Medical, Genetic & Behavioral Risk Factors of Sphynx Cats

About the Book

This cat first appeared as a mutant hairless kitten born in a litter of short-haired cats in 1966 in Ontario, Canada. As he grew older, this original kitten developed a short, downy coat with thin, short hair present on the ears, muzzle, tail, feet, and testicles. A breeding program was developed, and the CFA granted provisional status to the Canadian hairless, but this recognition was withdrawn due to the breed’s health problems. Three additional hairless cats were found in Ontario, and two female cats were sent to Dr. Hugo Hernandez in Holland and crossed with Devon rex cats. In 1975, Milt and Ethelyn Pearson of Minnesota discovered a hairless kitten born to a brown tabby shorthair. When these cats were bred to normal short-haired cats, they produced normal kittens. But when inbred, they produced hairless cats, indicating that the hairless gene is recessive. Hairless cats from the Pearsons were bred to rex cats and were the foundation of the Sphynx breed. The CFA recognized these new versions of the Sphynx in 1998 and granted them championship status in 2002. The breed has become very popular, ranking eight out of forty-three breeds in 2014 CFA registrations. Sphynx may be outcrossed with American shorthairs and domestic shorthairs/domestic Sphynx outcrosses, but all Sphynx born after 2010 must have Sphynx parents. It is also possible to get partially hairless kittens in some lines of the Devon rex and Cornish rex breeding programs, but these cats are not considered Sphynx. Hairlessness is caused by a recessive gene. All normal hair coats are dominant to this gene. The Devon rex gene, however, is recessive to the hairlessness gene of the Sphynx. The mutation for both hairlessness in the Sphynx and the Devon rex coat are located on the Keratin 71 (KRT7!) gene. Due to scarcity of purebred Sphynxes, Devon-Sphynx crosses are necessary to perpetuate the Sphynx breed. A Sphynx with both Sphynx hairlessness genes when crossed with a Devon rex will produce all Sphynx kittens. The offspring will all carry one gene for Devon rex–type haircoat. So some are heterozygous Sphynx (have one Sphynx gene and one Devon gene). Although Devon rexes can be born to heterozygous Sphynx parents, it is important to realize they do not have the Sphynx gene for hairlessness and are genetically Devon rex. The UC Davis Veterinary Genetics Lab offers a DNA test to determine if the Sphynx tested carries the gene for the Devon rex coat.

About the Author

Ross D. Clark, DVM is the founder of Woodland PetCare Centers and a cofounder of National PetCare Centers. He received his doctor of veterinary medicine degree in 1963 from Kansas State University. He is practice management editor for Veterinary Economics Magazine and served as president of the Tulsa County Veterinary Medical Association, the Oklahoma Veterinary Medical Association, and also as president of the Western Veterinary Conference—the world’s largest continuing education conference for veterinarians. American Animal Hospital Association named him Outstanding Practitioner for the Western Region in 1987 and National Merit Award Winner in Toronto, Ontario, Canada, in 1991. Veterinary Partners Incorporated, an organization of veterinarians, lawyers, and accountants that do practice management consulting, recognized Dr. Clark with their prestigious Pioneer Award at the Western Veterinary Conference in 2004. He served two terms as president of Kansas State University Veterinary Medical Alumni Association from 1990 to 1992, and Kansas State University named him an “alumni fellow” in February of 2003. Over the past forty-five years, Dr. Clark and his partners have cared for show dogs from most states in the United States of America, plus show dogs from Canada, Mexico, and Spain. He is the author of eight books, including Medical, Genetic, and Behavioral Aspects of Purebred Cats and the coauthor of the first and second edition of Medical and Genetic Aspects of Purebred Dogs. He is also author of four management books: first, a practice management manual; second, The Best of Ross Clark; third, Mastering the Marketplace—Taking Your Practice to the Top; and his latest book, Open Book Management for Veterinary Hospital Teams. He has toured throughout the world as a practice management lecturer and consultant. In addition, Dr. Clark has been a Veterinary Economics “Hospital of the Year” judge for over twenty-eight years. Dr. Clark is currently owner and managing partner of four small animal practices and three pet resorts in Oklahoma. Dr. Clark and his team have been doing veterinary practice management consultation, seminars, and appraisals since 1981. Ross is married to Linda Clark, and they have two children, twins Kent and Kimberly Clark.