Medical, Genetic & Behavioral Risk Factors of Sphynx Cats (ePub)

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program was developed, and the CFA granted provisional status to the Canadian hairless, but this recognition was withdrawn due to the breeds health problems.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 rextype 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.