"What is "Kemono" art and what differentiates it from "western art""?
This is very much a matter of opinion, however on this board it will be as follows:
Originally it referred to Japanese art and media centralising anthropomorphic animal characters, the word itself is a contraction of the Japanese word for "Beastman". However since then, the term has grown to accept many art styles of Anthro-centric art that are common mostly in east/south-east Asia (Japan, China, Thailand, etc), though it is not limited to artists from that region, some artists from N.A. and Europe emulate the style as well. For the purposes of this site, Kemono is a blanket of styles, not a nationality.
An example is the pic used in this post, though the artist is Chinese, many would consider much of his art to be "kemono" art.
If you're still confused, just lurk the board and you'll pick it up pretty quickly.