Histological lesions in central nervous system of sheep

Between January 05, 2003 and May 01, 2003 in Sanitary Veterinary Laboratory from Iaşi were examined 172 samples of brain tissue from sheep normally slaughtered for human consumption and from sheep whom slaughter were dictate by different reasons. Prior to the histopatological examination the samples were fixed in salty formalin solution 10%, included in paraffin, sliced by microtome at 5-6 μm and stained by modified HEA staining metod. The histopatological examination revealed various microscopic lesions: circulatory disorders of meninges and in nervous parenchyma (congestion, hemorrhages, edema, disseminated intravascular coagulation) in 70% of examined cases; dystrophies – 50% (vascular hyalinosis, granular or vacuolar dystrophy of perikarya, 8%, central and peripheral cromatolysis of neurons, neurophylus spongiosis, demyelination); necrobiotic lesions of neurons (neuronophagia, karyolysis, karyorexis) 70% of cases; meningeal and vascular metaplasia 5%; meningoencephalitis and encephalitis with variable degree of intensity (predominant lymphohistiocytic) 30-40%