The dog is the first domesticated animal, and is symbolically associated with loyalty and vigilance, often acting as guardian and protector. Dogs are portrayed as guides and companions, hence the notion of "man's best friend." Often associated with art and cunning, as it can be trained to do the greatest variety of jobs.
While rarely negative symbols, they do have some unfavorable characteristics. Can be a depraved animal, cursed their enemies. 'Sick as a dog' came from the notion that they return to their vomit. Hated (with a few exceptions) at the end of the Bible: 'dogs, and sorcery, and whor*mongers' outside New Jerusalem. Also a scavenger, envy, flattery, fury, war, greed, pitiless, bragging and folly. Shakespeare often linked them negatively with kites.
