Post mortem lesions include sacculitis, tracheitis and petechia on the serous membranes. The proventricular mucosa is frequently haemorrhagic with necrotic plaques. In birds infected with the less virulent strains of NDV the lesions may be restricted to congestion of the respiratory tract. | Post mortem lesions include sacculitis, tracheitis and petechia on the serous membranes. The proventricular mucosa is frequently haemorrhagic with necrotic plaques. In birds infected with the less virulent strains of NDV the lesions may be restricted to congestion of the respiratory tract. |