VIRAL ETIOLOGY OF ENZOOTIC PNEUMONIA IN DANISH DAIRY HERDS - DIAGNOSTIC-TOOLS AND EPIDEMIOLOGY

Ten outbreaks of calf respiratory disease in Danish dairy herds were i nvestigated by lung lavage, and in eight of the herds paired blood sam ples were tested serologically, In six of the 10 herds bovine respirat ory syncytial virus (BRSV) antigen was detected in the lung ravage flu ids. In only one calf was coronavirus and BRSV detected simultaneously . The paired blood samples confirmed that four of the herds were BRSV- infected, and in one herd the BRSV infection was diagnosed by the pair ed blood samples alone. Significant increases in antibody titres again st coronavirus were observed in two herds, both in combination with ot her virological agents. No adenovirus antigen was detected in any of t he lavage samples, but in two herds a significant increase in antibody titres against adenovirus was observed, Parainfluenza-3 (PI-3) virus was not detected in the lung lavage fluids, and in four of the herds n o antibodies to PI-3 were detected. In three herds no viral involvemen t could be found, The findings suggest that BRSV may be an important c ausative agent in calf respiratory disease in Denmark, even in very yo ung calves.