Virulent Newcastle disease (VND), formerly exotic Newcastle disease, is a contagious viral avian disease affecting many domestic and wild bird species; it is transmissible to humans. Though it can infect humans, most cases are non-symptomatic; rarely it can cause a mild fever and influenza-like symptoms and/or conjunctivitis in humans. Its effects are most notable in domestic poultry due to their high susceptibility and the potential for severe impacts of an epizootic on the poultry industries. It is endemic to many countries. No treatment for VND is known, but the use of prophylactic vaccines and sanitary measures reduces the likelihood of outbreaks.

Poultry are domesticated birds kept by humans for the purpose of harvesting animal products such as meat, eggs or feathers. The practice of raising poultry is known as poultry farming. These birds are most typically members of the superorder Galloanserae (fowl), especially the order Galliformes. The term also includes waterfowls of the family Anatidae but does not include wild birds hunted for food known as game or quarry.