Bronchiolo-alveolar carcinoma has been described in man and in several animal 
species, including cattle, dogs, opossums, goats and sheep. In sheep, a 
bronchiolo-alveolar carcinoma, known as ovine pulmonary carcinoma (OPC), is 
caused by jaagsiekte sheep retrovirus (JSRV), an exogenous type D retrovirus. In 
the mid-1980s, a severe outbreak of a disease resembling OPC was described in 
captive Sardinian moufflon (Ovis musimon). In the present study, the use of 
polymerase chain reaction (PCR) amplification of nucleic acids extracted from 
archival material established that JSRV was associated with OPC in affected 
moufflon. JSRV was detected in the lungs and mediastinal lymph nodes. 
Immunohistochemical and in-situ PCR demonstrated that in the lungs, JSRV 
proviral DNA was localized in transformed and untransformed type II pneumocytes 
and in the alveolar macrophages. In the mediastinal lymph nodes, JSRV DNA was 
mainly located in the cortical follicles and paracortex. These data suggest that 
JSRV is the cause of OPC in Sardinian moufflon, as it is in Sardinian sheep.