The SPF pigs of 4 weeks old were inoculated with NY,-BVD, prepared from infected bovine spleen, and 16 pig-passaged BVD virus respectively. After inoculation, no clinical signs was observed. This test was emphasized on clinical observation, pathological lesions and virus distribution. The inoculated pigs were killed on 3, 6, 9, 12 and 15 days postinoculation.
On pigs vaccinated with NY,-BVD prepard from bovine spleen, the virus could not be detected on the 3rd day postinoculation The virus was initially isolated from mesenteric, subiliac lymph nodes and spleen. on 6th. days postinoculation. On the 9th day, the virus was isolated from each organ.
On the 15th day, BVD virus was isolated noly from rnesenteric lymph node and spleen or kidney.
When 16 pig-passaged BVD virus was given to the pigs, it could be isolated from mandibular, mesenteric, sternal lymph nodes and spleen on the 3rd day postinoculation. On the 6th day, the virus was recovered from each organ. On the 15th day, some lymph nodes only revealed the viral existance. It indicated only lymphatic infection.