Hydrocephalus in Neonatal Rabbits Caused by Reovirus

Reovirus was isolated from commercial rabbit colonies in farms at KafrElsheikh and El-Gharbia Governorate with a history of neonatal hydrocephalus and blindness. The affected neonates exhibited hydrocephalus at age from 3-20 days with seasonal incidence at a late summer and early autumn (August, Sept. and Oct.). The gross lesions observed at necropsy were bulging of the skull, collapse of the cerebral hemispheres and replacement of the parenchyma by colorless, transparent cerebrospinal fluid (CSF). Virus isolation was conducted through chorio-allantoic membrane (CAM) of embryonated chicken eggs. Identification of the virus by electron microscope revealed presence of virion particles having a morphological appearance of Reovirus. Serological tests were also conducted. The pathogenicity of isolates was studied at different ages of rabbits. Histopathological examination of naturally and experimentally infected rabbits revealed marked loss of neurons, sever oedema with dilatation of brain ventricles, degeneration and desquamation of ependymal cells, Eosinophilic intracytoplasmic inclusion bodies were formed in infected CAM of embryonated chicken eggs. This is the first report of isolation of reovirus from neonatal rabbit affected with hydrocephalus.