The prevalence of F. gigantica often overlaps with that of Fasciola hepatica, and the two species are so closely related in terms of genetics, behaviour, and morphological and anatomical structures that distinguishing them is notoriously difficult.

[4] The lymnaeid intermediate hosts of F. gigantica are distinguishable from those of F. hepatica, both morphologically and as to habitat requirement.

The species of Fasciola can become adapted to new intermediate hosts under certain conditions at least based on laboratory trials.

[5][6] The Australian Lymnaea tomentosa (host of F. hepatica) was shown to be receptive to miracidia of F. gigantica from East Africa, Malaysia, and Indonesia.

[4] The parasite commonly infects cattle and buffalo, and can also be seen regionally in goats and sheep, and in nonruminants (donkeys).

[4] Despite the importance to differentiate between the infection by either fasciolid species, due to their distinct epidemiological, pathological, and control characteristics, unfortunately, coprological (excretion-related) or immunological diagnoses are difficult.