The Longhaired Whippet is a medium-sized sighthound. It is a coated variety of the Whippet carrying the gene modification for longer coat. Although controversy originally focused on the origin of the longer hair the modified FGF5 gene for longer hair in Greyhounds and Whippets has been scientifically proven as reported by the College of Veterinary Medicine Michigan State University 2215 Biomedical Physical Sciences.