Clinical and gross-pathological changes in Muscovy ducks and Nigerian local chickens infected with Newcastle disease virus (XIVb strain)

摘要

Newcastle disease (ND) is an acute highly contagious viral disease, spreading rapidly within flocks and affecting birds of all ages. Muscovy ducks, geese and other anseriforms have been tested against different strains of Newcastle disease virus (NDV) and are found to be potential reservoirs showing mild or no clinical signs when infected experimentally with strains that are virulent to chickens. The aim of this work was to compare the clinical and gross pathological changes in Nigerian local chickens and Muscovy ducks experimentally infected with XlVb strain of Newcastle disease virus. Forty birds consisting of 20 chicks and 20 ducklings were randomly selected and divided into 4 groups of 10 birds each. The Groups were designated as group 1 (infected chicks, IC), group 2 (control chicks, CC), group 3 (infected ducklings, ID), group 4 (control ducklings, CD). Groups 1 and 3 were inoculated orally with 107.8/ 0.1ml /bird as the embryo lethal dose (ELD50/ml) of the NDV (XIVb) strain. Clinical signs observed were inappetance, sitting on hock, diarrhoea, depression and death which were severe in infected chicks but mild in infected ducklings. Gross pathological findings were severe congestions and haemorrhages in most of the lymphoid and other visceral organs of the IC compared to the ID. Muscovy ducks could serve as a source of the ND caused by strain XIVb to the local chickens while suffering mild form of the disease. It is recommended that mixing of Muscovy ducks and domestic chickens in the villages by poultry farmers should be discouraged.