Popis: |
Exotic Newcastle disease (also known as velogenic viscerotropic Newcastle disease, Asiatic Newcastle disease, and Doyle's form of Newcastle disease) is a virus disease affecting domestic poultry and other avian species. It is that form or expression of Newcastle disease which is characterized by the causative virus having high lethality and an affinity for visceral organs, especially the digestive tract (Walker et al. 1973). Observed almost invariably in victims are hemorrhagic lesions and necrotic areas on the mucosal surface of the various subdivisions of the intestinal tract, especially the cecal tonsils, proventriculus, and Peyer's patches. Edema of the tissue along the trachea and near the thoracic inlet is also observed frequently. Susceptible chickens, artificially infected, die in 5–7 days with virtually 100 percent mortality. |