I've spent countless hours considering Marmaduke. Having spent some of those hours spelunking through the strip's archives, I realized that with very few tweaks, it's relatively easy to bring the inherent pathos of the strip to the surface. For most of the following, all I did was change the wording of the caption, though every once in awhile, I added a little bit of blood to sell a gag or rewrote one of Marmaduke's signs to suit my own aims (though, to be clear, not to suit my actual beliefs).
For the record, I actually love Marmaduke, and don't intend to cause offense by my meddling here. Click on any of these to view them in lightbox.