Newcastle Disease (NDV): Clinical Pathotypes & Control
Scientific overview of Avian Paramyxovirus-1 pathology, symptoms, and vaccination schedules.
Scientific Overview
Newcastle Disease is a highly contagious viral disease affecting domestic and wild bird species globally. Caused by virulent strains of Avian Paramyxovirus-1 (APMV-1), it can manifest in viscerotropic (digestive hemorrhages) or neurotropic (nervous paralysis) pathotypes, causing up to 100% flock mortality.
Clinical Signs and Virulence Pathotypes
Strains are classified into three pathotypes based on severity: Velogenic (highly virulent, causing acute respiratory distress, torticollis/twisted necks, facial swelling, and rapid death); Mesogenic (moderate virulence, causing mild nervous signs and respiratory distress in young pullets); and Lentogenic (low virulence, subclinical respiratory infections used for live vaccine strains like Hitchner B1 and LaSota).
Visceral Lesions and Prophylaxis
Gross lesions of velogenic viscerotropic NDV include severe petechial (pinpoint) hemorrhages on the tips of the proventriculus glands, necrosis/ulceration of Peyer's patches in the intestine, and hemorrhagic cecal tonsils. Control relies on strict biosecurity to exclude vector wild birds, and live/killed vaccination schedules to establish mucosal and circulating antibodies.