Histopathological study of spleen infected by Marek’s Disease Virus (MDV) in broiler chicken

Marek’s disease virus (MDV) is highly contagious in chicken farms and is a cell-associated oncogenic herpesvirus. The gross morphology and histopathological characteristics of neoplasm are one of the important components of diagnosis. The spleen of infected birds 6-10 weeks old were obtained from a broiler chickens in poultry estate, Gadap, Karachi district, Sindh. On histopathological examination lymphoreticular infiltrations of neoplastic cells were seen under high magnification. A number of atrophied cells and extensive inflammatory reaction was present. Lymphoid cells of various sizes, lymphoblasts and immature cells were observed. Necrotic foci and haemorrhages were present. In some slides focal pleomorphic cell proliferation was obvious. Besides neoplastic lymphocytic aggregation and dysplastic foci were observed