survey conducted by The Kennel Club, cardiac problems were shown to be the second leading cause of mortality in Whippets. A 2007 study identified a myostatin mutation particular to Whippets that is significantly associated with their athletic performance. Whippets with a single copy of this mutation are generally unaffected; those with two copies have disproportionately large musculature and are known as "bully whippets". These bully whippets experience no significant health problems beyond those experienced by a normal whippet, but may be more prone to muscle cramping. The mutation has not been seen in Greyhounds or other sighthound breeds, or in heavily muscled dogs such as Bullmastiffs, Bulldogs, Rottweilers or American Staffordshire Terriers. Whippets in literature Jim the Whippet played a central role in a trilogy of canal travel books by Terry Darlington. Described as a 'narrow dog' he lent his name to the book's titles - Narrow Dog to Carcassonne, Narrow Dog to Indian River and Narrow Dog to Wigan Pier. In popular culture The Whippet is the mascot of Whitewater High School in Whitewater, Wisconsin and Kosciusko High School in Kosciusko, Mississippi. See also Dogs portal List of dog breeds References External links The Origin of the Whippet at justwhippetsrescue.co.uk FCI breeds Dog breeds originating in England Sighthounds