Duck viral hepatitis Duck viral hepatitis is an acute infectious disease caused by duck viral hepatitis virus, which is characterized by hemorrhagic inflammation of duck liver. The disease is characterized by rapid onset, rapid spread and high mortality. The pathological changes of infected ducks are hepatitis and bleeding. The disease often causes serious economic losses to duck farms. There are three serotypes of the virus, namely type I, type II and type III.

Duck hepatitis virus, HBV) is a prevalent serotype I virus in China, which is characterized by hepatomegaly, hemorrhage and neurological symptoms of infected ducks. In newly infected areas, the mortality rate of the disease is as high as over 90%. The disease mainly affects ducks, mainly through contact, and respiratory tract can also be infected. The mortality rate of ducks can reach 95% within 1 week, and adult ducks do not get sick.

This disease has been prevalent in China since the early 1980s, and it can be immune controlled by attenuated duck virus hepatitis I vaccine. Since 1997, this disease has been seriously prevalent in some areas. The standard attenuated vaccine of duck viral hepatitis I can not completely control the epidemic situation, and it is suspected that there are duck viral hepatitis I virus variants. Duck hepatitis can cause serious death of ducklings, and the mortality rate of sick ducklings is high.

The ducklings are characterized by confusion, frequent convulsions, spotty liver bleeding, gallbladder enlargement and pale bile. Vaccination is an effective preventive measure, but in some epidemic areas with poor sanitary conditions and frequent hepatitis, 10 ~ 14-day-old ducklings still need active immunization.

At the age of 1 day, subcutaneous or intramuscular injection of 0.5 ~ 1.0 ml attenuated live vaccine can protect the offspring of non-immunized ducklings. Duck plague canine distemper is an acute infectious disease of ducks, geese and swans. It is characterized by blood vessel destruction, tissue bleeding, digestive tract mucosal ulcer, lymphatic organ injury and parenchymal organ degeneration. The disease spreads rapidly, with high morbidity and mortality, which seriously threatens the development of duck industry. Duck plague virus belongs to herpesviridae, classified as α-herpesviridae.

This virus does not agglutinate red blood cells of poultry and mammals. Ducks of different ages and breeds can be infected, the morbidity and mortality of adult ducks are more serious, and the morbidity of ducks under 1 month is lower. The main route of transmission is digestive tract, but also through conjunctiva and respiratory tract infection, and blood-sucking insects may also become the carrier of this disease.