Results: The results of comparing showed that nucleotide sequences of small liver fluke samples in dogs, cats and metacercaria in Carassius spp. were similar to their corresponding ITS-2 amplicons and homology was very high, up to 99.9 - 100% with Opisthorchis viverrini species in the gene bank (Code MG797538 in Mianmar; AF408147 in South Korea; AY584735 in Thailand).