A Study on Prevalence, Morphology and Morphometric of Gongylonema pulchrum in Sheep Slaughtered in Sari, Northern Iran

Background and Aims: The genus Gongylonema infects the upper digestive tract of birds, mammals, and humans. Livestock parasites, especially in the gastrointestinal tract, have caused irreparable damage, including death, reduced products, and economic losses. The present study aimed to reveal the prevalence and morphological and morphometric study of Gongylonema spp. isolated from the esophagus of slaughtered sheep in Sari, northern Iran. Materials and Methods: Esophagi of 340 sheep were collected from Sari's industrial slaughterhouse during the summer and autumn of 2021 (summer=115, autumn= 225). After longitudinal cutting, the surfaces of the esophageal mucosa were carefully checked under the light. The prevalence of infection was estimated, and the morphometric and morphological characteristics of the isolated worms were investigated using a calibrated light microscope and camera lucida. Results: The prevalence of infection was 7.6% (26 isolates), which was estimated for summer and autumn 12 out of 115 (10.4%) and 14 out of 225 (6.2%), respectively. A comparison of morphological features of nematodes in this study with Gongylonema morphological criteria showed that all of them were Gongylonema pulchrum. Conclusions: In the present study, a moderate gongylonemiasis infection was estimated in the sheep from Sari's industrial slaughterhouse. Morphological examination of the retrieved worms showed characteristic morphologies of Gongylonema pulchrum. To clarify the status of the infection, several morphological and molecular studies should be performed on different types of intermediate and final hosts of the parasite in different parts of the country.