The Whippet shows the characteristic long legs, deep chest, and narrow waist of a sight hound.

Sight hounds are hounds that primarily hunt by sight instead of by scent. These dogs specialize in following prey by keeping it in sight. The dog must be able to quickly detect motion, so these hounds usually have extremely good vision and smaller ear flaps so as not to obstruct possible sounds. Because the prey is often quite fast and agile, such as deer, the dog must be able to keep up with it. As a result, most of these dogs have long legs for a long stride, a deep chest to support a strong cardiovascular system for long sprints, and a thin, wiry body to keep its weight at a minimum. The fastest sight hounds can reach speeds of over 40 mph (60 km/h).

Sight hounds similar to the Saluki have existed for at least 5,000 years, with the earliest known sighthounds appearing in Arabia. Although today sight hounds are kept primarily as pets, they have been bred for thousands of years to detect movement, chase, capture, and kill prey. They thrive on physical activity. Most have mellow personalities, but the instinct to chase running animals remains strong.

This family includes