Author
King, Daniel |
Submitted to: Merck Veterinary Manual
Publication Type: Book / Chapter Publication Acceptance Date: 8/6/2002 Publication Date: 1/17/2005 Citation: King, D.J. 2005. Newcastle disease. In: Kahn,C.M., Line,S., editors. The Merck Veterinary Manual. 9th edition. Whitehouse Station, NJ: Merck & Co., Inc. p.2255-2257. Interpretive Summary: Not required for book chapter. Technical Abstract: Concise information about Newcastle disease (ND) is provided for a book that serves as a quick reference guide to the infectious, parasitic, metabolic, nutritional, and toxic diseases of domesticated animals and birds as well some exotic species that a veterinarian might encounter. Newcastle disease is an acute viral disease of domestic poultry and many other bird species. It is one of the most important diseases of poultry world wide and because so many bird species, including feral birds, can be infected commercial poultry are at risk to infection from many sources. ND is caused by an RNA virus. Different strains of ND virus range in virulence from those that produce high mortality in susceptible birds to those that cause mild or asymptomatic infections. The low virulence strains are widely used as live virus vaccines to prevent disease in poultry. Infected birds shed the virus in respiratory discharges and feces. The clinical disease varies in severity and the observed signs depend on whether the infecting virus has a predilection for the respiratory, digestive, and/or nervous systems. Remarkable gross lesions are only seen with hemorrhagic form of the disease, a disease form that must be differentiated from highly pathogenic avian influenza. Consequently the diagnosis must be confirmed by virus isolation and pathogenicity tests to determine the virulence of the virus. Newcastle disease virus can cause a transitory conjunctivitis in man, but the condition has been limited primarily to laboratory workers and vaccination teams exposed to large quantities of virus. |