Paramyxovirus: New Castle Disease

Paramyxoviruses are enveloped RNA viruses that hemoglutinate red blood cells. Nine serotypes (PMV-1 – PMV-2) exist based upon the species or type of birds from which the virus was isolated and the location of isolation. PMV-1, 2, 3 and 5 can cause illness in psittacines.

Numerous strains of PMV-1 exist, some of which are very pathogenic and others of which are mildly pathogenic. An especially pathogenic strain is New Castle Disease virus (NDV)

Transmission

Infected bids shed NDV through their respiratory secretions and in their feces. Transmission is primarily through the feces, but inhalation of viral particles may occur as well as transmission by insects, wind, equipment and by contaminated hands and feet of people. Embryos may become infected if their shell is contaminated with the virus.

Incubation varies from 2 – 17 days depending upon the species of the bird, environment, concurrent infections, etc. Cockatiels, budgies, amazons, and cockatoos are highly susceptible to the disease. Other species such as lorys, macaws, canaries, finches, mynahs, and African greys may not show signs but may act as carriers.

Symptoms

Clinical signs may consist of depression, loss of appetite, lethargy, voluminous green diarrhea, dyspnea, nasal and ocular inflammation, ataxia, tremors, twisting of the head and neck, seizures and limb paralysis. Death may occur suddenly after the onset of a period of depression.

Diagnosis of NDV is by virus isolation. Tissues frequently examined include the trachea, lung, liver, spleen, pancreas and brain.

There is no treatment for Exotic Newcastle Disease. Prevent the disease through quarantining new birds and the use of biosecurity procedures.

Severe losses occurred during the twentieth century in the poultry industry in the United States as a result of NDV. At present, the disease has been eradicated through the initial strict regualtion of importation and eventual cessation of importation and captive breeding. Unfortunately, periodic outbreaks occur as a result of smuggled parrots – especially yellow napes and double yellowheaded amazons from Mexico and Central America.

Suspicion should be aroused if these birds are offered for sale at low prices or if no leg bands or poorly fitting leg bands are present.

If a bird showing signs of illness is found to be positive for NDV, all birds in the group must be destroyed.

PMV-1 New Castle Disease is a reportable disease to the federal government. The major concern is that a disease the United States has eliminated could be re-introduced and cause devestating illness and death to our poultry industry as well as to our pet bird and wild bird population.