Figure 4

Histopathological findings of CAV infection in tissues from 4-week-old SPF chickens. Animals were studied 14 days after infection with CAV or inoculation with PBS at 2 weeks of age, and pictures show representative tissue samples from experimental and control groups stained with HE, 10× (a-f). (a) Thymus lobe from PBS inoculated group; (b) thymus lobe from CAV-10 inoculated group with severe cortical lymphocyte depletion and absence of demarcation between the medulla and cortex; (c) thymus lobe from CAV-18 inoculated group; (d) bursa of Fabricius from the PBS inoculated group; (e) bursa of Fabricius from CAV-10 inoculated group, showing moderate lymphoid depletion of the follicles with follicular atrophy marked with an arrow; (f) bursa of Fabricius from the CAV-18 inoculated group. (g) Large lymphoblasts with karyomegaly in thymuses from CAV-10 inoculated chickens, 40×; vacuolization of reticular cells were also marked by arrows.