Introduction What Are the Clinical Signs?

Exotic Newcastle disease (END) is a contagious

and fatal viral disease affecting all species of

birds. Previously known as velogenic viscerotropic Newcastle disease (VVND), END is

probably one of the most infectious diseases of

poultry in the world. END is so virulent that

many birds die without showing any clinical

signs. A death rate of almost 100 percent can

occur in unvaccinated poultry flocks. END can

infect and cause death even in vaccinated

poultry.

In 1971, a major outbreak occurred in commercial poultry flocks in southern California.

The disease threatened not only the California

poultry industry but the entire U.S. poultry and

egg supply. In all, 1,341 infected flocks were

identified, and almost 12 million birds were

destroyed. Eradication efforts cost taxpayers

$56 million ($228 million in 2002 dollars),

severely disrupted the operations of many

producers, and increased the prices of poultry

and poultry products to consumers.

END affects the respiratory, nervous, and digestive systems. The incubation period for the

disease ranges from 2 to 15 days. An infected

bird may exhibit the following signs:

• Respiratory: sneezing, gasping for air, nasal

discharge, coughing

• Digestive: greenish, watery diarrhea

• Nervous: depression, muscular tremors,

drooping wings, twisting of head and neck,

circling, complete paralysis

• Partial to complete drop in egg production

• Production of thin-shelled eggs

• Swelling of the tissues around the eyes and in

the neck

• Sudden death

The death rate in END-infected flocks goes up

drastically.

Figure 1—An outbreak of END today would severely impact

the U.S. poultry industry.

How Does END Spread?

END is spread primarily through direct contact

between healthy birds and the bodily discharges

of infected birds. The disease is transmitted

through infected birds’ droppings and secretions

from the nose, mouth, and eyes. The disease

spreads rapidly among birds kept in confinement, such as commercially raised chickens.

High concentrations of the exotic Newcastle

virus are in birds’ bodily discharges; therefore,

the disease can be spread easily by mechanical

means. Virus-bearing material can be picked up

on shoes and clothing and carried from an

infected flock to a healthy one. The disease is

often spread by vaccination and debeaking

crews, manure haulers, rendering-truck drivers,

feed- delivery personnel, poultry buyers, egg

service people, and poultry farm owners and

employees.

The virus that causes END can survive for

several weeks in a warm and humid environment on birds’ feathers, manure, and other

materials. It can survive for extremely long

periods in frozen material. However, the virus is

destroyed rapidly by dehydration and by the

ultraviolet rays in sunlight.

Smuggled pet birds, especially Amazon

parrots from Latin America, pose a great risk of

introducing END into U.S. poultry flocks. Amazon parrots that are carriers of the disease but

do not show symptoms are capable of shedding

exotic Newcastle virus for at least 400 days.

How Can Poultry Producers

Help Control and Prevent END?

The only way to eradicate END from commercial poultry is by rapidly destroying all infected

flocks and imposing strict quarantine and

verifying controls with indepth surveillance

programs. Poultry producers should strengthen

biosecurity practices to prevent the introduction

of the disease to their flocks. Biosecurity is also

important to protect backyard and hobby flocks.

The following are tips on proper biosecurity

practices:

• Permit only essential workers and vehicles on

the premises.

• Provide clean clothing and disinfection

facilities for employees.

• Clean and disinfect vehicles (including tires

and undercarriages) entering and leaving the

premises.

• Avoid visiting other poultry operations.

• Maintain an “all-in, all-out” philosophy of flock

management with a single-age flock.

—Control the movement of all poultry and

poultry products from farm to farm.

—Do not “skim” mature birds from a flock for

sale to a live-poultry market.

—Clean and disinfect poultry houses between each lot of birds.

• Do not keep pet birds on the farm. Employing workers who own pet birds exposes your

poultry to increased disease risk.

• Exclude vaccination crews, catching crews,

and other service personnel who may have

been in contact with other poultry operations

within 24 hours.

• Protect flocks from wild birds that may try to

nest in poultry houses or feed with domesticated birds.

• Control movements associated with the

disposal and handling of bird carcasses, litter,

and manure.

• Take diseased birds to a diagnostic laboratory for examination.

