The writer of an article (that Snopes quoted) claimed it's fake. The author of the book specifically denied it. Not saying it isn't fake (I read Snopes daily--don't know how I never saw that one!), but the lack of research by Barbara & David is a little distressing. They seem to be willing to call out something based on a single Cleveland newspaper article.
Close examination of the photographs (in the book, not on the web) make the claim of fake either more incredible or impressive. We're talking pixel-by-pixel manipulation here, certainly hundreds--if not thousands--of hours for most of these images. Either that, or the felines themselves are CG, and that I doubt.
In any case, thanks for bringing that to my attention. It reminded me of a very good book, regardless of the "truthfulness" of it.