Successful induction of ovine pulmonary adenocarcinoma in lambs of different ages and detection of viraemia during the preclinical period.
Ovine pulmonary adenocarcinoma (OPA) can be reproduced consistently in neonatal lambs by intratracheal injection of inocula containing jaagsiekte sheep retrovirus (JSRV). In this study, clinical disease, confirmed pathologically as OPA, was induced in a high proportion of lambs that had been inoculated intratracheally with infectious lung fluid at 1, 3 and 6 months of age. The incubation periods, however, were longer in these three age groups than in 1-week-old lambs that were used as controls. Viraemia was detected in all age groups before onset of clinical signs, but occurred later in older animals. These results suggest an age-dependent susceptibility to OPA that could be determined by the availability of JSRV target cells in the ovine lung. The feasibility of inducing OPA in older lambs and detecting JSRV viraemia in preclinical stages enables improved studies on the pathogenesis, assessment of vaccines, diagnosis and control of the disease.
Salvatori
Daniela
D
Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik EH26 0PZ, UK.
González
Lorenzo
L
Veterinary Laboratories Agency (VLA-Lasswade), Pentlands Science Park, Bush Loan, Penicuik EH26 0PZ, UK.
Dewar
Patricia
P
Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik EH26 0PZ, UK.
Cousens
Christina
C
Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik EH26 0PZ, UK.
Heras
Marcelo de Las
ML
Universidad de Zaragoza, Facultad de Veterinaria, 50013 Zaragoza, Spain.
Dalziel
Robert G
RG
University of Edinburgh, Division of Veterinary Biomedical Sciences, Edinburgh EH9 1QH, UK.
Sharp
J Mike
JM
Veterinary Laboratories Agency (VLA-Lasswade), Pentlands Science Park, Bush Loan, Penicuik EH26 0PZ, UK.
D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D004195:Disease Models, Animal; D022141:Jaagsiekte sheep retrovirus / Q000302:isolation & purification; D011648:Pulmonary Adenomatosis, Ovine / Q000473:pathology / Q000821:virology*; D012756:Sheep; D013997:Time Factors; D014766:Viremia / Q000821:virology