Recognising avian notifiable diseases 2. Newcastle disease

Newcastle disease, in common with avian influenza, is a highly infectious transboundary avian notifiable disease that is subject to internationally recognised definitions, as described by the World Organisation for Animal Health (OIE) and legislation for the purposes of maintaining poultry health, trade and disease control. This article, the second in a three-part series on avian notifiable diseases, discusses the biology of Newcastle disease virus, as well as the statutory definitions and epidemiology of disease. In addition, it describes key clinical and pathological features of Newcastle disease in different poultry hosts. Avian influenza was similarly described in Part 1 of this series, which was published in the September issue of In Practice (vol 35, pp 426-437). Part 3 will be published in the November/December issue of In Practice and will discuss the investigation of poultry health problems with reference to avian notifiable diseases and differential diagnoses.