Hairlessness in cats is a naturally occurring genetic mutation, and the Sphynx was developed through selective breeding of these animals, starting in the 1960s.

Per the breed standards, they have a somewhat wedge-shaped head with large eyes and ears, quite long legs and tail, and neat rounded paws.

[4] Two different sets of hairless felines discovered in North America in the 1970s provided the foundation cats for what was shaped into the existing Sphynx breed.

The current American and European Sphynx breed is descended from two lines of natural mutations: The Canadian Sphynx breed was started in 1966 in Toronto, Ontario when a hairless male kitten named Prune was born to a black and white domestic shorthair queen (Elizabeth).

[4] After purchasing these cats in 1966 and initially referring to them as "Moonstones" and "Canadian Hairless", Ridyadh Bawa, a science graduate of the University of Toronto, combined efforts with his mother Yania, a longtime Siamese breeder,[6] and Keese and Rita Tenhoves to develop a breed of cats which was subsequently renamed as Sphynx.

[6] The first noted naturally occurring foundation Sphynx originated as hairless stray barn cats in Wadena, Minnesota, at the farm of Milt and Ethelyn Pearson.

[5] Two hairless female kittens born in 1975 and 1976, Epidermis and Dermis, were sold to Oregon breeder Kim Mueske, and became an important part of the Sphynx breeding program.

However, due to the "hr" mutation, the hair of Sphynx cats lacks a solid root or bulb, making it extremely weak.

Consequently, the hair is fragile and loosely attached, causing it to fall out easily and contributing to the breed's nearly hairless appearance.

[14][further explanation needed] Care should be taken to limit the Sphynx cat's exposure to outdoor sunlight at length, as they can develop sunburn and skin damage similar to that of humans.

In general, Sphynx cats should never be allowed outdoors unattended, as they have limited means to conserve body heat when it is cold.

[18][better source needed] The skin of the Sphynx cat is known for its excessive production of a greasy secretion, which often results in the accumulation of a sticky, dark brown, or reddish-brown layer that necessitates regular cleaning.

Additionally, they often accumulate oils and debris under their nails and within their numerous skin folds due to the lack of fur.

[20] The lack of hair can cause health issues with kittens in the first weeks of life because of susceptibility to respiratory infections.

[25] Congenital myasthenic syndrome (CMS) previously referred to as muscular dystrophy, myopathy or spasticity, is a type of inherited neuromuscular disorder associated with alpha-dystroglycan deficiency, found in Sphynx and in Devon Rex cats as well as variants of these breeds, which can occur between the first 3 to 23 weeks of their life.