The difference between the two virus is done by really specialist. When you compere the ADN and ARN of different virus affecting a specific animal, you'll always find a little sequence on ADN or ARN wich is specific for that animal. Tha's why specialist can determinate wich animal the virus could affect.
If you want to see virus on microscope, you need an electronic one and you might have to sell your house to have enough money to buy an occasion one.
And finaly, there is no risk for human to handle Koļ infected by KHV, eccept for the monney you'll lose.
Marco