Pathological Studies Of Rabbit Hemorrhagic Disease (RHD)

Rabbits were inoculated with Y8504 stain of the rabbit hemorrhagic disease (RHD), and were dissected after their death. Formalin-fixed tissues of the cerebrum, heart, lung, pancreas, kidney, adrenal gland, small intestine and stomach were studied using routine haematoxylin and eosin (HE) stain, different pathological changes and damages were found in different organs after infection. It indicates that RHDV can influence the coagulability of the blood, cause hypoxia and catholicity necrosis because of gross hemorrhage of some organs, ultimately lead to acute nonfunction of all the organs and death.Histopathologic changes of the nervous sytem were observed in 47 experimentally infected rabbits . Changes were seen in cns in nearly all cases.Most frequent lesions were nenous hyperemia,stasis and microthrombosis. Focal hemorrhage, micronecrosis and satellitosis were present in a few cases. The myelindegeneration and demyelination of nerve fibers occurred in the nervi ischiadicus in more than half of the cases.Authors regard these lesions as the hypoxic and dystrophic injury due to the ciriulatoyy disturbance rather than specific process. That is to say the cause of death was that the virus directly induced injury of different organs and vessel wall,then results in disseminated intravasvular coagulation(DIC) and systemic hemorrhage, and that blood loss caused hypoxia of systemic organs,and finally induced functional failure of vital important organs.According to the published VP60 gene of rabbit hemorrhagic disease virus(RHDV) two pairs of primers were designed for detecting RHDV by nested PCR assay. Firstly a 389 bp product was amplified and then used as template to perform the second amplification using the inner primers. With this nested PCR method, 12 RHD samples have been detected for RHDV and all got the positive results.