Isolation of adenovirus from lambs with upper respiratory syndrome

Department of Veterinary Science, North Dakota State University, Fargo 58105.

The role of viruses in the etiology of recurrent upper respiratory disease in newly weaned lambs was studied during 1984-1985 at the North Dakota Sheep Experiment Station. Serum samples collected from lambs at weaning, from lambs with signs of respiratory disease, and 3 weeks following the onset of clinical signs were tested for antibodies to ovine adenovirus (OAV), respiratory syncytial virus (RSV), and parainfluenza type-3 virus (PI-3). Virus isolation studies were performed on nasal secretions samples taken at the same time. Parainfluenza type-3 was isolated from 1 of 275 lambs tested, and there was 2.5% overall 4-fold increase in antibody titer to PI-3 during the 2-year study. An adenovirus with a different restriction endonuclease digestion pattern from that previously reported adenovirus strains in the United States was isolated from 13 of 275 nasal secretions collected from lambs at the time of weaning. There was a 17.6% overall 4-fold increase in seroconversion to the adenovirus isolated from the lambs with clinical disease.