Abstract
Meningo-encephalitis in feedlot cattle sporadically occurred in the Tokachi area in northern Japan. The calves had been vaccinated intranasally with a mixed live-vaccine (infectious bovine rhinotracheitis virus, bovine viral diarrhea-mucosal disease virus, and parainfluenza 3 virus) for which intramuscular inoculation was indicated. Two additional live vaccines, bovine adenovirus type 7 and bovine respiratory syncytical vilus, had been inoculated simultaneously. Eleven isolates of bovine herpesvirus type 1 were plaque-purified from two brains with fatal encephalitis; their viral DNAs were examined by restriction endonuclease analysis (REA) using PstI and HindIII. The REA patterns of the virus clones were almost identical to those of the vaccine strain 758-43, suggesting that the isolates from this outbreak of fatal encephalitis originated in the abnormally administrated vaccine.
