Fig. 4

Characteristic histopathological lesions in subdermis and synovial joint capsules of treated and non-treated animals challenged with Bb. Non-affected skin-subdermis and synovial capsule are depicted in panels (a) and (c) respectively. Panel b shows a section of subdermis with minimal inflammation in the perivascular and perineural tissue (pointed by the solid arrow). Note the absence of this infiltrate in (a). Panels d to f show inflammatory changes observed in joint capsule from three different dogs. The solid arrows point at areas with mononuclear inflammation. Note the nodular appearance of the inflammation composed mainly by lymphocytes and plasma cells in panel (e). The dashed arrows point at the synovial layer, which is composed by a single-cell layer in the tissue in panel (c). Note the absence of inflammatory infiltrate in this tissue. All pictures were taken at a 400 x total magnification