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. Greyhounds do not have undercoats and thus are less likely to trigger dog allergies in humans (they are sometimes incorrectly referred to as 'hypoallergenic'). The lack of an undercoat, coupled with a general lack of body fat, also makes Greyhounds more susceptible to extreme temperatures (both hot and cold); because of this, they must be housed inside. Some greyhounds are susceptible to corns on their paw pads, a variety of methods are used to treat them.