If you use any of this information, I request you give credit for the origin of the Pictures and the article. 

Thank you...Walter Oldenburg

To download the story of our experiences with KHV...CLICK HERE!

The first group will show the damage done by KHV. The most consistent symptom was the gill damage. Every koi that died demonstrated some form of damage.

Symptoms varied among the Koi. Not all koi displayed the same external symptoms. Judge for yourself. Some shed excess mucus, some experienced scale loss with no ulcers, some had ulcers. On others they may have had sunken eyes, deformed head, veining in the body or fins. Some experienced loss of slime coat, scale loss and fin rot.

PCR Testing

DR. Helen Roberts suspected we might have contracted KHV due to the high moralities we we’re experiencing. She suggested we needed to get some samples and send them in for testing. This first test is a little gross; It’s called a Pcr test (polymerase chain reaction). This test is only successful if the koi happens to be actively shedding the virus or has just died from it. This technique amplifies the DNA of the virus making it easier isolate and detect. In our situation we brought a few dead koi to Dr. Roberts. She then removed the spleen, the kidney, took a sample of the gills and sent them to the University of Georgia. The test returned Positive.

Serology Test

This next test was to determine the condition of our remaining koi. The Serology is also termed a “Virus Neutralization Test.”  The serology looks for antibody production. It takes 2 to 3 weeks for the antibodies to develop after exposure to an infected koi. Testing before that time can result in a negative test. 

The serology is where blood is drawn and sent to a lab. This test can pick up the antibodies usually up to 1 year after contact. Our test was conducted by our favorite Vet DR. Helen Roberts who has been a great asset to us. The testing Lab was the University of Georgia. The results came back negative. We had her out to visit us recently, to test some our new koi before we introduce them to our herd. Fortunately the test came back negative. We thought it better to play it safe this time around.

Euthanizing

Euthanizing the remaining koi. Probably the hardest thing I had to do. Ever.... We had been enduring the effect of KHV from February 2006, to May of 2006. I can’t tell you how tiring this experience was to watch the koi die one at a time. We thought we’ve gone this far, let’s experiment with heating the koi to 90 degrees to see if it really makes the virus go away. It worked... for a month and 2 more koi died... so we figured let’s try it again. A month or so went by and we started to see the effects again. Tired and weary from this venture I said to Lin... We need to do this. Bravely holding back the tears she replied “do it when I’m not there”.

Additional Information

Cross Contamination DON’T BE TEMPTED!

Let's talk about cross contamination for starters. I can't tell you how many people receive koi from different sources and combine the koi in the same tank or pond. We had one in particular that we received from a dealer in Tennessee (he’s now in another state). After quarantining it for three weeks we placed him in our main tank with all our other imports. We noticed it's nose had a blemish so we took him out to treat him with 2 other koi who we're experiencing ulcers. We didn't know at the time that it was due to KHV exposure. We treated said koi and he was responding very well to the baytril treatments. Looking healthy we put him with our original koi. 3 days later Lin noticed him isolating itself with clamped fins. We put it back into the hospital tank. 1 week later it lost it's slime coat lost scales and his fins we're ragged. It died.

This one koi had only spent 3 days in the other tank. 2 weeks later after the virus had time to incubate within our original koi, they started showing symptoms. Our very first koi “Papa” was the first to go.

Keep in mind, if you receive new Koi from different sources and place them all together, then you have no recourse to go back to that dealer and tell him he sold you an infected koi.  That is why it is important to keep separate Quarantine tanks for each dealer you buy from. Not only tanks; nets, filters anything that comes in contact with the fish or the water.

Sterilization

Ok, now what! .Your koi are all dead You want more koi to replace the ones you lost. Well you can’t place the new koi in the infected tanks... so you have to clean them...

Bleach, Bleach and more Bleach. We filled the 3 tanks downstairs and put in mad amounts of bleach. we ran it through the filters. We then placed all the nets, buckets and anything that had contact in the bleach water. We did this twice and then allowed everything to air dry. We also scrubbed the floors down.

Why so many different Symptoms?

Studies show that secondary infections occur to some koi that have contracted KHV.  I believe this was the case in some or ours. When the symptoms originally occurred we took the Koi to DR. Helen Roberts so she could treat them. She ran the usual protocol... scrape, scope, test water parameters. All came up negative. 3 days later the koi in the import tank started dying off. Mass mortality. The scraping and checking with a microscope is very important as a first step. There are parasites such as costia that will mimic similar symptoms. It is important to check for parasites as a first rule of thumb. If parasites are discovered, treatment needs to be attended to right away.

Quarantine

I can’t stress this enough. When our vet told us she quarantined her koi for a year, I thought she was a loon. Listen to the experts. This virus becomes most active at temperatures around 75 degrees. However 3% of infected koi display symptoms at lower temperatures. We quarantined our new arrivals 75 degrees. Consider this: We received the koi in February. The koi were in chilly water. When we brought the water temps up, the virus reared it’s ugly head. 

This is why mass moralities seem to occur when pond water starts to warm up. When I told the dealer in Tennessee our dilemma, his comment to me was... “Wait till summer comes and the water starts to warm up. your going to see a lot more of this”

The latest thinking to Quarantining your new arrivals is:

1... Place a canary koi with the new koi. If your new koi has KHV, the canary koi will also contract the virus.

Canary’s we’re used in mines. They we’re lowered into the mine and if gasses we’re present the canary would die.

2... Warm the water to 75 degrees for a week and let it drop.

3... Do this repeatedly. The thinking behind this is to stress the koi and weaken his Immune system. Hopefully if the koi is infected the virus may break out.

The hope is if you don’t plan on doing a serology to your koi (which I highly recommend) you are hoping to draw out the virus in the koi in it’s stressed condition.

Finally!

As Lin and I we’re talking we didn’t want to leave you with doom and gloom. We have, since that time added a nice variety to our collection of koi. We also rebuilt our pond with better filtration and design to create a cleaner living environment for our pets. Let’s face it folks. In any hobby there are ups and downs. Every situation brings on new learning experiences from which to grow. Never loose hope. When you have a moment... We made up a site with our pond and a section called our koi.

http://www.NaturesCall.us

Drop us a line and let us know how your using the information.        khvandme@gmail.com

Walt and Lin

Site created 2-22-2007