Abstract
Summary The isolation of swinepox virus in primary pig kidney cell cultures is reported. The differentiation from vaccinia virus was possible with challenge infections of convalescent pigs and the use of the agar gel diffusion precipitation (AGDP) test and immuno-electroosmophoresis (IEOP). Using both immune precipitation tests reactions of identity were obtained between the heterologous antigens of swinepox and vaccinia viruses. A total of 829 pig sera from the field were tested for precipitating antibodies with the IEOP. Antibodies were detected in 65 (=7.8 per cent) of these serum samples.