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Newcastle disease
Newcastle disease is a highly contagious viral infection affecting chickens, turkeys and other birds. It can cause major losses in Tunisian poultry farms due to its rapid spread. It is closely monitored because some strains can also mildly...
What is it?
Newcastle disease is a highly contagious viral infection affecting chickens, turkeys and other birds. It can cause major losses in Tunisian poultry farms due to its rapid spread. It is closely monitored because some strains can also mildly affect humans.
The disease is caused by a virus of the avian paramyxovirus family, known as Newcastle disease virus. This virus exists in several strains, some more dangerous than others. It multiplies quickly in the respiratory and digestive tracts of infected birds.
Farms with high bird density, poor hygiene or lack of vaccination are more exposed to the disease. Contact with wild birds or newly introduced, unchecked poultry also increases risk. A weakened immune system in young birds also favors infection.
Commonly observed signs
These signs are neither exhaustive nor specific. Only a veterinarian can establish a diagnosis.
Affected birds may show breathing difficulties, drop in egg production, nervous signs such as tremors or twisted neck, and sometimes greenish diarrhea. Mortality can be rapid and high depending on the virus strain. Signs vary according to the bird's age and overall health.
When to consult without delay
This list does not replace veterinary advice. It gathers situations that justify a prompt consultation.
Transmission
The virus spreads mainly through direct contact with infected birds or their respiratory secretions and droppings. It can also spread via contaminated equipment, clothing or water. Transmission to humans is rare and usually limited to mild conjunctivitis in people in close contact with sick poultry.
Diagnosis and care
Diagnosis is the veterinarian's responsibility, based on clinical examination and laboratory tests. Care is decided case by case.
If this disease is suspected, it is essential to isolate the affected birds and quickly contact a veterinarian or official veterinary services. Only a professional can confirm the diagnosis and indicate the appropriate steps to take. Never attempt to treat the animals yourself.
Prevention
Regular vaccination of poultry is the most effective way to prevent this disease. Maintaining good hygiene in farm facilities and limiting contact with outside or wild birds is also recommended. Quarantining new birds before integrating them into the flock is advised as well.
References
WOAH — Organisation mondiale de la santé animale (ex-OIE)
Content reviewed by the TunisieVet editorial team · Updated 08 August 2026
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