Newcastle disease (NCD) is feared world-wide for its ability to cause huge losses in poultry businesses, right from the smallest backyard operation to intensive, commercial poultry farms.
The highly contagious and deadly virus spreads like lightning where chickens are housed in enclosed spaces. It moves throughout and spreads regionally through long distance transport of birds. Virtually anything that has been in an infected environment can spread NCD – chickens, people, equipment, products, contaminated clothing, boots, feed trucks, vehicles from infected farms. The virus has a robust nature and can survive outside the chicken for long periods.
Sick chickens and carrier chickens contaminate feed and water through their droppings and pass the virus onto healthy chickens when they ingest food and water.
The pathogen is also spread through airborne droplets that enter the systems of healthy chickens when they breathe. It can stay viable in chicken houses for up to 12 months.
SIGNS OF NCD
Chickens become weak and may die without showing any symptoms. Signs of NCD depend on the affected body part whether this is the airways, gut or nervous system.
Signs may be depression; lack of appetite; coughing; breathing difficulty; green diarrhoea; nervous signs such as walking in circles, walking with difficulty, shaking; paralysis; a twisted neck; drop in egg production; ruffled feathers and feather loss.
Post mortem can show bleeding in the gut, small red spots on fat around the heart and intestines, red windpipe with red spots and watery nose and sinus contents. Post mortems can also come up clean with no signs of NCD. In this case lab tests are the only way of confirming the presence of the virus.
PREVENTION
The only way to control NCD is to prevent it. To stop the disease from spreading, destroy the sick chickens, burn chicken litter and dead chickens and disinfect all housing. Quarantine your farm or your backyard operation, do not allow foot or vehicle traffic through the area.
Indigenous chickens in good condition have a better chance of resisting NCD. Protect your flocks through good management and protect them with a vaccine protocol that uses a combination of live and killed vaccines.
Dr Moosa Ameen, Zambian vet, suggests the easiest route is to vaccinate through the drinking water. Eye-drop vaccination is also effective but more difficult and time-consuming.
Intervet’s (MSD animal health) range of Nobilis vaccines offers cover for day-olds, broilers and layers.
For more information contact Dr Moosa Ameen, Lusaka based, Agrivet Africa, tel: +260 1288823
