Newcastle disease is a widly contagious disease in poultry and other wild birds including Turkey, geese, ducks, guinea fowl, quails, pigeons, ratites e.g Ostriches.
In poultry, the disease is more common in hens and they can be affected at any age. ND are caused by Paraxymoviruses (Paramyoxiviridae family) and depending on their host, vaccines can give a short to long term immunity depending on prior vaccinations.
Signs & Symptoms
Newcastle Disease is characterised by marked variations in morbidity and high death rate amongst the flock. Highly virulent strains lead to death of infected bird 90% of the time.
Physical symptoms include
- Greenish watery Diarrhea
- Gasping for breadth like one suffering from an asthma attack.
- Intermediate virulent strains produce severe nervous and respiratory signs such as Depression, twisting of head and neck, circling, paralysis, swelling of tissue around the neck. Some birds will spin around in gyratory movements, jump off the ground to heights of six to ten feet before crashing to the ground.
- Rough or thin shelled eggs or significant drop in egg production
- When disected, there are harmorhagic lesions on the alimentary canal from the beak leading to the vent, Haemorhages gathered between the gizzard and oesophagus.
- Oedematous Mucus coat
Any potentially infected bird showing symptoms must be isolated immediately and should be confirmed in a laboratory before administering drugs.
Causes of Newcastle Disease
Once a bird has been infected, the virus can spread rapidly. It has been known to kill a whole flock in thousands due to exposure to infected birds. This is common in commercial laying birds kept in cages hence containment should be priority.
The most common route of transmission is orally via excreta which contaminate the feeding area, water, equipment and clothing. The virus can survive in warm & humid regions exceptionally well, feeding on bird feathers and manure heaps around the enviroment.
Some birds have demostrated shedding the virus in their body for over 1 year such as Commorants and birds of the Psittacidae (parrot) family.
Airborne or contact transmission are much less common, therefore a well sanitized enviroment for your poultry is a good deterrent for wide range of transmittable diseases.
Treatment of Newcastle Disease
There are currently no known treatment for NDV. However use of vaccines & sanitary measures reduce it’s likelihood
Use of inactivated viral vaccine or Thermotolerant vaccines help to prevent Incidence of Necastle Disease.
Frequently Asked Questions (FAQ):
Can Newcastle Disease affect Humans:
Yes and No. Exposure to infected birds such as in a poultry processing plant or farm can lead to influenza like symptoms like wheezing, mild cold and coughing. Some extreme cases have led to conjuctivitis according to some studies. However, They are not hazardous to human health and cannot lead to death