In late 1997 I read an amazing book titled "Why Do Cats Paint?"
dedicated to unraveling the mysteries of feline art.  The
masterpieces in question, all beautifully photographed, range from
acrylic paint smeared over outdoor fences to colored refrigerator
magnets in the shape of letters to tangles of twine and dead mice.
For the featured artists some personal background is included, with
discussions of how their kittenhood traumas relate to their style and
a couple tragic tales of cats dying for their art.  Frequently the
artist is shown sitting next to its creation.

Like all art critics, the writers of this book tend to get distracted
from questions of beauty and the artist's intentions and bogged down
in the details of the disputes between different schools of feline
art.  A number of outside critics (curators of museums of non-human
art, experts specializing in feline art, etc.: all the usual suspects)
are brought in to shed some shadow on these subjects.

The authors do, as the title promises, manage to explore the question
of why cats paint to some extent.  Cats use urine and feces in various
rituals involving territorial markings, feline hygiene, etc.
Some acrylic paints apparently smell similar enough to stimulate
analogous behaviors in particularly artistic cats, which can sublimate
those inner drives in order to produce art.  The authors do not
explain why the artistic impulse is so rare in felines compared to
humans.

Rumor has it the authors are dog lovers :-)