Interspecies trasmission of equine herpesvirus 1 (EHV-1) from horse to cattle was shown by Crandell et al. (1988). Specific mutations related to the transmission were studied by comparison of five EHV-1 isolates in cattle (BH1247, 3M20-3, G118, G1753, and 9BSV4) using polymerase chain reaction and restriction fragment length polymorphism analysis with added sequencing. G118 and 3M20-3 were the genome type EHV-1 P, while G1753 was the genome type EHV-1 B. BH1247 and 9BSV4 might be other genome types. We could not identify specific mutations related to the interspecies transmission.