Detection of equine herpesvirus 1 DNA in a single embryo and in horse semen by polymerase chain reaction

The genome of one equine embryo and three equine semen specimens collected from a Brazilian farm were tested by polymerase chain reaction (PCR) for the presence of EHV-1 and EHV-4-specific timidine kinase (TK) sequences. The PCR detected specific EHV-1 TK gene sequences in all samples tested. The peripheral blood leukocytes (PBL) of the embryo donor mare also was amplified by EHV-1 TK primers. Infectious virus was not recovered from any specimens. The animals did not show any clinical signal of EHV-1 or EHV-4 infections. EHV-4 was not detected in the studied specimens. The results indicate that PCR was more sensitive than virus isolation in cell culture for detecting EHV-1 in semen of carrier horses