The main commandment of dog life and the foundation of dog morality, I suspect, is something like Know Your Place. Dogs live in hierarchies, and everyone agrees (everyone human) that dogs are happiest when the ranking is clear. The second rule is My Food Is Not Your Food. Depending on the pack and how hungry a dog is, the big dog can turn this on its head, so that rule for the submissive animal becomes My Food Is Your Food - Unless I Eat It First. No wonder dogs have no table manners.
I like this little bit of commentary on human morality though:
Of course, dog morality is to human morality as chimpanzee language is to human language. Humans are able to summon up moral outrage about almost anything, even if it's none of their business. Humans are geniuses at morality and moral outrage. There are so many things we can do wrong, it boggles the mind. And the rules depend on which humans you are with: dancing or no dancing, monogamy or polygamy, card playing or no card playing, sex or celibacy, gay marriage or no gay marriage.
In fact, if moral values and moral outrage are results of evolution, in human beings they may have reached the level of being counterproductive, like the vast antlers that supposedly doomed the Irish elk.