John:
   Bunny rabbits do it too, but of course they are not eating meat so
their dodo (snicker) is not near as disgusting.  In some ways it is like
a cow or deer and their cud.  As for dogs, I don't think it is the
same.  Bless their little hearts, dogs are just disgusting.  They are
also territorial and I would guess that since urine and feces are used
to mark boundaries they are just trying to change the borders (or owners
thereof).  I have always been _real_ glad that we don't sniff butts like
other animals.
Bev