Why are Sphynx cats hairless?

Sphynx cats are famous for their lack of fur and distinctive wrinkles. They are the marmite of cats, with most people falling into the ‘love them’ or ‘hate them’ camps.

It’s perhaps not surprising that Sphynx cats are sensitive to the cold and prone to sunburn in the summer, so most are indoor-only cats. They require regular bathing, as oils that would normally disperse along hair shafts will instead accumulate on the skin of hairless breeds.

Contrary to popular opinion, Sphynx cats are not completely hypoallergenic as they still produce skin cells, or dander, as it’s often referred to. However, the lack of hair may be enough to reduce an allergic reaction for allergy sufferers. But why don’t Sphynx cats have hair?

Why are Sphynx cats hairless?

“It’s due to a mutation in the gene that is responsible for providing hairs with their keratin protein as they emerge from the follicle,” said Charlotte Corney, zookeeper and founder of TheWildheartTrust. “The hair is formed, but it has a weaker structure and becomes easily damaged and dislodged.”

Sphynx cats were originally called the Canadian Hairless, as the first recorded appearance came from Toronto in 1966, when a domestic cat gave birth to a hairless kitten, later discovered to be the result of a natural genetic mutation. The cat was aptly named ‘Prune’ and began the first hairless cat breeding program. Although it’s difficult to know whether all modern hairless cats are descended from Prune, or other cats with this genetic mutation.

"This genetic mutation can occur in cats naturally, but selective breeding for this trait since the 1960s has produced the Sphynx breed. Some Sphynx cats are completely bald, while others have short downy fur over their bodies or in isolated areas," said Corney.

Specifically, the recessive mutation is in the keratin 71 gene (KRT71), which plays a key role in hair formation. It’s part of a family of type II keratins that are present in all mammalian epithelial cells - these are cells that line the surfaces of the body, acting as a sort of safety shield. KRT71 encodes a protein that is expressed in the inner root sheath of the hair follicle.

When a gene is 'expressed' in biology, it's essentially 'turned on'. Instructions in the DNA are converted into the structures present and operating in the cell, causing the body to produce proteins in its code. Clever.

Other phenotypes (a set of characteristics or traits of an organism) have been recorded as a result of mutations in KRT71. Previous studies have found that this gene is also responsible for curly/wavy phenotypes in dogs, mice, and rats.

What do Sphynx cats feel like?

Like their furry counterparts, Sphynx cats come in all colours, and their coat has a peach-like, fuzzy down, or chamois-like texture. They may sometimes have a little more hair on the bridge of their nose or ears and may also have a small puff at the tip of their tail. Sphynx cats are often likened to warm, suede-covered hot water bottles!

Read more about cats:

• Why do cats purr?
• The ‘if I fits, I sits’ instinct: Cats will sit in a box even if it’s an illusion
• Best cat gadgets to help them live a life of luxury

Are there any other hairless cats?

Yes. Prior to the Sphynx cat, there was the now-extinct Mexican Hairless, and it’s widely thought that the Aztecs used to keep hairless breeds as far back as 1300.

Today, many of our bald cats are the result of breeding Sphynx cats with other breeds. Here are some of the other hairless cats:

Bambino

The bambino is another hairless cat breed, and the result of a Sphynx crossed with a munchkin. Like the munchkin, the bambino has short legs and large ears, and the name literally translates as ‘baby’ in Italian.

Minskin

Similar to the Bambino above, the Minskin is also a Sphynx crossed with a munchkin, albeit smaller, with a permanent kitten-like appearance. This is thanks to the addition of genes from the Devon Rex and Burmese cats, giving it a small, yet stocky body and short legs. The Minskin hails from Boston in the US, and the first was bred as recently as 1998.

Donskoy

Also known as the Don Sphynx or Russian Hairless, the Donskoy is one of the few hairless cat breeds not related to the Sphynx cat. It was discovered in 1987 and is a completely new breed. Unlike the Sphynx cat, whose hairlessness is caused by a recessive mutation, the Donskoy’s is actually caused by a dominant mutation, meaning it's much more likely to produce hairless descendants. It’s a muscular, intelligent and affectionate breed of hairless cat.

Peterbald

The Peterbald is a Donskoy crossed with an oriental shorthair, taking its name from St Petersburg, where the breed was first developed and gained popularity. The Peterbald’s coat varies from a velvety, fuzzy velour to bald and even ultra-bald, the latter of which has no whiskers or eyebrows, and are ‘sticky’ to the touch.

Ukrainian Levkoy

The Ukrainian Levkoy has inward folding ears and is the result of breeding a Donskoy with a Scottish Fold. This breed of hairless cat exhibits notable sexual dimorphism, with the males growing to be bigger than the females.

Elf

The Elf cat is another new breed of hairless cat, created from breeding a Sphynx with an American curl. It inherits the distinctive curled ears of the American Curl, and the apparent hairlessness from the Sphynx.

Dwelf

If Dobby the house-elf was in cat form, this would be it: the Dwelf. This hairless cat is a mix of three breeds, the Sphynx, Munchkin and American Curl. As a result, they have a long body – a bit like a dachshund.

Asked by: Catherine Murphy, via email

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