Vol. 11, Special Issue 7 (2022)

Author(s):
N Akhila, V Samatha, V Rama Devi, Ch Sudha Rani Chowdary, Y Yashaswi and V Padmini

Abstract:
The objective of this study was to identify the visceral type of Marek’s Disease in unvaccinated desi birds. A total of eight dead birds of age 13–15 weeks from a desi poultry flock were presented for necropsy to the Department of Veterinary Pathology, NTR CVSc, Gannavaram. The visceral form of MD was diagnosed by gross, cytological and histological examinations. On external examination the birds were emaciated, dehydrated, with pale and anaemic combs and wattles. Grossly, visceral organs (liver, spleen, kidneys, testes, heart, lungs and proventriculus) were enlarged with presence of focal to diffuse nodular growths. Cytological examination of impression smears collected from heart, liver, and spleen during necropsy revealed a mixed population of pleomorphic lymphoid cells. Histopathology of these affected organs revealed diffuse infiltration of pleomorphic lymphoblasts, small and medium-sized lymphocytes, a few plasma cells, and macrophages. Molecular diagnosis of MD was performed by polymerase chain reaction (PCR) amplification of the vv pathotype of Marek's Disease Virus in suspected birds by targeting 434bp fragment of the LTR region.