Paramyxovirus 1 or Newcastle Disease is a highly contagious viral disease affecting poultry of all ages. Affected species include chickens, turkeys, pigeons and ducks. The condition is rarely diagnosed in ducks but is a possible cause of production drops/fertility problems. Other species can be infected including mammals occasionally (e.g. conjunctivitis in man). The virus involved is Paramyxovirus PMV-1, which is of variable pathogenicity. Signs are typically of disease of the nervous, respiratory or reproductive systems. Morbidity is usually high and mortality varies 0-100%. Higher mortality is seen in velogenic disease in unvaccinated stock. - sometimes called 'asiatic' or exotic. It is highly virulent for chickens, less for turkeys and relatively apathogenic in psittacines. ND - Neurotropic Velogenic - Acute and fatal in chickens of any age causing neurological and some respiratory signs. Intestinal lesions are absent. ND - Mesogenic - Mortality and nervous signs in adult. These viruses have sometimes been used as vaccines in previously immunised birds. ND - Lentogenic - Mild disease, sometimes subclinical. Can affect any age. Strains can be developed as vaccines. Transmission is via aerosols, birds, fomites, visitors and imported psittacines (often asymptomatic). It is not usually vertical (but chicks may become infected in hatcheries from contaminated shells). The virus survives for long periods at ambient temperature, especially in faeces and can persist in houses (in faeces, dust etc). for up to 12 months. However it is quite sensitive to disinfectants, fumigants and sunlight. It is inactivated by temperatures of 56°C for 3 hours or 60°C for 30 min, acid pH, formalin and phenol, and is ether sensitive.

Signs

Signs are highly variable and will depend on the nature of the infecting virus (see above), the infective dose and the degree of immunity from previous exposure or vaccination.

Sudden Death Depression.

Inappetance.

Coughing.

Dyspnoea.

Diarrhoea.

Nervous signs.

Paralysis.

Twisted neck.

Severe drop in egg production.

Moult.

Treatment

None, antibiotics to control secondary bacteria.

Prevention

Quarantine, biosecurity, all-in/all-out production, vaccination. Use of Mycoplasma gallisepticum free stock under good management reduces the risk of vaccinal reactions.

Information taken from the poultrysite.