You will notice a hard shadows cast by the dog and a dark horizontal area, which is caused by the screen lighting conditions. Decrease the value of Background Shadows Select until all unwanted shadows have vanished, but the hard shadow of the dog is still visible. Increase the value of Darken to enhance the selected shadows . The enhanced shadow will be grainy, so it is good to check Smooth . You should use Field processing to avoid mixing the two fields in the shadows smoothing pass.
Reflections Switch to the Full Composite view.
Depending on the chroma color you have selected there may still be more or less spill on the dog. You can also use the Tune Reflections picker to suppress spill. You can check the areas influenced by reflections in the reflections tool view. Watch the reflections with different backgrounds or by color correcting the background towards different colors. Generating a matte out You may use Zbig V2.0 to generate a matte output instead of the final composite.