What is Newcastle Disease (ND)?

July 20, 2024

Brazil's agriculture ministry recently declared an animal health emergency in the country's southernmost state of Rio Grande do Sul after a case of Newcastle disease was detected on a poultry farm.

About Newcastle Disease (ND):

  • It is a highly contagious and often severe disease found worldwide that affects birds, including domestic poultry.
  • It is caused by a virus in the family of paramyxoviruses.
  • It attacks their respiratory, nervous, and digestive systems.
  • ND only affects birds, particularly poultry, such as chickens.
  • It can cause illness and death in large numbers of birds quickly.
  • Transmission:
    • ND is transmitted most often by direct contact with diseased or carrier birds.
    • Infected birds may shed the virus in their feces, contaminating the environment.
    • Transmission can then occur by direct contact with feces and respiratory discharges or by contaminated food, water, equipment, and human clothing.
    • ND viruses can survive for several weeks in the environment, especially in cool weather.
  • The disease is very contagious. When the virus is introduced into a susceptible flock, virtually all the birds will be infected within two to six days.
  • Symptoms: Infected birds may show signs of:
    • loss of appetite, coughing, gasping, nasal discharge, watery eyes, bright green diarrhoea, and nervous signs such as paralysis and convulsions
    • combs and wattles may look swollen, enlarged, and discoloured (purple or blue)
    • reduced egg production, and the few eggs that are produced may be soft shelled and malformed.
  • Treatment:
    • There is no treatment for ND, and, in many countries, infected and susceptible birds in the vicinity of an outbreak are culled to contain transmission of the disease.
    • Prevention is accomplished through vaccination and strict biosecurity