26 March 2026
Newcastle Disease (NCD) is a Category A, notifiable disease. NCD is a highly contagious virus, often fatal, which affects domestic poultry and wild birds. Rebecca Tierney, Poultry Adviser, tells us more
The disease has a rapid onset of symptoms, it is very contagious with up to 100% mortality if a susceptible flock becomes infected.
The symptoms of NCD include:
Lethargy
Reduced appetite
Respiratory distress
Clear mucus discharge from the mouth
Drop in egg production
Mortality (up to 100% in severe cases)
There have been numerous cases of NCD in Europe in recent months. One of the most recent cases being confirmed in Spain on March 9th in a laying flock. This is the sixth case in Spain during this season. Spanish authorities have implemented strict control measures as per Commission Delegated Regulation (EU) 2020/687.
A key concern with this outbreak, is that the flock had been correctly vaccinated against the disease. This did not prevent the introduction of the disease to this flock. Further cases have been reported across Europe; Poland, Lithuania and Germany.
As clinical symptoms of NCD are similar to that of Avian Influenza, it is crucial for laboratory testing to be carried out to get accurate diagnosis. The disease can be transmitted by direct contact with infected birds, or through environmental contamination from faeces or respiratory droplets. Contaminated equipment, clothing and vehicles can also be a route of transmission.
Therefore, biosecurity measures are very important in a bid to prevent the spread of the disease. These measures will be the same as though to protect flocks against AI (bird flu).
While Ireland has not had a case of Newcastle Disease in almost three decades, the last case was in 1997, the risk has now increased due to the virus circulating in Europe. The need to maintain biosecurity measures is even more important now with the risk of Avian Influenza and Newcastle Disease circulating.
Note: While vaccination is an excellent biosecurity tool, it is not guaranteed to be 100% effective. it is very important to maintain all biosecurity measures.