We are a nation of animal lovers, according to the AVMA's latest U.S. Pet Ownership & Demographics Sourcebook, which finds that more than half of U.S. homes include a pet. However, ownership is down 2.4% compared with data the AVMA collected in 2006. "That is something I was not expecting," says AVMA president Dr. Douglas Aspros. "Pets are important for people's mental, psychological and physical health. It's also bad for pets because there are a lot of animals left in shelters." Vermont is the top dog for pet ownership with 70.8% of households including a pet, while only 21.9% of Washington, D.C., homes include a pet.