Occurrence: Worldwide. Very common. Very virulent NDV is a notifiable disease
Species affected: All. One of the most common respiratory diseases of poultry.
Age affected: All.
Causes: Virus- Newcastle disease virus is a single-stranded, non-segmented enveloped RNA virus belonging to the family Paramyxoviridae. There are three pathotypes: lentogenic (mild disease), mesogenic (moderate disease) and velogenic (severe morbidity and mortality). Spread is airborne by inhalation or by ingestion of the virus.
Effects: Incubation period is 2-15 days. Paralysis, incoordination and central nervous signs following the initial respiratory signs are diagnostic of NDV. Watery eyes and a plug in the eye are seen with lentogenic strains. Coughing, gasping and sane mortality are seen with mesogenic strains. Egg production and quality are affected. It may produce torticollis, paralysis and bloody diarrhoea. High morbidity and mortality occur with velogenic pathotype.

Special note: VVND is a notifiable disease. It is a very common viral disease of poultry worldwide. Most poultry are vaccinated several times against this virus.