A total of 1920 ducks from Binh Dinh, Phu Yen and Khanh Hoa provinces were examined by post-mortem method in order to study epidemiology of small liver fluke in ducks. The results showed that small liver flukes were only detected in Binh Dinh province with 19.31%. The prevalence of liver flukes in ducks in Tuy Phuoc, Phu My, An Nhon, Phu Cat districts (plain region) were higher than that in An Lao, Van Canh districts (mountainous region). Ducks raised in semi-intensive and intensive systems had

more »

... the infected rate of 20.28% and 18.22 %; respectively (P>0.05). Ducklings from 1 day to 8 weeks old were not detected to have any liver flukes. However, the infectious rate of liver flukes in replacement ducks (9-24 weeks old) and in layer ducks (over 24 weeks old) was 11. 22% and 32.12%; respectively (P<0,05). The results of morphological examinations demonstrated that all morphological traits of the small liver fluke of ducks were clearly compatible with Opisthorchiidae family, Opisthorchis paragenimus species.