EXPERIMENTAL BOVINE PNEUMONIC PASTEURELLOSIS .2. GENESIS AND PREVENTION

  • 1 January 1979
    • journal article
    • research article
    • Vol. 43  (3) , 272-279
Abstract
Crossbred Hereford calves (16) were divided into 2 equal groups. The 1st group was vaccinated intranasally with a commercial vaccine against bovid herpesvirus 1 and the 2nd group was unvaccinated. The calves were later exposed to an aerosol of bovid herpesvirus 1 (strain 108) for 5 min. Four calves from each group were subjected to transportation and 4 calves from each group were kept in an environmental chamber for 4 days. Four days after viral aerosol all calves were exposed to an aerosol of Pasteurella haemolytica and the same subgroups were again transported or held in the chamber for 4 days. The calves that did not die from pneumonia were necropsied 10 days after the final day of transport. Pulmonary lesions were present in vaccinated and control animals but were less extensive in the vaccinated calves. Six of 8 vaccinated but none of the 8 control calves survived. Crossbred Hereford calves (8) were divided into 2 equal groups. One group was vaccinated with bovid herpesvirus 1 (strain 108) and the other acted as controls. Four wk later all calves were sequentially exposed to aerosols of bovid herpesvirus 1 (strain 108) and P. haemolytica 4 days apart. Three of the 4 controls but none of the vaccinates died from pneumonia. Every lobe of the lungs in all the controls was affected by pneumonia while no pulmonary lesions were found in the vaccinated calves. The differences in efficacy of the modes of vaccination and the possible role of transport stress are discussed.