Newcastle disease (also called Avian Distemper, Paramyxovirus or Fowl Pest) is common worldwide, but currently outbreaks in the UK and the USA are relatively rare.
Newcastle disease is a respiratory disease caused by a virus and was first discovered in Newcastle upon Tyne, England in 1926, with other strains being simultaneously discovered in other parts of the world. Generally the strain of the Newcastle virus found in the USA and the UK is relatively mild, but continual vigilance is exercised, especially over the import of exotic birds, who may carry more virulent strains.
Symptoms include coughing, sneezing, gurgling and holding the beak wide open in an attempt to breathe more freely. Chickens may also get diarrhoea and stop laying eggs, or lay eggs with soft shells. After a few weeks, sometimes nervous system problems can occur, with the birds developing twisted necks, droopy wings and dragging legs.
Transmission occurs through inhalation of the virus via the respiratory discharges from carriers or ingesting it via other excretions, e.g contaminated feed.
Commercial chicken flocks are vaccinated against the disease and if there is an outbreak nearby you will probably by law have to vaccinate your flock too.
Newcastle disease is a notifiable disease in the UK and most developed countries and if you suspect that your birds have Newcastle disease, you should report it immediately to your local Animal Health Office.