Sampling sites A-G are shown in Figure 1. Si: Staphylococcus intermedius; Se: Staphylococcus epidermidis (the inoculated strain). NG: no growth; ND: not done. Gross signs of infection were noted as present (+) or absent (-) at necropsy. The shunts of dogs 1, 3, 4 & 5 (bold type) were inoculated with S epidermidis, and dogs 2,6 & 7 remained uninoculated.