To examine protection against a virulent strain of CSFV at
21 days after i.m. injection of the CSF vaccine, four vaccinated pigs
and two control pigs were challenged with CSFV and monitored for
20 days. The vaccinated pigs showed no evidence of leukopenia
and maintained a normal body temperature throughout the
observation period; however, the two control pigs died at 16
and 18 days after CSFV challenge after showing clinical symptoms
specific for CSF. Necropsy was performed on the four surviving
pigs. Gross findings revealed no lung collapse. The lungs appeared
reddish, with purple lobar or lobular consolidations in both
cranioventral lobes. Dark red or reddish purple lobar or lobular
consolidations were localized to several lobes. The pigs also had
swollen lymph nodes, reddish petechia in the kidneys, and reddish
petechia in the urinary bladder. Histological analysis revealed non-
suppurative meningitis, non-suppurative encephalitis,