Mammary glands, mammary gland lymph ncdesm medial thcac lyrnaph ncdes, uteri, and placenta of 79 serologically &wella-psitive cat had been crIktl for histc’pathologdal studies from 1979 t’ 1980. Of which, the mammary lymph nedes (58,2%) and the medial iliac lymph ncdes @9.4%) were found with lesions of reticulcendothelial cells ohfexation and accumulation of macrophages in lymphatic sinus, but only 5.1% of serologically lnella-pcxitive cattle showed gianulomatous mastitis. Fifn stray serologically hnuella-negtve dogs were mtravenously incculatd with baella canis and sacsifiecl from one day po€t-inoculation (DPI) 120 DPI in variable intervals. Hyerplasia of reticulcendothelial cells of lymph ncdes and spleens were only detettei initially in the dog killed at 67 DPI, but were not found before 36 DPI. The dogs at 120 DPI showed the most severe lesions in comparison with others.