The Answer:

As of 2011, there were more dog owners (46.3 million households) than cat owners (38.9 million households), but more pet cats (86.4 million) than pet dogs (78.2 million). That's because cat owners tend to have more cats than dog owners have dogs. For the full set of statistics, see Household Pet Ownership.

Check out this recent Infoplease Spotlight to learn what the country's Most Popular Pet Names are.

—The Editors