KHV Outbreak in Japan

[hoseki]

Unfortunate incidents occurred in the koi industry

During last winter, Koi Herpesvirus (KHV) was confirmed at several Koi breeders in Japan. Miserably, Virus was spread and outbreaks were also been reported in other countries. Some of the hobbyists and dealers from Europe and the USA suffered high mortality of their collections. Even worse, it is an ongoing event.
Japanese breeders and worldwide dealers are taking actions accordingly to prevent further damages. As spring is just around the corner, we need to be extra vigilant in 2019.

What is KHV?

Koi Herpesvirus (also known as Cyprinid Herpesvirus 3; CyHV3) is classified as a double-stranded DNA virus belonging to the family Alloherpesviridae (which includes fish Herpesviruses). This virus is one of the deadliest diseases in the koi industry. It is highly contagious, and mortality may begin very rapidly in an infected pond. 80 to 100 percent of Koi populations exposed to the virus usually may die within days when water temperatures are between 16°C to 25°C (60°F to 77°F). Any survivors may remain as KHV carriers for life and should be euthanized to avoid further infections.

In order to trigger the virus outbreaks, the water temperatures have to be within an optimum range; and koi need to be under stress. There also may be an incubation period of 7 to 21 days depending on the temperature. Infected koi may not show any clinical signs of disease if either of the conditions is not met. This means that the virus may reside dormant in tissues until the environment is right for them to activate.
Unusually, there were also cases reported with low mortality even the tests came back positive for KHV.
For more information, please read this article from the University of Florida's website on Koi Herpesvirus Disease (KHVD)
https://edis.ifas.ufl.edu/vm113

Test it! Do not guess!

The only way you can confirm is to have it tested. Do not guess when you find abnormal losses in the population. Please start by first contacting your local veterinarian if a test is needed.
Recent KHV Outbreaks in Japan
In the winter of 2018, a handful of breeders in Japan were confirmed with positive results:
- Tazawa Koi Farm
- NNBC
- Yamacho Koi Farm (Aka Chogoro)
- Hoshikin Koi Farm
- Marujyu Koi Farm
- Taniguchi Koi Farm (Updated on 3/5/19)
Under the supervision of the governors, they euthanized all of their koi in the KHV-contaminated greenhouses and sterilized their facilities. It was a big hit to the breeders, given that all of the koi were raised with care. Nonetheless, it is necessary that the breeders exhibit due diligence. This practice not only protects the farms and customers but also sets a great example for the industry.

What Hoseki Koi & Pond is doing for Prevention of KHV?

As water temperatures slowly rise in the spring, we need to stay cautious as more outbreaks may emerge. The damage caused by KHV is huge financially and emotionally for all of the hobbyists, dealers and breeders.
To protect the safety of Hoseki Koi & Pond and our customers, we follow strict quarantine procedures; and we work closely with our dealer to start screening breeders in Japan (regardless of relationship).

Here are our measures for KHV prevention:

1. All koi will be routed through the States to perform KHV testing

Due to the rising risk of KHV outbreaks, we decided to have our koi tested in the States before they cross the border. It is no longer safe enough to solely rely on the breeders' tests in Japan. Thanks to our partner, Kodama Koi Farm, for investing in their own polymerase chain reaction (PCR) device. It is a diagnostic tool in virus detection which allows them to perform KHV testing on site. Nevertheless, test samples will still be submitted to USDA APHIS-approved laboratory for KHV testing.

By comparing to Canada, water temperature is always within an optimum range in Hawaii. It provides the perfect condition for an outbreak with the commuting stress. Clinical signs of KHV can be induced more rapidly if the virus does exist in any of the shipments. All of the new koi will be completely isolated by breeder for 30 days to ensure that the virus has enough time to break out. KHV usually breaks out within 2 weeks at their water temperature.

2. Completely separate and isolate all koi by breeder during the quarantine period
Despite the efforts our partner has made, it is our standard practise to completely isolate our koi by breeders in heated tanks during the quarantine period. This process allows us to minimize the damage caused by diseases and to identify the source if there is any.

3. Quarantine new koi for 30 days
We completely understand that all of the new koi has been quarantined in the State, but better safe than sorry. Do not skip your own quarantine under any circumstances! After all, it is you who can best protect your own koi. It also provides a period of time to rest the koi before they are shipped.

Vital questions to ask about KHV before buying koi

It is always important to ask KHV-related questions and understand the history of koi you are about to buy.
Please ask your koi dealer the following questions:

- Where did you (the dealer) get the koi from?
- Did your supplier have them tested for KHV? If so, what was the water temperature? How long did they quarantine them?
- Did you have the koi tested if they are bought directly from Japan? If so, what was the water temperature?

Caution – if the dealer says:
- "These Koi were only tested in Japan" - Please be cautious. Breeders do test their koi in Japan, but it is not safe enough to rely solely on their tests.
- "The water temperature was below 18°C (65 °F)" - KHV is most likely dormant and hard to detect.
- "The koi were quarantined less than 2 weeks" – Bear in mind that it takes about 2-3 weeks for KHV to break out after the water temperature goes over 18°C (65 °F).

Hoseki Koi & Pond's Commitment to KHV Prevention

To keep this hobby safe and enjoyable, the dealers play a key role in KHV prevention. At Hoseki Koi & Pond, we strive to provide top quality Japanese Koi to the hobbyists in Canada; moreover, we also commit to delivering safe koi so you can enjoy them with peace of mind.

[tanksalot360]

I remember this has happened in the past.
KHV is a recurring problem but I admire the farms that comply to proper control with euthanizing their prized stock. One day there should be a vaccine that can provide the heard immunity they deserve.
I know Israel (govt controlled fish farming/aquaculture) is not exporting.
I found this more recent notice (August 2017)
http://www.inspection.gc.ca/animals/aquatic-animals/notices-to-industry/2017-08-25/eng/1503605707023/1503605707408