Observation on occurrence of neural form of Marek's disease in desi chickens

Occurrence of Marek's disease (MD) was investigated in desi (Village) chickens. Clinically birds showed paralysis (lameness) of leg with typical posture of one leg forward and one leg backward, emaciation, torticollis, in-coordination, pale comb and wattle and paralysis of wing and neck with mortality ranged from 1% to 10 %. Necropsy examination of live sacrificed or dead birds revealed severe enlargement and edema of sciatic nerves with loss of cross striations and glistening appearance and atrophy of lymphoid organs. Histopathological examination of the nerve samples in most cases revealed focal cellular infiltration without any edema (type C nerve lesions) and intramural edema, infiltration by lymphocytes and plasma cells (type B nerve lesions) in few cases. Out of these eighteen farms investigated, concurrent infection of aspergillosis in two farms and colibacillosis and tapeworm infestation was observed in one farm each.