The mosaic, dating to approximately 70 AD features the latin phrase, "cave canem" meaning "beware of dog."
While current theories of Rome's decline focus on the Empire's political corruption, outsourcing of jobs to barbarians, large trade deficit, and huge military expenses, experts say this new theory could gain popular support.
Although the first responsibilities of dogs in Rome were for companionship, hunting, and protection, it is well documented that Romans began misusing the animals. They were known to pit the animals against each other for entertainment, as well as breeding them for use in battle against foreign enemies. (Romans often used a large, now extinct breed known as "Molossians" in battle- The dogs were the proverbial "Dogs of War" and were similar to large Rottweilers and are the ancestors of the Mastiff.)
Perhaps Roman dogs became disappointed with their owners' selfish priorities, and decided to topple the empire, sending the world into the Dark Ages?
As the leader of the world, perhaps Rome should have used their power and resources in positive ways such as supporting dog rescue and other important domestic issues. In any event, perhaps we could all learn from the Roman's mistakes, and cave canem.