I really like this photograph for a number of reasons. I'm not sure if its intentional, but I really like how the ground and the plants in background are brightly colored blues and greens, and how the cat and the mouse are more muted earthy brown and black tones. I also like how focused the mouse is. and how forlorn the dead mouse is. overall, great.
I want to let you know that the low score I gave you on this was not because of the subject matter (although it does not at all appeal to me) but because your execution (uh...pun not intended. LOL) of the shot isn't very interesting. I think it might have come across a bit more artistic had you chosen black and white over color, since the teal of the ground is very uncomplimentary to the green of the foliage behind the cat. I like the DOF fine.
Good shot. Cat in the background see,s none too happy that your playing with its prey:) I love how you haev put the cat directly in the background and in soft focus. I do find however that the frame is a bit much. You're image already says so much. No need to take away from it with an overly ornate frame. I really like this one.