Gone to the dogs. Why dogs?

In some cultures in the world, animals are praised, adored, almost regarded as human and in some (almost) worshiped. While this demonstrates the close ties and mutually beneficial relationship between man and animals, man also coined a saying that seems to suggest a demeaning of the animal - at least one specie which ironically, on the other hand, is also described as "man's best friend".

The saying "gone to the dogs" is used to describe something or a situation that has gone bad or lost all good things associated with it. The question is, why the dogs when it is known that in many cultures, dogs are very important members of the family and community for various reasons: company, hunting, security, recreation (sports), disaster prediction, etc?

Which culture coined this saying and why? Join me in searching for the answer. As we search, I think we (humans) should also stop 'messing up things' and quickly (as if to avoid responsibility) say they have 'gone to the dogs' instead of admitting that 'we have, in our normal minds, deliberately chosen to mess the things up so badly that they are not even useful to us anymore'. Why don't we 'take these things to the angels' instead? Let us strive to make things better.