The Greyhound is a breed of dog, a sighthound which has been bred for coursing game and greyhound racing. Since the rise in large-scale adoption of retired racing Greyhounds, the breed has seen a resurgence in popularity as a family pet. It is also referred to as an English Greyhound. While similar in appearance to Saluki or Sloughi, DNA sequencing indicates that the greyhound is more closely related to herding dogs. This suggests that Greyhounds are either progenitors to or descendants of herding types. Historical literature by Arrian on the vertragus, the first recorded sighthound in Europe and possible antecedent of the Greyhound, suggested that its origin lies with the Celts from Eastern Europe or Eurasia.