[Role of the virus of Aujeszky's disease in respiratory diseases of swine].

Studies carried out on pig-breeding farms have established the presence of Aujeszky's disease virus in cases of bronchopneumonia in pigs. On seven out of eight farms with bronchopneumonia the virus wad demonstrated both virologically and serologically, and nearly 50 per cent of the examined diseased pigs on these and other farms had antibodies. The individual serologic studies of pigs having antibodies revealed that the antibodies appeared in the second month of the animals' fattening. This corresponded to the manifestation of the initial symptoms of bronchopneumonia in the respective group.