Enlightenment doesn't always come in the form we expect it. It need not be a self-styled guru or a complicated contraption measuring some mysterious quality. Sometimes it's as close as the chocolate lab bounding happily through the backyard, or the feisty terrier contentedly curled up on one's lap for a nap. In the foreword to this thoughtful, wonderfully illustrated gift book, Dr. Bernie Siegel says, "Dogs are healers. . . . They seem to have figured...