The possible effect of drug resistance in hatching eggs of Fasciola spp. in cows of Ahvaz slaughterhouse

Objectives: Fascioliasis, caused by the common liver fluke Fasciola species, can be reduced considerably livestock productions and made serious health problems in some countries. Many factors are affecting the hatchability of Fasciola spp. eggs. The main factor cited in literatures, indiscriminate use of anthelminthic medicines specially benzimidazole derivatives against nematode, cestode and trematode infections which nowadays widely applied among local ranchers. Materials Methods: Eight fascioliasislivers were collected from naturally infected cows in Ahvaz slaughterhouse, Iran. Sexually mature Faciolagigantica removed from bile ducts, then after identification based on the standardized measurements in parasitology laboratory, the eggs wereextracted and collected at the bottom of cylinders. The eggs were finally transferred into a dark container containing normal saline and incubate for 14 days. Then the eggs were evaluated under light microscope. Results: The results showed that the mean rate of embryonated eggs in some eggs (37.5%) were 27.04% and rest of them containing miracidium or empty evacuated eggs while in some eggs (62.5%) mean rate of embryonated eggs were 71.91%. Conclusion: Only published reason for different hatching paths in some eggs would probably refer to drug- resistance. Recent studies have shown that different isolates of Fasciola species have distinct performance of hatching time due to drug-resistance.