Quarantine and KHV

Quarantine and KHV

By Karl Schoeler

Quarantine your Koi!!!

The next time you acquire a new fish it should be quarantined for at least six to eight weeks in water from your pond or from your mains supply. In addition it is always good to place one of your present collection with the newcomer. A buddy is always good, and it insures that the existing population will not be adversly affected by the newcomer's bugs. I assure you, they will have bugs.
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\r\nQuarantine tanks are a necessity. Many people sadly relate their experiences putting a new fish in with the existing population and watching as they all begin to behave in unusual ways and one by one begin to die.
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\r\nHere's a setup which can go in the garage, or the basement. Pearls of Paradise has two sizes of collapsible show tanks. Setting up one of these takes just a few minutes, and it can be left up until the new fish(and a buddy from the existing population)are introduced back into the main herd. It needs to have a filtration system, and I've had very good luck simply using a 55gallon drum as a trickle filter filled with floor stripping pads or spiral cut pvc.(EasyClean). Bulkhead assemblies, valves and pvc pipe for piping through the drum as well as fernco adapters(rubber clamp devices) are available at any farm store and most of the big box hardware stores and Aquatic Eco Systems(Florida). A 500 to 1000gpm submersible pump will handle that size filter very well, turning over the system frequently.
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\r\nIf you'd like something a bit more permanent as well as very strong, the bulk water tanks at the farm stores work very well also. In either case make sure you cover them securely with netting or plastic. Fish in unfamiliar territory and water will jump!
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\r\nThe temperature in this tank needs to be in the mid-seventies and remain that way throughout the oftlinequarantine time. This temperature will give medications the best chance to do their job. It also may "prove" whether the new fish have KHV. Koi Herpes Virus. KHV can sometimes "break" at this temperature and the affected fish will die quickly. There is no known cure. So if you decide not to quarantine you could be setting up your existing population for a horrible death. Quarantining is much much more than important. It is the most important thing you can do to prevent losses and heartbreak for you and your family.
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\r\nTo be a bit more specific about KHV:
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\r\nKHV has been found in nearly every country in the world. It affects ornamental as well as riverine carp. There are several groups working on it, but so far about the only thing we as hobbiests can do it quarantine and take a blood sample from the fish for Virus Neutralization testing at the University of Georgia Infectious Disease Laboratory.(Serology)
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\r\nRegarding KHV:
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\r\nThe "intelligence" which is being spread around the hobby says that koi must be brought up to about 75*F and held there. It is said that the virus will "break" at this temperature and that it takes 14 to 21 days for it to happen.
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\r\nIt is said that "cycling" the temperature to lower temperatures and back up again will provide evidence that the fish are either free of KHV or that they will shows symptoms and die shortly therafter.
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\r\nThat point should be tempered with:
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\r\nThe virus does NOT NECESSARILY BREAK if the temperatures are at the "trip point". It needs another factor. Stress. If the carrier is producing antibodies the virus will remain hidden until such time as the fish has been stressed and becomes vulnerable to an outbreak by the virus. So it is extremely important to learn what it takes to draw a blood sample yourself and submit it properly to the University of Georgia for testing.
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\r\nIt is still important to hold the temperature of waters housing new arrivals around 75*F for two to three weeks before testing. Koi which are producing antibodies will test positive when samples are drawn and tested. These positive results are indicative of a previous exposure "waiting for the right moment" to break. In my opinion those which test positive must be euthanized immediately. I have done so myself on three new imports. Not a pleasant task but one which I chose as an alternative to potential infection of a large group. 97 koi to be exact.
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\r\nAlthough it is certainly an argumentative point it is also said that even though you may have discovered a carrier within a group it is highly unlikely that the remaining members have been exposed as the carrier/s are not shedding the virus. That probably can be proved by an additional test several weeks down the road.
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\r\nWhere does this leave the hobbiest? Unsure to say the least. So we must continue to demand testing and isolation for our new koi. Fortunately there are importers willing to help in this regard and we must buy from a reputable one who not only offers this but is willing to hold the tested fish in quarters which are separate from all others.
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\r\nSome dealers are going the extra mile, and some are sticking their heads in the sand. If you're planning on buying quality koi, I'd urge you to demand that your fish be tested with serology. It's not 100% but it is ithe best we have at the moment. Just because koi have been "quarantined" does not mean the fish you receive will not infect and kill every one you own. You are the last defense in protecting your collection. Quarantine with pristine, well filtered water. Test your water parameters frequently. Have your fish tested or learn how to do it yourself. It is really not that difficult.