Comparative Evaluation of the Effects of Velogenic Newcastle Disease Virus Infection on the Hematology of Ducks and Chickens

摘要

The hematological lesions consequent upon velogenic Newcastle disease virus (NDV) infection were investigated in 6-week-old ducks and chickens. Following intramuscular inoculation, the results indicated significantly lower (p < 0.05) packed cell volume (PCV) in infected chickens (IC) on days 3 - 9 post inoculation (PI) and in infected ducks (ID) on days 3 - 15 PI. The hemoglobin concentrations were significantly lower (p < 0.05) in IC on days 3, 6 and 15 PI while in the ID, they were significantly lower (p < 0.05) on days 3, 9 and 15 PI. The total erythrocyte counts were significantly lower (p < 0.05) in IC on days 3, 9 and 15 PI and in ID, they were significantly lower (p < 0.05) on days 3 and 9 PI. The mean corpuscular values indicated macrocytic hypochromic anemia in IC and macrocytic normochromic anemia in ID. The leucogram showed leucopenia in IC and initial leucopenia followed by leucocytosis in ID. The hematological pictures of the velogenic NDV in this experiment indicate less susceptibility of ducks when compared with the chickens. The severity of this virus infection in chickens and the mild clinical signs and lesions presented by ducks showed that ducks are far less susceptible than chickens.