Study on parasitic helminths infection in gastrointestinal tract and respiratory system of sheep in Gilan Province, northern Iran

In most of parasitic helminths infection in gastrointestinal (GI) and respiratory systems, mix infection plays important role. This study was aimed to determine parasitic helminths fauna of GI and respiratory systems using fecal examination and culture. A total of 140 fresh fecal samples were randomly collected from the rectum of examined sheep in different parts of Gilan Province in 2017-2018. A portion of each sample subjected for floatation and modified McMaster techniques. The intensity of infection estimated in term of eggs per gram of feces (EPG). Helminths identified based on eggs’ morphometric and morphologic characteristics. Third stage larvae (L3) and first stage larvae (L1) were collected using Baermann method and identified. Overall prevalence was 52.1% (73/140) with intensity of 196.62±9.94. The higest prevalence was found in Siahkal region (7.9%) in spring (39.3%). Helminths diversity was from trematodes (9.3%) (Fasciola hepatica (4.3%), Dicrocoelium dendriticum (5%)), cestodes (10%), and nematodes (52.1%). All infected sheep had mixed helminths’ eggs infections with two (15%) and three (2.9%) genus. Identified L3 of nematodes in GI was nine genus including of Ostertagia (4.3%, 2 species), Haemonchus sp. (1.4%), Trichostrongylus sp. (1.4%), Bunostomum sp. (2.1%), Strongyloides sp. (0.7%), Cooperia sp. (1.4%), Nematodirus sp. (2.1%), Chabertia sp. (1.4%) and Oesophagostomum sp. (2.9%). Identified L1 of lungworm (11.4%) was four species including of Dictyocaulus filaria (7.1%), Protostrongylus rufescens (2.1%), Cystocaulus ocreatus (1.4%) and Muellerius capillaris (0.7%). From the results, it was concluded that helminths infection of GI tract and respiratory system was prevalent in examined sheep of the region.