Jayanthi, NJaisree, SBharathi, RKalai Selvi, GKarthik, KAnand Chitra, MSenthilkumar, TMAHarikrishnan, TJDhinakar Raj, GTANUVAS2020-03-102020-03-102020-02http://krishikosh.egranth.ac.in/handle/1/5810145141TNV_20thMVC_PP_Feb-2020_PA63Infectious bursal disease (IBD), an acute, highly contagious viral disease affects the immune system of young chickens, caused by infectious bursal disease virus (IBDV) belonging to the genus Avibirnavirus within the family Birnaviridae. Though heavy outbreaks are less it continues to lurk in Tamil Nadu. A brown layer chicken farm situated in Thiruvallur with a history of sudden death, clinically ill birds showing dullness and watery diarrhoea was presented for necropsy. The birds were vaccinated as per schedule for NDV. The farm had a stock of about five hundred birds of which there was a mortality percentage of 14.4 when the birds were presented for necropsy. Necropsy examination revealed severe hemorrhages in the breast and thigh muscles, pale liver mildly oedematous enlarged pale bursa with stray petechiae in the proventriculus. Molecular screening for viral and bacterial diseases revealed the presence of IBD by PCR and NDV by RT- PCR while it was negative for IB virus. E.coli could be detected in heart blood swab. Antibiogram revealed nil sensitivity among the antibiotics commonly used. It was intermediate sensitive to cefotaxime, amoxyclav, norfloxacin and ciprofloxacin and was resistant to gentamicin,sulphadimidine and tetracycline. Histopathological examination revealed lymphoid cell depletion in the bursa, lymphocytolysis and few cystic spaces. This case documents the presence of IBD infection in areas around Chennai. Infection of NDV as known was probably due to immunosuppression caused by IBDV as the flocks were vaccinated for NDV as per schedule.enVeterinary SciencePresentation