histopathological features of ornithodoros lahorensis bite on rat

background: besides of transmitting several diseases to animals, and tick paralysis, ornithodoros lahorensis induce skin lesions. this experiment was done to determine histopathological features of adult o. lahorensis bite on rat. methods: in this investigation adult male rats were infested with o. lahorensis ticks. animals were divided into two groups and euthanized two days and two weeks after infestation. the skin samples were fixed in 10% buffer formal saline and processed and sections were stained with hematoxylin & eosin. results: the lesions reflected the clinical and gross findings, with hyperemia, edema and vacuolation in the early stages, cellular infiltrations, principally lymphocyte accompanied vascular changes. newly formed fibrous tissue with large number of hyperemic capillaries and active inflammatory process in which lymphocytes and eosinophils were the predominant cells, were seen after two weeks. foci of necrosis in the epithelium with remnant of infiltration of polymorphonucular cells with sever hemorrhages were also evident. vascular changes included prevascular infiltration of lymphocyte and fibrinoied ne­crosis on the vessel walls. conclusion: this study well documented the different pathological changes of skin of rats with o. lahorensis.