How to prevent and treat duck hepatitis? Introduction to practical prevention and treatment methods

For the prevention and control of this disease, according to the characteristics of the disease, the focus should be placed on environmental sanitation control and immunization of breeder ducks, among other aspects.

(1) Environmental sanitation control: This disease can be prevented by strict isolation measures. Ducklings under 4 weeks of age are susceptible to DHV, so raising ducklings within 4 weeks of age in isolation to prevent DHV infection can effectively control the occurrence of DHV. Implementing strict disinfection is an important measure to prevent this disease. Before each batch of ducklings enters the duck house, the duck house should be sprayed and disinfected with a 5% sodium hydroxide aqueous solution, etc., and personnel entering and leaving should take disinfection measures. Once this disease breaks out, isolation should be carried out immediately and the duck house should be thoroughly disinfected.

(2) Vaccine immunization

1. Attenuated vaccines: At present, several attenuated vaccine strains such as QL79, E52, CE81 and Fc are widely used in production. The use of attenuated vaccines for immunization includes two situations: (1) Breeder duck immunization: 2 to 4 weeks before collecting hatching eggs, two immunization injections are carried out at 1-week intervals. DHV antibodies are transmitted to ducklings through the eggs, and ducklings can obtain maternal antibody protection after 2 weeks. The general immunization period is 6 months, and a second immunization should be considered after 5 to 6 months; (2) Duckling immunization: Immunizing 1-day-old ducklings with attenuated vaccine can produce immunity in 3 d to 7 d, but maternal antibodies can affect the immune effect, and in production practice it often happens that ducklings develop the disease before immunity is produced, making the immune effect unreliable, so it is not widely used in production.

2. Inactivated vaccines: If basic immunization with attenuated vaccine has been carried out, oil-adjuvant inactivated vaccine can induce the duck body to produce high-titer antibodies; otherwise, the antibody level is very low. In some areas and duck farms where the disease is severely prevalent, 1 month before the breeder ducks begin laying, attenuated vaccine is first used for immunization, and one week later oil-adjuvant inactivated vaccine is used for booster immunization, which can enable the next generation of ducklings to obtain higher-titer maternal antibodies.

At present, in production practice, attenuated vaccines are generally widely used, while inactivated vaccines are rarely used because of their high price and long time required to produce immunity.

(3) Use of specific antibodies.

1. For ducklings without maternal antibody protection, each duck can be injected subcutaneously with 0.5 ml to 1 ml of hyperimmune serum or hyperimmune yolk fluid at 1 to 2 days of age, which can effectively prevent the occurrence of DVH.

2. In the early stage of a DVH outbreak, each duck can be injected subcutaneously with 1.5 ml to 3 ml of hyperimmune serum or hyperimmune yolk fluid, which can effectively control the spread of DVH. If there is secondary or mixed bacterial infection, adding sensitive antibiotics gives an even better effect.