Fishborne zoonotic trematodes (FZT) are endemic in humans and cultured fish in Vietnam
but little is known about FZT in domestic animals. A study was designed to determine
FZT prevalence and species diversity, and risk factors for infection, in dogs, cats
and pigs. Faecal samples from 186 dogs, 94 cats and 168 pigs belonging to 132 households
in Nghia Hung district, Nam Dinh province, were examined for small trematode eggs;
those were trematode eggs with length less than 50 microm. Prevalence of FZT varied
significantly between cats (70.2%), dogs (56.9%) and pigs (7.7%). Forty-nine of the
egg-positive animals (25 dogs, 20 cats and 4 pigs) were necropsied to obtain adult
trematodes for identification. The liver fluke, Clonorchis sinensis, and 11 species
of intestinal flukes including Haplorchis, Stellantchasmus, Stictodora and Centrocestus
were recovered from the infected animals. The practice of feeding raw fish to the
animals was a significant risk factor for infection; this risk was reduced if the
animals were periodically treated with anthelmintics. Based on the high prevalence
of FZT and certain risky husbandry practices, domestic animals are likely to be major
contributors of FZT eggs to the environment. Therefore, education of farmers to avoid
feeding raw fish and to perform regular anthelmintic treatment of dogs, cats and pigs
is needed in integrated FZT control programs.