"Cultural depictions of dogs extend as far back as 4500 BC when dogs were portrayed on the walls of caves. Representations of dogs in art became more elaborate as individual breeds evolved and the relationships between human and canine developed. Hunting scenes were popular in the Middle Ages and the Renaissance. Dogs were depicted to symbolize guidance, protection, loyalty, fidelity, faithfulness, watchfulness and love. As dogs became more domesticated, they were shown as companion animals, often painted sitting on a lady's lap. Dog portraits become increasingly popular in the 18th century and the establishment of The Kennel Club in the UK in 1873 and the American Kennel Club in 1884 introduced breed standards or 'word pictures', which further encouraged the popularity of dog portraiture." [http://en.wikipedia.org/wiki/Cultural_depictions_of_dogs]