Tissue sections H and E stained of chicken groups challenged with virulent IBDV showing:

A: Bursal depletion of lymphoid follicles and hypertrophy of mucous membrane wit inter follicular edema H and E x 100. B: Bursa: sever depletion of the lymphoid follicle accompanied with inter follicular edema and fibrosis H and E x100. C: Bursa: sever depletion of lymphoid follicle H and E x 200. D: Liver: hydropic degeneration of the hepatocytes cytoplasm H and E x 200.