Studies on the pathogenicity of bovine herpesvirus type 5 in sheep

Four Merino lambs were intranasally inoculated with bovine herpesvirus type 5 (BHV-5) reference strain N569, Two lambs were mock-inoculated as negativ e controls. The virus-inoculated animals developed apathy, inappetence, rhi nitis, nasal, ocular and genital discharge, slight diarrhea and neurologica l disorders, like tremor and salivation. BHV-5 was isolated from the nasal discharge in two of the animals, while the polymerase chain reaction (PCR) detected the virus in all the infected lambs. Two lambs died on post infect ion day (PID) 13, while the other two infected animals were euthanized on P ID 15 and 30, Gross pathological changes were not observed, however, histop athological examinations revealed diffuse nonsuppurative meningo-encephalit is in all infected animals. Viral antigen was detected by immunohistochemis try and viral nucleic acid was revealed by in situ hybridization in the bra in of the two lambs, which died on PID 13, The virus was demonstrated by vi rus isolation and by PCR from different organs of all the infected animals. Slight rise of antibodies was observed in the infected animals from PID 15 , The results show that BHV-5 is able to cross the species barrier and may establish infection in sheep. (C) 1999 Elsevier Science Ltd. All rights res erved.