Abstract: Two bacteria strains of pathogen were isolated and identified from the pigling sent by the pig farm by autopsy,both of gram-positive bacteria,globular. Further biochemical identifications and hemolysis indicate that the two bacteria strains of pathogen are swine streptococcosis. The two highly sensitive drugs which are screened by the drug sensitive tests have good results in clinical application. Combing with the epidemiological studies,clinical symptoms,pathoanatomical results and the isolation and identification of the pathogen of the sudden death syndrome of the pig from the farm,we draw the conclusion that the main cause of the sudden death syndrome of the sika pig are swine streptococcosis.

Key words: swine streptococcosis; biochemical identify; drug sensitivity test; animal tests