Tehran University of Medical Sciences Journal of Arthropod-Borne Diseases 2322-1984 11 3 2017 10 08 441 445 EN Seyed Mohammad Hoseini Department of Pathobiology, Babol Branch, Islamic Azad University, Babol, Iran Bahram Ali Zaheri Department of Environmental Protection Semnan, Semnan, Iran Mohamad Ali Adibi Department of Environmental Protection Semnan, Semnan, Iran Hooman Ronaghi Department of Microbiology, Faculty of Specialized Veterinary Science, Science and Research Branch, Islamic Azad University, Tehran, Iran Amir Hossein Moshrefi Young Researchers and Elite Club, Babol Branch, Islamic Azad University, Babol, Iran 2017 09 12 2017 09 12 Background: The larval stages of Gasterophilus are obligate parasites in the gastrointestinal tract of equine account­able for pathologic ulcers in the Persian onager gastrointestinal. The aim of the current report was to study the histo­pathological change with G. pecorum larvae in the esophagus of a Persian onager. Methods: This study was performed in Iranian Zebra propagation and breeding site in Khartouran National Park, southeast of Shahrud City, Semnan Province, Iran in 2014. Following a necropsy with specific refer to esophagus of one adult female Persian onager were transmitted to the laboratory. After autopsy, parasites collected from the esophagus were transmitted into 70% alcohol. For histopathological investigation, tissue samples were collected from the esophagus. The tissues were fixed in 10% buffered formalin, and conformity routine processing, there were stained with Hematoxylin and eosin. Results: After clarity by lactophenol parasites were identified as G. pecorum. Microscopic recognition contained hyperemia, inflammatory cell infiltration, epithelial destruction, esophageal gland hyperplasia. Conclusion: This is the first survey of G. pecorum and histopathological study in the Persian onager esophagus in the world. https://jad.tums.ac.ir/index.php/jad/article/view/720 https://jad.tums.ac.ir/index.php/jad/article/download/720/352