All the Trivia You Could Ever Hope to Find about CATS! Cat Stats... Cats, not dogs are the most common pets in America. There are approximately 66 million cats to 58 million dogs, with Parakeets "flying" a distant third at 14 million. More than one million stray dogs and over 500,000 stray cats live in the New York City metropolitan area. There are more than 100 million dogs and cats in the United States.  Americans spend more than 5.4 billion dollars on their pets each year. The average outdoor-only cat has a lifespan of about three years. Indoor-only cats can live sixteen years and longer. A cat has approximately 60 to 80 million olfactory cells while a human has about 5 to 20 million.