synonym “duck plague” DVE
A herpes virus.
Occurrence and Economic Significance
Duck viral entertitis occurs in all areas where ducks and geese are raised. The infection is responsible for severe losses in susceptible flocks.
Duck viral enteritis is transmitted directly by contact of susceptible birds with infected viremic ducks or recovered carriers. Concentration of ducks in intensive production areas and common use of ponds by commercial flocks and migratory and free-living resident waterfowl predisposes to infection.
Morbidity varies according to the strain of virus and the susceptibility of the flock and may range from 10% to 100% with a corresponding mortality rate.
Ducks are usually infected from three weeks onwards with an incubation period of 5 to 7 days.
Mature breeding flocks show a precipitous decline in egg production immediately preceding a significant rise in mortality.
Affected ducks demonstrate extreme depression, ruffled plumage, diarrhea and photophobia.
Clinical signs in mature ducks composed paresis, flaccidity of the neck and terminally, tremors of the head and limbs. These signs should be differentiated from botulism. Highly pathogenic strains of the virus may cause hemorrhages from the nares and cloaca.
Characteristic lesions of duck viral enteritis include:
Characteristic lesions are highly suggestive of the diagnosis. Histological examination discloses the presence of intranuclear inclusion bodies in hepatocytes.
The viral agent can be isolated in 10-day old embryonated duck eggs inoculated by the chorioallantoic route. Retrospective diagnosis is based on demonstrating a marked increase in neutralization titers comparing sera from acute, newly infected and recovered ducks. It is important to differentiate duck viral enteritis from highly pathogenic avian influenza, botulism, pasteurellosis and duck viral hepatitis.
A live attenuated chicken-embryo derived vaccine has been used in Europe to prevent outbreaks. Where possible, commercial ducks should be isolated from free-living waterfowl which are reservoirs of infection.
Fowl cholera is a contagious, bacterial disease that affects domestic and wild birds worldwide. It usually occurs as a septicemia of sudden onset with high morbidity and mortality, but chronic and asymptomatic infections also occur.
Newcastle disease is an infection of domestic poultry and other bird species with virulent Newcastle disease virus (NDV). It is a worldwide problem that presents primarily as an acute respiratory disease, but depression, nervous manifestations, or diarrhea may be the predominant clinical form. Severity depends on the virulence of the infecting virus and host susceptibility. Occurrence of the disease is reportable and may result in trade restrictions.
Fowl cholera is the reason for great economic loss of poultry in bangladessh