IHC staining of B. canis antigens in the lesions of four organs (liver, spleen, testicle, and lymph nodes). A, positive staining in the cytoplasm of macrophages, neutrophils and Kupffer cells of the liver (200×); B, Brucella antigens were detected in the cytoplasm of macrophages in the red splenic pulp (200×); C, B. canis antigens in the cytoplasm of interstitial macrophages and spermatogenic cells of the testicle (200×); D, positive staining in macrophages of the lymph nodes (200×).