So kam der Mensch auf den Hund - Konrad Lorenz
In this book (written in 1949) Lorenz mixes speculations about the nature of dogs with observations of his own and other dogs, and reflections about the relation between the species and humans. I am certain that some of his speculations would not be accepted nowadays; for one thing, he later had to drop his idea that most dogs are descended from the golden jackal Canis aureus, and the behavioral deductions he drew from this idea would have to be modified if not abandoned. Lorenz doesn't always give evidence for his assertions in quite the way I'd expect of a scientist, but after all it's a popular book. In all, there is a lot in this book that recalls the state of animal behavior research at that time; it's a field that has continued to advance rapidly.

Some of Lorenz's advice for the care and training of dogs is by no means consistent with modern American ideas -- people have now almost entirely turned against the idea of hitting or physically punishing dogs, for example -- but it's all based on a genuine love and a wish to understand the dog's own needs and inclinations, from a point of view of unsentimental, unanthropomorphized sympathy. This, indeed, is what has kept Man Meets Dog in print to this day, I think: some of the chapters, the last two and others, contain lovely reflections on Lorenz's own emotional relationship to his dogs and on the bonds of mutual duty and understanding between humans and their companion species. There is an understated call to moral improvement here.