Occurrence: Worldwide, though not reported in chicks in US. The virus has been isolated from non-symptomatic migratory ducks in the US.
Species affected: Laying chickens, ducks, guinea fowl.
Age affected: Adult.
Causes: Avian adenovirus.
Effects: Incubation period is 7-9 days. Loss of colour in pigmented eggs, thin-shelled, soft- shelled or shell-less eggs and a reduction in production up to 40%. Watery albumin and reduction in egg size. Inappetance, dullness and diarrhoea may occur.
Egg drop syndrome (EDS 76)
Egg drop syndrome is an acute to chronic disease affecting laying birds, ie. laying chickens, ducks and guinea fowl. It is caused by the avian adenovirus, which is 70-75nm in length. All chickens are susceptible, but brown layers are most susceptible.
It can spread vertically through the embryonated egg, by faecal-oral routes, and by contaminated water. Wild ducks, geese, gulls, owls, storks, swans and egrets can transmit the virus mechanically.