FIGURE 2.

Histopathologic changes of different age ducks infected with DTMUV. (A) 1-week-old ducks, brain, 3 dpi: cerebral vascular endothelial cells swelling; (B) 1-week-old ducks, brain, 5 dpi: typical viral encephalitis; (C) 3-weeks-old ducks, brain, 7 dpi: severe perivascular inflammatory infiltrates; (D) 7-weeks-old ducks, brain, 7 dpi: mild perivascular inflammatory infiltrates; (E) 1-week-old ducks, heart, 3 dpi: degeneration and necrosis of myocardial fibers; (F) 1-week-old ducks, heart, 5 dpi: necrosis and bleeding of myocardial fibers; (G) 3-weeks-old ducks, heart, 5 dpi: granular degeneration and mild lymphocytic infiltration; (H) 7-weeks-old ducks, heart, 5 dpi: degeneration of myocardial fibers; (I) 1-week-old duck, liver, 5 dpi: severe degeneration and necrosis of liver, with infiltrating by heterophilic granulocyte; (J) 3-weeks-old ducks, liver, 5 dpi: degeneration and some inflammatory cells infiltration; (K) 1-week-old ducks, spleen, 5 dpi: lymphocytes of white pulp significant reduction and interstitial bleeding; (L) 3-weeks-old ducks, spleen, 5 dpi: lymphocytes of white pulp reduced; (M) 7-weeks-old ducks, spleen, 5 dpi: heterophilic granulocyte infiltration in white pulp; (N) 1-week-old ducks, lung, 7 dpi: interstitial pneumonia; (O) 1-week-old ducks, ileum, 5 dpi: necrosis of lymphocytes in lymphoid follicle.