Ictalurid herpesvirus 1 (IcHV1), commonly known as channel catsh virus, is the rst identied and characterized herpesvirus of sh . This virus causes channel catsh virus disease (CCVD), a severe hemorrhagic viremia in young channel catsh (Ictalurus punctatus). Given that losses to CCVD can exceed 90% of the affected population within a 2-week period, this disease is of concern to aquaculturists that produce channel catsh. This virus is easily identied in acutely infected individuals, but latent IcHV1 infections can be difcult to detect. A related alloherpesvirus designated Ictalurid herpesvirus 2 (IcHV2) has been detected in Italy from another North American freshwater catsh, the black bullhead (Ameiurus melas) experiencing hemorrhagic viremia similar to CCVD . The distinction between the two virus species is important in diagnostic evaluation because the channel catsh may be extremely sensitive to IcHV2  and it is not known to occur in North America where the largest stocks of wild and aquacultured channel catsh occur.