When your pets are home alone, are you sure they're really there? Really? Put yourself in the position of a beloved pet whose family has just installed a new pet door to the backyard. But instead of the backyard, there's a teeming city populated entirely by pets. The stores, restaurants, and theaters, the public transportation, the museums, parks, and municipal services are run by a huge assortment of well-dressed cats, dogs, rabbits, mice, hamsters,...