morphologic and morphometric variations of the adult and the eggs of frequent fasciola species from domestic ruminants of north west of iran

worldwide including iran, fasciola species are the causes of human and animal fasciolosis which have comparatively identical morphologies. the present study is aimed to identify different fasciola forms by using morphologic and morphometric variations from domestic ruminants of northwestern iran. a total of 130, 67 and 140 livers of cattle, water buffaloes and sheep respectively were collected from urmia slaughterhouse. the adult helminths were removed and stained using acetocarmine staining. the fasciola eggs were directly extracted from the uterus of adult helminths. the overall frequency of infection was 28.19%. the highest infection rate was found in water buffalos (34%). the highest number of helminth per each animal was recorded for cattle (9.23%). the predominant infecting fasciolid in the examined ruminants was f. gigantica (51.89%) from water buffaloes origin. there was a significant difference among the width (w), the length (l), and the distance between ventral sucker to the posterior end of the body (dbve) of all fasciola forms from the examined animals. the l of different fasciola forms had a significant difference for f. gigantica and intermediate form of fasciola from cattle and water buffaloes origins. the w and the proportion of the body length to the width (si) of eggs from all fasciola forms had no significant difference. the ls of eggs of f. hepatica and f. gigantica were significantly different. the results of this study elucidated three forms of fasciola co-existing in the ruminants of the region. additionally, the morphology and morphometry of adult and eggs of fasciola species within a range of hosts may be taxonomically informative and one of the character sets for discrimination of fasciolid forms.