Newcastle disease is an infection of domestic and other bird species with the virulent virus Newcastle disease in chickens (NDV). This is a worldwide problem, which is primarily an acute respiratory illness. With this disease, chickens can be depressed, behave nervously, such signs are most often characteristic of the clinical form. The severity depends on the virulence of the infecting virus and susceptibility.
Etiology and pathogenesis of the disease
Newcastle disease NDV and Newcastle disease virus, synonymous with serotype 1 avian paramyxovirus (PMV-1), is an RNA virus and the most important of the 11 known serotypes of PMV as a pathogen for poultry. Clinical manifestations range from high morbidity and mortality to asymptomatic infections.The severity of the infection depends on the virulence of the virus and age, immune status, and susceptibility.
Infected individuals can catch and carry the virus in expired air, respiratory discharges, and feces. The pathogen seeps during incubation , during the clinical stage and for a different, but limited period during recovery. The virus may also be present in eggs laid during the clinical form and in all parts of the carcass during acute infections.
Chickens are easily infected with Newcastle disease by ingesting contaminated water or food. Infected chickens and other domestic and wild birds can be sources of NDV. The movement of infected birds and the transmission of the virus, especially with infectious feces, movement of people and contaminated equipment or bedding, are the main methods for spreading viruses between herds. In any case, the panacea is a vaccine preventing Newcastle disease.
Symptoms of Newcastle disease in chickens
Always Newcastle disease in chickens occurs quickly and signs appear throughout the herd within 2 -12 days (average 5). The spread of Newcastle disease is slower if the fecal-oral route is the main means of transmission, especially for cellular birds. Newcastle disease in chickens and its symptoms mainly spread to young birds. Symptoms depend on whether the infecting virus is prone to the respiratory, digestive, or nervous systems.
Signs of Newcastle disease in domestic chickens
- Nerve tremors
- Paralyzed wings and legs
- Twisted necks
- Circulatory cramps
- Complete paralysis
In domestic chickens, respiratory symptoms with depression, greenish diarrhea and swelling of the head tissue can also be observed in some cases. Such symptoms are most characteristic of the virulent form of the disease. In chickens and young turkeys, when affected by Newcastle disease, various degrees of inadequacy may occur. In chickens, egg production most often ceases. Even if eggs are produced, they may be abnormal in color, shape or surface and have a watery protein. Mortality is variable, birds can die up to 100% of cases.
vaccinated birds if the vaccination against the strain was not on time may not show any signs of infection, except for a decrease in egg production, but these birds will shed the virus in saliva and feces . Poorly vaccinated birds can develop tortoiseshell. Also, ataxia or platelets 10-14 days after infection can be restored with maintenance therapy. How Newcastle disease of birds manifests itself in chickens can be viewed in more detail in the photo or video.
Treatment of chickens
When the Newcastle disease of chickens appeared, it is useless to treat them. Even after treatment for 1 year, chickens are considered a carrier of the virus.And as a result, products, that is, eggs and meat, are dangerous for consumption and sale. As a prophylaxis, the only effective remedy is vaccination. In fact, the vaccine is the cure for Newcastle disease. This vaccine is generally given to newborn chickens. The drugs are available for chickens, turkeys and pigeons and are used to induce a response to antibodies, therefore vaccinated applications must be exposed to a higher dose.
Unfortunately, ND vaccines do not provide sterile immunity. There is an instruction for each drug and it must be strictly adhered to. Mainly strain B1 and LaSota, is widely used and is usually introduced for poultry by mass application in drinking water or spray. Some farmers use a tool such as strain H virus vaccine to ensure the safety of their livestock. Alternatively, live vaccines are individually administered via the nostrils or conjunctival sac.
Chicken vaccination
Healthy chickens are vaccinated already on 1-3 days of life. Delaying vaccination until the second or third week prevents the interference of the maternal antibody with an active immune response. Mycoplasma and some other bacteria that damage the airways, if present, can act synergistically with some vaccines to aggravate its response after administration. The frequency of revaccination to protect chickens throughout life depends largely on the risk of infection.Accidental inoculation of human tissues with oil vaccines requires surgical treatment.
Recommendations for preventing the spread of the disease
In Newcastle disease, all NDV can lead to temporary conjunctivitis in humans, but the condition was limited primarily by laboratory workers exposed to a large number of viruses.Before poultry vaccination was widely practiced, conjunctivitis from NDV infection occurred in crews that worked with poultry in processing plants. The disease has not been reported in people planting poultry or consuming poultry products. If such viruses are detected at your facility, you must enter quarantine for a period of at least 30 days to resolve the condition in the house. The farmer should restrict the passage of unauthorized persons to the enterprise during quarantine.
Wear protective clothing and gloves to work with infected chickens. After working with infected chickens, it is necessary to completely disinfect the chicken coop , clothing, and equipment. If you managed to prevent the spread of the virus outside your house, then you need to adhere to the recommendations. You cannot sell the meat or eggs of birds diagnosed with Newcastle disease. the chicken coop should be completely disinfected; bedding should be replaced with new ones. If the perches are affected by feces and secretions of infected birds, they must also be changed.
Even after quarantine is removed, individuals remain under constant surveillance and are considered to be carriers of the Newcastle threat virus for some time.
In order not to make your company bankrupt, you should take all preventive measures to prevent such an infection. First of all, it is recommended to vaccinate chickens without fail.If you know that in a district within a radius of 10 km there is a poultry farm and an outbreak of Newcastle disease was recorded there, then chickens are vaccinated out of turn. After the vaccine has been formulated and a few weeks before it has been administered, the diet of the birds should be changed. You need to add more vitamins and varied foods to the daily menu to strengthen the immunity of chickens.
