6. The eyes of the fish become slightly concave.

7. There is blistered skin.

8. Mass death of koi fish can last 1-5 days.


one of the biggest cases of the KHV virus has happened in Japan in 2018, where there were several farms that were attacked by the KHV virus until they had to destroy all the fish on the farm. Some of the farms affected by the KHV virus are Tazawa Koi Farm (Uonuma City), N.N.B.C. (Nagaoka City), Hoshikin Koi Farm (Ojiya City), Yamacho Koi Farm (Nagaoka City), and Marujyu Koi Farm (Nagaoka City).


Leave a Reply

Your email address will not be published. Required fields are marked *

2 × 5 =