Vol. 9, Special Issue 4, Part B (2024)

Author(s): R Ravikumar, J Selvaraj, T Lurthu Reetha, S Balakrishnan, R Thangathurai and D Basheer Ahamad

Abstract: The present study reports the occurrence of Lymphoproliferative diseases (LPDs) like Marek’s disease (MD), Lymphoid leucosis (LL) and Reticuloendotheliosis (RE) in nine layer chickens of 68 weeks age and the flock size was 50,000. The cumulative mortality from 51 to 68 weeks (18 wks) was 13%. Affected chicken showed weak, anorexia, paralysis, emaciation and 7%. egg production loss. Necropsy examination of suspected dead bird’s visceral organs like liver, spleen and kidney revealed enlargement and numerous greyish tumourous spots / foci on surface. Ovary revealed irregular grayish firm growths. Microscopic examination of liver, spleen, kidney and ovary sections revealed cells infiltration like pleomorphic lymphoid cell (PLC), lymphoblasts and reticular cells which is suggestive of lymphoproliferative diseases like MD, LL and REV.