SummaryTavassoli, M., R. Hobbenaghi, A. Kargozari & H. Rezaei, 2018. Incidence of Linguatula serrata nymphs and pathological lesions of mesenteric lymph nodes in cattle from Urmia, Iran. Bulg. J. Vet. Med., 21, No 2,[206][207][208][209][210][211] This study was aimed to determine the infection rates of mesenteric lymph nodes (MLNs) with Linguatula serrata nymphs and their pathological lesions. From November 2012 to June 2013, the MLNs of 104 cattle were randomly sampled in Urmia slaughterhouse, northwestern Iran. They were examined macroscopically and histopathologically. The infected and non-infected lymph nodes were processed for histopathology. They were examined under light microscope and observations were recorded. The results indicated that out of 104 sampled cattle, 63 (60.57%) were infected. Macroscopic examination revealed that the infected lymph nodes were swollen and dark, with rubbery consistency, some with subcapsular haemorrhages on cutting. The mean number of counted lymph node follicles in the nodes from healthy cattle at random microscopic levels was 18±2.8 (range 15-23), compared to 48.9±3.7 (range 44-57) in the infected nodes. Because L. serrata is a zoonotic parasite, preventive measures should be adopted to break the parasite's cycle and minimise the risk of infection in both humans and other animals.

Linguatula serrata (Pentastomida: Linguatulidae) known tong-worm is a cosmopolitan, zoonotic, and obligate endoparasite. The parasite lives in the nasopharyngeal region of the final hosts, which primarily include dogs and other carnivores. Various herbivores, including, camels serve as the best intermediate hosts for nymph stages. In present study the mesenteric lymph nodes of 101camels were examined for infection to L. serrata macroscopically and histopathologically. The infected and normal lymph nodes were processed for histopathology. The results indicated that out of 101 sampled 33 (32.67%) were infected. Macroscopic examination revealed that the infected lymph nodes are swollen and dark, with rubbery consistency, some with subcapsular hemorrhage on cutting. Extensive hemorrhage occurred in various parts of infected lymph nodes. A section of L. serrata parasite was observed near one of the hemorrhage centers. Neutrophil count was very high in these centers and giant cells were present around the parasite, indicating granulomatous reaction. Our findings confirmed that different regions of Iran is an endemic for L. serrata infections. Because L. serrata is a zoonotic parasite, preventive measures should be adopted to disrupt the parasite’s life cycle and minimize the risk of infection in both humans and other animals.