A study on histopathological changes due to zoonotic nematodes in sheep in Ilam province, Iran

Livestock has important role in the human life cycle. Humans along with livestock over the years have been accompanied by undesirable consequences like zoonotic diseases. Zoonotic infectious agents such as helminths are among the most prevalent causes for the major human emerging and re-emerging infections. So, this study was performed to identify the zoonotic gastrointestinal nematodes and determine histopathological changes occurred on gastrointestinal tract in Kurdish sheep slaughtered in Ilam industrial abattoir. For this purpose, tissue samples of 375 above mentioned sheep were checked strictly. As a result, identified nematode species were Ostertagia ostertagi, Haemonchus contortus, Trichostrongylus colubriformis, Trichuris globulosa, Oesophagostomum sp., Bunostomum sp. Histopathological findings of infected tissues, particularly lymph nodes and mesentery have been described in results detailed. Briefly, presence of black dot or black streak on serosa of intestine, mesentery, paleness and enlargement of mesenteric lymph node, decrease in the number and size of the lymphatic follicles, decrease in the lymphoid cell population in the medulla tissue, increase of lymph node capsule thickness and sever depletion in secondary lymph follicles associated with lymphadenitis which represented by proliferation of lymphocytes and infiltration of macrophage as well as hyperemia and congestion in cortex and medulla were considerable histopathological changes. Accordingly, given that these parasites have a direct life cycle, thus, lack of hygiene in farms where animals are kept leads to increased infection and it is necessary to pay more attention to this field.