The Chihuahua is widely recognized as the smallest breed of dog in the world. They typically weigh between 2 and 6 pounds (0.9 to 2.7 kilograms) and stand about 6 to 9 inches (15 to 23 centimeters) tall at the shoulder. Chihuahuas have a compact body structure with a rounded head, prominent eyes, and large ears. Despite their small size, they are known for their spirited and feisty personalities. Chihuahuas come in various coat types, including smooth, long-haired, and even hairless varieties. They are popular companion dogs due to their small size and portable nature.