Further evidence for a retrovirus as the aetiological agent of sheep pulmonary adenomatosis (jaagsiekte).

The infective agent of jaagsiekte was shown to be present in the fluid which accumulates in the respiratory tract of sheep during the terminal stages of the disease. The fluid also contained reverse transcriptase (RT) activity which showed a clear preference for a ribonucleic acid synthetic template over the corresponding deoxyribonucleic acid template and which utilised the RT specific template/primer poly (2'-0-methylcytidylate) oligodeoxyguanylate. This enzyme activity was associated with a particle which had typical retroviral buoyant densities in a range of gradient media.