Newcastle disease in imported psittacine birds.
D000818:Animals; D002642:Chick Embryo; D006470:Hemorrhage; D007886:Legislation, Veterinary; D009521:Newcastle Disease / Q000453:epidemiology*; D011563:Psittaciformes; D012846:Singapore; D014132:Trachea / Q000473:pathology; D006113:United Kingdom