EDS is a disease that can cause a sudden decline of egg production in chicken, except the production decline there are some more symptoms. such as discoloration of the shell, its become״waiter" the shell become thiner, and evan no shell eggs. The pathogen that cause EDS is a virus called Adenovirus. The natural pool of this virus is in water fowl like Ducks, Gees etc. the virus causes no harm to the water fowls but when it comes in contact whit chickens it causes EDS. The Adenovirus entered to chickens also throw the Marek׳s disease vaccine because the virus that was used to make the vaccine was grown on cells from duck embryos which was infected whit the Adenovirus. The conclusion from this is to separate chickens from ducks and gees,and to keep maximum bio security in your flock.