Canine distemper is a worldwide acute and highly contagious viral infectious disease. The natural infection route of CDV is mainly through the upper respiratory tract. After infected with CDV, CDV will attack cells of intestinal epithelial and cardiomyocytes. The main clinical manifestations are gastrointestinal diseases and myocarditis, and most of the puppies are myocarditis. Canine distemper is a kind of infectious disease with high incidence, high mortality and frequent outbreak. Dogs of different ages, sexes and breeds can be infected.