Newcastle Disease is a highly contagious viral infection that affects common species of domesticated and wild birds.
The birds that are susceptible to Newcastle Disease include chickens, ducks, pheasants, partridges, guinea fowl and other wild and captive birds, including ratites such ostriches, emus and rhea.
The disease may lead to clinical signs like digestive, respiratory and nervous, which, may include respiratory disease, depression, prolific diarrhoea, decrease in egg production among layers, and twisted necks, if the affected birds survive. Extreme forms of Newcastle disease are highly dangerous.
Humans are rarely badly affected by Newcastle Disease. However, people who have come into contact with infected birds may develop an eye infection. This infection normally goes away without treatment.
This disease affects birds of all ages.
Causes of Newcastle Disease
This disease is caused by a paramyxovirus that can exist in pathogenicity from slight to highly pathogenic. Basically, that means that if your flock get Newcastle Disease, it might be a slight infection, or it may be fatal.
The virus is usually spread when a healthy bird comes into physical contact with an infected bird. The virus can also be found in chicken droppings (manure) and is released into the air.-This is the same air that the birds breathe.
Carcasses, water, food, contaminated equipment, and clothing are also other sources of infection. The virus is not as dangerous to humans as it is to birds, but it can cause conjunctivitis (eye infection) in human beings.
Signs and Symptoms of Newcastle Disease
The clinical signs in affected birds can vary. The disease can be present in a very acute form with sudden onset and high mortality, or as a mild disease with respiratory distress or a drop in egg production as the only detectable clinical signs. A sub-clinical (asymptomatic) form of Newcastle disease and many intermediate forms of the disease can also occur. The main signs are:
- Hoarse chirps (in chicks)
- Watery discharge from nostrils
- Laboured breathing (gasping)
- Twisting of the neck (a sign of Central Nervous System involvement)
- Decreased feed and water consumption
- Reduced egg production
As you can see, these signs and symptoms may also relate to numerous other issues that chickens may have.
Prevention and Treatment of Newcastle Disease
Newcastle Disease has no treatment, once a bird is infected. However, treatment with antibiotics to prevent secondary infections may help. This would mean treating all healthy birds with the antibiotic.
It is important to note that the virus can survive and remain alive for up to 2 months in manure and up to 12 months in carcasses. Therefore it is vital that dead birds are cleared away, and coops are kept clean.
The Newcastle Disease virus is easily killed by disinfectants, direct sunlight, and fumigation. Spraying a disinfectant in coops, and on perches will kill the Newcastle Disease.
The best method of prevention, is to ensure that you have strict biosecurity measures in place. This will help with other diseases as well, including Bird Flu.
If you think you have an infected bird, you should isolate them as soon as possible, and any birds they have come into close contact with.