Symptoms of Newcastle Disease

The symptoms vary a lot depending on the virus strain causing the disease. One or more of the following body systems are attacked:

• the nervous system
• the respiratory system
• the digestive system
• Most infected chickens will show respiratory problems such as:
  • gasping
  • coughing
  • sneezing

  Newcastle disease is well-known for the effects it has when it attacks the nerves in the chicken’s body:

  • tremor, spasms, and shaking movements in one or more parts of the chicken’s body
  • difficulty walking, stumbling, and falling on the ground
  • paralysis of wings and legs or complete paralysis
  • twisted neck and strange head positions

  Since the digestive system is put under pressure, you can also notice:

  • green, watery diarrhea
  • blood in the diarrhea

  Many chickens will only show mild signs of general illness and exhaustion, especially for mild virus strains or when the birds are vaccinated.

  In laying hens, there is a sudden egg drop, and it’s possible to see shell-less eggs.

  Generally, it takes about 6 days to see some signs of infection, but it can take up to two or three weeks in some cases. In severe cases, the virus may result in sudden death without the sign of any clinical symptoms. Vaccinated birds can be asymptomatic but can still pass on the virus to other chickens.