Sabrina L. Swenson, DVM, PhD; Jeff J. Zimmerman, DVM, PhD; John G. Landgraf; Merwin L. Frey, DVM, PhD; Andy Brevik, MS; Howard T. Hill, DVM, PhD; Michael J. McGinley, PhD
Weaned pigs free of porcine reproductive and respiratory syndrome virus (PRRSV) antibodies were challenged intranasally with PRRSV.
After challenge, blood and nasal swabs were collected until the pigs reached market weight.
Samples were evaluated for the presence of PRRSV and PRRSV antibodies. Once the pigs reached market weight (110 days postchallenge), they were injected daily for 5 days with dexamethasone. After challenge, virus was isolated from nasal swabs and plasma and pigs developed PRRSV antibodies.
Virus was not isolated from nasal swabs or plasmas after dexamethasone administration and serum antibodies did not increase