Isolation of respiratory bovine coronavirus, other cytocidal viruses, and Pasteurella spp from cattle involved in two natural outbreaks of shipping fever

Objective—To identify cytocidal viruses and Pasteurella spp that could be isolated from cattle involved in 2 natural outbreaks of shipping fever. Design—105 and 120 castrated male 4- to 8-monthold feedlot cattle involved in 1997 and 1998 outbreaks, respectively. Animals—Nasal swab specimens and blood samples were collected, and cattle were vaccinated on arrival at an order-buyer barn from 4 local auction houses. Four days later, they were transported to a feedlot, and additional nasal swab specimens and blood samples were collected. Nasal swab specimens were submitted for virus isolation and bacterial culture; blood samples were submitted for measurement of respiratory bovine coronavirus (RBCV) hemagglutinin inhibition titers. Results—93 of 105 cattle and 106 of 120 cattle developed signs of respiratory tract disease during 1997 and 1998, respectively, and RBCV was isolated from 81 and 89 sick cattle, respectively, while at the orderbuyer's barn or the day after arrival at the feedlot. During the 1997 out...