END is a contagious and fatal viral disease affecting all species of birds. END is one of the most infectious diseases of poultry in the world and is so deadly that many birds die without showing any signs of disease. A death rate of almost 100 percent can occur in unvaccinated poultry flocks. It can infect and cause death even in vaccinated birds.
What Are the Signs?
END affects the respiratory, nervous, and digestive systems. The incubation period for the disease ranges from 2 to 15 days. An infected bird may show the following signs: Sneezing, gasping for air, nasal discharge, coughing; Greenish, watery diarrhea; Depression, muscular tremors, drooping wings, twisting of head and neck, circling, complete paralysis; Partial to complete drop in egg production; Production of thin-shelled eggs; Swelling of the tissues around the eyes and in the neck; Sudden death; and Increased deaths in a flock.
How Does END Spread? END is spread mainly through direct contact between healthy birds and the bodily discharges of infected birds. The disease is transmitted through infected birds' droppings and secretions from the nose, mouth, and eyes. END spreads rapidly among birds kept in confinement, such as commercially raised chickens.
Virus-bearing material can be picked up on shoes and clothing and carried from an infected flock to a healthy one. The disease is often spread by vaccination and debeaking crews, manure haulers, rendering truck drivers, feed delivery personnel, poultry buyers, egg service people, and poultry farm owners and employees.
The END virus can survive for several weeks in a warm and humid environment on birds' feathers, manure, and other materials. It can survive indefinitely in frozen material. However, the virus is destroyed rapidly by dehydration and by the ultraviolet rays in sunlight.