Serological Survey to Determine the Occurrence of Blue Tongue Virus,
Bovine Leukemia Virus and Herpesvirus Infections in the Japanese Small
Ruminant Population from Northern Districts

Ovine sera, collected from the northern prefectures of Hokkaido, Aomori and Iwate in Japan, were examined for the presence of antibodies against Blue tongue virus (BTV), bovine leukemia virus (BLV), bovine Herpesvirus type 1, agent of infectious bovine rhinotracheitis (IBR), ovine Herpesvirus type 2 (OvHV-2), agent of sheep-associated malignant catarrhal fever (SA-MCF), and bovine Herpesvirus type 4 (BoHV-4), using agar immune diffusion, serum neutralisation (SN) and enzyme linked immunosorbent assay (ELISA) tests. No animals were positive to IBR, BoHV- 4 or BLV antigens. Antibodies against BTV have been detected in 3 samples (1.11%) in two flocks from Hokkaido. The seroprevalence of OvHV-2 was observed in twelve flocks from the 3 considered prefectures, in 56 sheep and two goats, with 37.66% of samples giving a positive reaction in the serum neutralization test. The infections did not appear to be related to the reduction in sheep productivity. Immune reaction reported in goats could refer to Caprine Herpesvirus-2 (CpHV-2). These results indicate that sheep are reservoirs for OvHV-2 in the field in Japan.