Poultry immunosuppressive disease is one of the major diseases that can not be ignored in the poultry industry,its infectious factors cause vaccination failure,secondary infection and mixed infection of pathogens via infestation of poultry immune system,immune organs,immune cells,and bring huge economic losses to the poultry industry.Immunosuppressive diseases hold a huge potential harm because of its subclinical infection and easily misdiagnosed immunosuppression,and bring severe situations and great chall...