RESUMO
Fasciolais a well-known parasite with a worldwide distribution and huge implications for the economic performance of domesticated herbivorous animals. It also caused deleterious effects on human health. It is prevalent in most parts of Iran, but especially in Gilan province. During 2005, 445 fecal samples taken directly from the rectum of local cattle in three different regions of Gilan and were subjected to coprological examination using saturated zinc and sodium chloride solution. The sex, age and locality of cattle were recorded. Our findings revealed an overall infection rate of 32% with the highest rate [55.2%] occurring in Talesh. No significant relationship was found between sex or age [P=0.65] and infection. Despite this, in contrast to the longheld assumption that adult cattle develops resistance to infection, our findings showed no difference between the rates of infection and the mean number of Egg Per Gram [EPG] in young and old cattle. The rate of infection in 5,820 slaughtered cattle showed that the fascioliasis is more prevalent among the animals examined in Talesh Region [P<0.01]. Meanwhile, there was a direct relationship between the amount of rainfall and the rate of infection [r=0.98, P<0.01]. The determination of Fasciola species in the liver of 70 native cattle revealed that 50 [71.4%] harbored F. gigantic, 14 [20%] had F. hepatica, and six [8.5%] had F. hepatica and F. gigantica. Therefore, F. gigantica was the dominant species in the studied areas