Bovine Viral Diarrhea Infection in Pigs

Abstract

SUMMARY Sixty-six pigs were exposed experimentally to bovine viral diarrhea ( bvd ) virus. Several strains of the virus and routes of administration were utilized. The immunologic, pathologic, serologic, and virologic responses of pigs in selected groups were determined. In a group of pigs exposed twice to a field strain of virus, the serologic responses consisted of moderate to high bvd antibody titers and low cross-neutralizing titers against hog cholera ( hc ) virus. When given virulent hc virus, severe clinical reactions occurred in the BVD-exposed pigs, but 8 of 9 pigs survived. Further evidence of a viremia was established by the isolation of bvd virus from 7 pigs. Isolates were cultured from the lungs of 1 pig and the blood of 5 pigs exposed intranasally ( i.n. ) In 2 pigs, the blood isolates were detected 14 days postexposure ( dpe ). Isolates were recovered from the ileum, mesenteric lymph nodes, and spleen of 1 pig exposed intramuscularly ( i.m. ). In 2 swine herds investigated for hc , serologic tests for bvd were done after low to moderate hc antibody titers were detected. In each case, higher bvd antibody titers were detected, suggesting that the former were crossneutralization titers resulting from bvd infection. One herd had been in contact with BVD-vaccinated cattle and the other herd had been fed bovine offal.