Incidence of Multiple Lymphoproliferative Diseases among Poultry Layer Birds in an Organized Farm in Central Kerala

Abstract

Ten birds of six months of age were taken as representative samples of an organized layer farm in Thrissur district of central Kerala having flock strength of 500, where unusual mortality (> 60%) was reported. All the birds belonged to the same batch and were vaccinated against commonly prevalent conditions like Marek’s disease and New castle disease. The dead birds were subjected to detailed postmortem examination in the Department of Veterinary Pathology, College of Veterinary and Animal Sciences, Mannuthy, Thrissur. On necropsy, six birds showed lymphoproliferative type of lesions in various visceral organs. The lesions consisted of either gross enlargement of the organs or focal white nodular masses on the surfaces which extended deep into the parenchymatous tissue. The tissues were subjected to histopathological and molecular investigations. With Hematoxylin and Eosin staining, the different tissues revealed lymphoid infiltration consisting of mixed population of lymphocytes, lymphoblasts and reticulo endothelial cells. Polymerase Chain Reaction (PCR) was employed for the isolation and identification of the etiological agent and the results confirmed that four birds out of six, had co-existence of all the three lymphoproliferative disease conditions namely, Marek’s Disease, Avian Leukosis and Reticuloendotheliosis.