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Egg Drop Syndrome Virus

Egg Drop, EDS

Egg drop syndrome virus (EDSV) is disease that affects laying hens, causing them to lay abnormal eggs. EDS is caused by an adenovirus which is prevalent in many wild and domestic ducks and geese. It is believed that the syndrome was first introduced into chickens from contaminated vaccine. Heavier broiler-type breeds and brown egg producing chickens are most severely affected by the disease. Often, the first sign of infection is a change in the color of the egg, quickly followed by production of shell-less and soft-shelled eggs.

Clinical Signs

Change in egg color
Soft-shelled eggs
Shell-less eggs
Decreased egg production
Transient diarrhea


  • Clinical signs
  • Physical exam
  • Laboratory tests


Supportive careIsolate the bird from the flock and place in a safe, comfortable, warm location (your own chicken "intensive care unit") with easy access to water and food. Limit stress. Call your veterinarian.
VaccineInactivated vaccines with oil adjuvant are available and, if properly made, control the disease. They reduce but do not prevent virus shedding.




Scientific References