Prevalence of antibodies to seven viruses in a flock of ewes in Minnesota

Blood samples were collected from a flock of healthy ewes at a University of Minnesota research station. Sera from these blood samples were tested for antibodies against 7 viruses, using 3 tests (eg, virus-neutralization test for bovine viral diarrhea virus, infectious bovine rhinotracheitis virus, bovine adenovirus type 3, and bovine respiratory syncytial virus; hemagglutination inhibition test for parainfluenza virus type 3; and agar-gel immunodiffusion test for lentivirus of ovine progressive interstitial pneumonia and bluetongue virus). The number of seropositive ewes for each antibody type were 1 of 377 (0.3%) for bovine viral diarrhea virus, 2 of 377 (0.5%) for infectious bovine rhinotracheitis virus, 29 of 378 (7.6%) for bovine adenovirus type 3, 200 of 378 (52.5%) for bovine respiratory syncytial virus, 273 of 373 (71.7%) for parainfluenza virus type 3, and 210 of 379 (55%) for ovine progressive pneumonia virus. All ewes were seronegative for bluetongue virus antibodies.