Newcastle Disease in Poultry

Newcastle Disease remains a serious threat to poultry worldwide, especially in regions with limited veterinary infrastructure. However, with proper vaccination, strict biosecurity, and early detection, outbreaks can be minimized and controlled.
 

What is Newcastle Disease?

Newcastle Disease (ND) is one of the most dangerous and rapidly spreading viral infections in poultry, caused by the Paramyxovirus group. It affects birds of all ages and can devastate commercial flocks with high mortality rates. The disease is marked by hemorrhages and ulceration in the digestive tract, severe respiratory distress, and neurological disorders.  
Newcastle Disease Virus (NDV) has multiple evolving strains, making control and prevention a global challenge. Although the virus is easily destroyed by common disinfectants, it can survive for years in cool environments, contributing to its persistence and global spread. 
 

How is Newcastle Disease Transmitted?

Newcastle Disease spreads quickly via: 

• Inhalation of contaminated air droplets  
• Ingestion of contaminated feed or water  
• Contact with infected birds, equipment, or caretakers  
• Contamination from wild birds, rodents, and insects 

The virus is shed in respiratory secretions, droppings, and eggs, and can infect poultry across wide regions within days.
 

Incubation and Symptoms 

The incubation period is typically around 5 days, but it may vary from 5–12 days depending on strain and host factors.

Acute Form

• Sudden loss of appetite
• Lethargy, drowsiness
• High fever (up to 42–43°C)
• Nasal discharge, sneezing, and wheezing
• Severe diarrhea; classic white, chalky feces
• Cyanosis of comb and wattles
• Rapid drop in egg production; malformed, soft-shelled, or undersized eggs
• Inflamed cloaca

Chronic Form

• Nervous signs: twisted neck, tremors
• Abnormal movement: walking in circles or backward
• Seizures triggered by stimuli

Prevention and Treatment

There is no specific antiviral treatment for NDV. However, supportive care and immunotherapy can improve recovery rates.
Effective prevention requires a combined approach:

Vaccination

• Lasota Vaccine: for birds under 2 months old
• Newcastle I (System I) Vaccine: for birds over 2 months old

Both vaccines are suitable for quails, ducks, pigeons, geese, and muscovy ducks
 

Biosecurity Measures

• Regular disinfection of housing and tools
• Isolate new or sick birds
• Restrict visitor access
• Protect flocks from wild birds and rodents

Newcastle Disease vs. Other Poultry Diseases

ND can be mistaken for avian influenza, infectious bronchitis, or Marek’s disease. Always consult a veterinarian for proper diagnosis and disease management.

FAQs

Q1: Can Newcastle Disease affect humans?
A1: In rare cases, it causes mild conjunctivitis in humans handling infected birds. It’s not a major public health risk.

Q2: Can Newcastle Disease be cured?
A2: There is no specific treatment. Supportive care and vaccination are the main control methods.

Q3: How often should poultry be vaccinated against ND?
A3: Chicks are usually vaccinated at day-old and again at intervals depending on local risk and vaccine type.