Histopathological & causation of paralytic syndrom in chicken in Egypt

One day old ebicks were experimentally inoculated interacer::~brally with 0.05 ml of 10-3 dilution of avianencephalCJJlyelitis CA.-E) embryo adapted strain. On the seventhday post ir~ection, infecteQ cbicks started to show symptoms o.fataxia7 tremors, paralysis of the legs. The number of chicks showing symptoms :”::l.c.reased gradually to be 75 % of the inoculated flocks.Different parts of the centrul nervous system (ONS) were examined for the most characteristic histopathologicalchE;ugeS. ThMse changes could be classified into three maintypes of: a) alterative. b) productive and c) inflammatory. Tbe alterative changes are characterized by pyknotic degene-ration? central chromatloysis and acute neuronal necrosis.The productive ahanges were mainly in the form of focal and jor diffuse gliosis 0 As for the in£~ammatory changes, they were manifisted ty vasculitis with lymphocytic vascularand perivascular infi.ltration. These main changes werenot seen with the same degree of intensity in the different parts of the O.N .S. The preclilict.ion sites were as follows.The molicul~r layer and the Purkinje cell layer of cerebe- llum ; nuclear group of mid brai~ Medulla oblongata, and the ventral horn of the spinal cord especially in the lumbosa- cral part.