Figure 2—Chickens with END exhibit signs of depression

and respiratory distress.

Figure 3—Twisting of the neck is one of the signs birds may

show when END has affected their nervous system.

Figure 4—Another symptom of END is the inability to perch

or fly, as shown in this picture of an affected parakeet.

Figure 5—Hemorrhages in the postmortem lesions of the

trachea, intestine, and gizzard (stomach) of a chicken (from

left to right) verify the presence of END.

Figure 6—A biosecure broiler house protects poultry flocks

from coming into contact with wild or migratory birds.
Exotic

Newcastle

Disease

A Deadly Disease That Affects

Poultry and Pet Birds

United States Department of Agriculture

Animal and Plant Health Inspection Service

Program Aid No. 1739

How Can Pet-Bird and BackyardPoultry Enthusiasts Help Control

and Prevent END?

What Is the Animal and Plant Health

Inspection Service’s (APHIS) Role?

To prevent END from being introduced into U.S.

poultry flocks, USDA–APHIS requires that all

imported birds (poultry, pet birds, birds exhibited

at zoos, and ratites) be tested and quarantined

for diseases before entering the country.

In addition to international import restrictions,

APHIS has increased surveillance efforts to

detect END if it is accidentally introduced into

the United States. APHIS and State veterinarians trained to diagnose foreign animal diseases

regularly conduct field investigations of suspicious disease conditions. This surveillance is

enhanced by efforts from university personnel,

State animal health officials, USDA-accredited

veterinarians, and industry representatives.

If END is detected in domestic poultry or pet

birds, APHIS works quickly with its State and

industry counterparts to implement aggressive

measures, including quarantine, control, and

cleanup, to prevent opportunities for the disease

to spread.

Any poultry or pet-bird owners or veterinarians

who suspect a bird may have END should

immediately contact State or Federal animal

health authorities.

For more information, contact:

USDA, APHIS, Veterinary Services

Emergency Programs

4700 River Road, Unit 41

Riverdale, MD 20737–1231

Telephone (301) 734–8073

Fax (301) 734–7817

E-mail: emoc@usda.gov

or visit the APHIS Web site at

http://www.aphis.usda.gov.

How Can Suspicious Cases

Be Reported?

END is also a threat to the caged-bird industry

and poultry hobbyists. Birds illegally smuggled

into the United States are not quarantined and

tested by the U.S. Department of Agriculture

(USDA) and therefore may carry the exotic

Newcastle virus. Owners of pet birds should

• Request certification from suppliers that birds

are legally imported or are of U.S. stock, are

healthy prior to shipment, and will be transported in new or thoroughly disinfected

containers.

• Maintain records of all sales and shipments

of flocks.

• Isolate all newly purchased birds for at least

30 days.

• Restrict movement of personnel between

new and old birds.

Amazon parrots are difficult to raise domestically. Anyone who is offering to sell a large

number of young parrots should be suspected

of smuggling or purchasing smuggled birds.

The U.S. Department of Agriculture (USDA) prohibits

discrimination in all its programs and activities on the basis of

race, color, national origin, sex, religion, age, disability, political

beliefs, sexual orientation, or marital or family status. (Not all

prohibited bases apply to all programs.) Persons with

disabilities who require alternative means for communication

of program information (Braille, large print, audiotape, etc.)

should contact USDA’s TARGET Center at (202) 720–2600

(voice and TDD).

To file a complaint of discrimination, write USDA, Director,

Office of Civil Rights, Room 326–W, Whitten Building, 1400

Independence Avenue, SW, Washington, DC 20250–9410 or

call (202) 720–5964 (voice and TDD). USDA is an equal

opportunity provider and employer.

Issued March 2003

This publication supersedes Program Aid 1414, Exotic

Newcastle Disease: A Deadly Form of a Familiar Poultry

Disease, which was published January 1992.

Figure 8—If END were detected in U.S. poultry, measures

such as quarantine, control, and cleanup would be implemented to prevent opportunities for the virus to spread. Figure 7—Birds illegally smuggled into the United States are

not quarantined and tested by the USDA and therefore may

carry the exotic Newcastle virus.

Photo credits:

Photographs come from the APHIS image

collection.