2" koi?? LOTS of things can happen to baby koi besides KHV. How long have you had it? Have you added any new fish or plants lately? Have you tested your water? What were the results of the test? How big is the pond? Do you have a filter? We're going to need a lot more information in order to help!

i purchased the fish 8 days ago befoer it died. the pond is about 275-300 gallons. theyre are a few other fish and 2 filtersi havent tested my water but as soon as i can i am going to. what do i use to test the water? i had added one other plant called a sensitive plant from my friends pond.

you may have brought in parasites on the plants or on the new fish. You do need to test your water. Get a water test kit that check pH, kH, ammonia and nitrites. Get the kind that uses test-tubes full of water and you add drops from different regent bottles, not the kind that is just a strip you stick in the water.

250 gallons is VERY small for koi. A koi should have at least 300 gallons each.