Figure 10.

Histopathological changes in the bursa of Fabricius of NDV infected chickens. Section of the bursa of Fabricius of control chickens showing age-related mild lymphoid depletion (a). Sections of the bursa of Fabricius of infected chickens showing marked depletion of lymphocytes in the bursal follicle leaving numerous empty spaces at 24 hpi (b), follicular atrophy leaving necrotic masses, hemorrhages and infiltration of inflammatory cells at 4 dpi (c) and massive necrosis resulting in disappearance of lymphoid follicles, moderate hemorrhages and profuse inflammatory cells at 5 dpi (d). H&E stain, bar indicates magnification.