Dogs have a sense of time. It's been proven that they know the difference between an hour and five. If conditioned to, they can predict future events, such as regular walk time. Your dog is as smart as a two-year-old! Ever wonder why children around this age seem to have a special bond with the family dog? It could be because they speak the same language, roughly 250 words, and gestures in fact. A study at UCSD claims that your dog can genuinely get jealous when they see you display affection for another creature. The United States has the highest pet dog population in the world. Approximately 75.8 million in fact. The Saluki is the world’s oldest dog breed. They appear in ancient Egyptian tombs dating back to 2100 B.C.