Abstract

Aim: The study evaluates the pathogenic potential of strain XIV.2 NDV in geese and guinea fowls experimentally.
Methods: Forty birds, comprising 20 geese and 20 guinea fowls, aged seven weeks were randomly divided into four groups (A–D), kept in separate pens as follows: 10 Control geese, 10 Infected geese, 10 Control guinea fowls and 10 Infected guinea fowls. The birds in group B and D were inoculated with 0.2 mL of strain XIV.2 NDV inoculum (titre of 108.2/0.1 mL ELD50) intra-nasally, while those in group A and C were inoculated with phosphate buffered solution (PBS) intra-nasally respectively. Gross and histopathological procedures were performed using standard methods.
Results: Revealed transient clinical signs without mortality in infected geese whereas moderate clinical signs with mortality were observed in infected guinea fowls. Gross lesions were mild in infected geese from 6 to 28 days post-inoculation, (dpi) and in infected guinea fowls at 3, 21 and 28 dpi, with moderate lesions observed from 6, 11, 12 and 14 dpi. Histopathological lesions in infected geese were moderate from 3 to 21 dpi, but mild at 28 dpi, whereas mild lesions were observed from 3 to 6 dpi, followed by moderate lesions from 9 to 28 dpi in infected guinea fowls.
Conclusion: Morbidity and mortality due to strain XIV.2 NDV infection were moderate in guinea fowls, but inapparent and transient in geese. Therefore, free-ranging system commonly practice in the region should either be discouraged or vaccination of these species of birds should be encouraged.

Key words: Newcastle disease virus; pathogenesis, strain XIV.2; virulence; geese; guinea fowls