A note on diseases


Happy Koi takes our sale of live fish extremely seriously. We will never knowingly sell you a fish that is anything less than 100% healthy. In fact, we will keep a fish back if we are even vaguely suspicious about it.

You are not absolved from doing your own quarantining however. It is good Koi keeping practise and we expect that new fish will be quarantined as part and parcel of being a responsible pet owner.

Over the last ten years Happy Koi has not experienced KHV within our facilities. We are fanatical about our KHV testing regimen and our average quarantine period is no less than 8 weeks. Our new quarantine facilities are specifically designed to ensure sufficiently high water temperatures and stress tests to induce KHV if it is present.

Consider the cost of a single KHV positive fish bought from some backyard operation. It is not the cost of the fish, it is the cost of your entire collection. More on this below.

Be safe. Buy from reputable dealers that have excellent track records. Ours speaks for itself.


KHV (Koi Herpes Virus) specifically

You need to understand the following. It is not good news and it is very serious indeed.

1. KHV is the most serious disease ever to face the Koi hobby.

2. It is 100% lethal. Survivors should be euthanased as they become carriers.

3. It is pervasive and easy to spread - a simple water splash will do the trick when the virus is active. 

4. KHV has two states, active and inactive. When active the infected fish sheds a massive virus load into the pond water.

5. It is undetectable when not active (i.e. latent).

6. It is undetectable in carrier Koi.

7. KHV can only be detected when active. - i.e when it's already too late.

8. The rules of thumb are that KHV activates when the water temperature is consistently above 22 Celsius. Fish stress helps trigger KHV activation. Symptoms will manifest in 10 to 14 days should the virus activate.

9. Koi will become slimy, with sunken eyes, gill damage. The immune system is wiped out allowing parasites to take over - often the parasites are mis diagnosed as the cause of death. Between 80% and 90% of the Koi population will die within three weeks of the disease outbreak in most cases. Some have less, some have more but the nett result is an effective 100% fish kill.

10. A specific test has to be carried out for when KHV is suspected. This is done by MDS in Durban.


KHV is a dread disease. It is called the Koi Herpes Virus and it is 100% fatal. Fish that survive an epidemic of KHV become carriers of the disease and pose a direct and lethal threat to any Koi that they may be exposed to at any time in the future.As such survivors of a KHV outbreak sadly must be euthanased.

KHV is extremely dangerous because of its dormancy characterstics. It cannot be tested for if the virus is dormant within a Koi. The presence of the disease can only be confirmed once the virus is active and the fish are all doomed in any event. It is a bit like having a massive car accident only to have the paramedics arrive to tell you you've just had a massive car accident and that you have minutes left to live.

KHV is as serious as a car wreck. KHV has spread through collections throughout the country thanks to the vow of silence that follows the disease. The implications of KHV are extraordinary. Tracing and proving a source is fraught with danger for anyone who has unwittingly spread the disease through ignorance, and for Koi dealers who may have supplied KHV positive fish.


What you can do about KHV

If you get KHV, sadly the best thing is to euthanase humanely and quickly.  The next best thing is make it count for something.Tell us about it. The greatest weapon this disease has is the blanket of silence that surrounds it. For many reasons, not the least of which is the traceability of the disease (especially when confronted by the latency of the disease) people understandably choose to keep quiet about it.

However, by establishing individual events and histories a bigger picture of the disease can be formed. This really is the only way we can hope to eliminiate KHV and to identify weak points in how we contain it.

It is not your fault you have KHV. Sure, there will be emotions involved as we are dealing with pets and in some cases extraordinarily valuable pets. These are valid in their own right. But by keeping quiet and not letting people know about KHV you are contributing to it's silent spread. It is much like HIV in this regard.

Start with your dealer. Inform all the dealers you have dealt with in the past, even if you may not have bought fish from them. Tell people who have been in contatct with your pond - forewarned is forearmed. And whilst the Koi Society after ten years still has no official KHV response mechanism, inform them anyway.

And if you have ever bought fish from us, we would consider it a massive disservice and an abuse of our relationship NOT to inform us. Whilst we go to the furthest extremes to ensure we do not get KHV, it will be massively useful for us to know to be able to file the incident and build a picture over time. We're not infallible - no-one can claim to be when it comes to KHV - and the biggest secret to minimising the damage is to know as soon as possible in order to limit it as much as possible!