The Chihuahua is the world’s smallest dog and is named for a Mexican state.

The Chihuahua, the smallest recognized dog breed, is named for the Mexican state of Chihuahua, where it was first noted in the mid-19th century. The Chihuahua is thought to have been derived from the Techichi, a small, mute dog kept by the Toltec people of Mexico as long ago as the 9th century AD. Typically a saucy-looking, alert dog that is sturdier than its small build would suggest, the Chihuahua stands about 5 inches (13 cm) and weighs 1 to 6 pounds (0.5 to 3 kg). It has a rounded head, large, erect ears, prominent eyes, and a compact body.