There’s No Such Thing as a Hypoallergenic Cat

The newspaper ad promised hypoallergenic kittens. A longtime cat allergy sufferer, I was all too familiar with itchy eyes that would swell shut and the need to keep Benadryl in my purse for allergy attacks at cat-owning friends’ houses. So the advertisement for Cornish Rex kittens, a rare breed I’d never heard of, sparked my curiosity. With my husband and I working full-time, a cat—a hypoallergenic cat—would be the perfect addition to our household.

By the time I realized that we’d been duped—and I was still very allergic to our new and unusual looking cat—it was too late. The papers had been signed, the kitten was ours, and, to be honest, we were already enamored with his curly short fur and penchant for sitting on our shoulders.

At first I relied on Benadryl and other over-the-counter medications to tamp down my usual allergy symptoms: runny nose, itchy eyes, sneezing. But as the months passed, something strange happened: my allergies began to dissipate. Nearly 16 years later, I find myself telling others that the Cornish Rex is the cat to get if you have cat allergies. A miracle!

Well, not quite. Recently, cat geneticist Leslie Lyons, who runs the University of Missouri’s Feline and Comparative Genetics Laboratory, set me straight: there’s no such thing as a hypoallergenic cat. “You’re not allergic to the hair; you’re allergic to proteins that are in their saliva,” says Lyons, who is a professor of comparative medicine in her university's College of Veterinary Medicine. And every cat, it turns out, has saliva.

Okay, so the Cornish Rex may not be hypoallergenic. But its reputation gives an insight into our deep-rooted obsession with non-allergenic pets—and why we should be wary of it.

A Brief History of the Cornish Rex

While the (arguable) domestication of cats occurred nearly 10,000 years ago, “fancy breeds” like the Cornish Rex were only developed within the past century. The first Cornish Rex was born into a litter of British Shorthairs in Cornwall, England, in 1950. The breeder, Nina Ennismore, noticed that the kitten, which she dubbed Kallibunker, was very different from its littermates. Instead of the stocky, dense body typical of a British Shorthair, Kallibunker’s body was thin and delicate, with an egg-shaped head, bat-like ears, unusually long legs, and curly short hair.

After consulting a geneticist, Ennismore realized that the kitten’s unusual appearance was the result of a spontaneous gene mutation. To preserve it, she bred Kallibunker with his mother (that may sound weird, but it’s more common than you think in animal breeding). Two more kittens were born with the same distinct appearance and a new breed was created. Ennismore, who also bred curly-haired Rex rabbits, dubbed the new breed Cornish Rex after her rabbits and the kitten’s place of origin.

Because of its slim appearance and energetic personality, the Cornish Rex is often called the “greyhound of the cat fancy.” To keep the breed line pure, breeders can only breed a male and a female with the same wavy hair. This is because the “spontaneous genetic mutation that causes the thin hair coat and whiskers to grow in pattern waves instead of straight” is a recessive gene, write feline experts Benjamin and Lynette Hart in their book on cat breeds, Your Ideal Cat.

While inbreeding can be tricky, breeders say it’s essential when dealing with the specific gene responsible for the Cornish Rex breed. And while some species or breeds may experience health-related problems due to excessive inbreeding, Lyons says, “there are a lot of cat breeds that have a small population size that do quite well from a diversity point of view.”

The Cornish Rex falls into that category. “The Cornish Rex mutation is recessive, so you have to always breed a Rex cat to a Rex cat to keep all your cats Rexes,” she goes on. “Cornish Rex seems to be one of the breeds that have lucked out and is rather healthy, probably because the breed started out with a good base gene pool. It doesn't have a whole list of genetic problems associated with it.”

Out of all the cat fancy breeds, Persian cats, whose appearance has changed vastly over the years, make up the majority of this category. According to Lyons, their faces have shortened, which is likely due to the breeding standards of that cat. Cornish Rexes, on the other hand, make up only a small percentage with only a few hundred of them registered every year. And by contrast, their appearance has stayed very consistent since the days of Kallibunker.

The Myth of the Hypoallergenic Cat

Despite the similarities between both the Devon Rex and the Selkirk Rex, the Cornish Rex’s signature curl is unique to the breed. This curl is also referred to as the Marcel Wave, a nod to a popular wavy hairstyle of the 1930s. This unusual short topcoat is where the rumored hypoallergenic claim began. Many people believe that the amount of fur or hair that an animal has is what causes their allergy.

However, as Lyons points out, this isn’t true. Cats are unique within the animal world because they produce a specific protein that other animals do not—even dogs—which is why some people are incredibly allergic to cats and not other species. This is known as the Fel d 1 protein, and it's found in the cat’s skin, saliva and urine.

When a cat licks its fur to clean itself, the Fel d 1-containing saliva dries and becomes an airborne allergen. “When people say dander, what they mean are the proteins that are in the cat's saliva,” says Lyons. “When you're allergic to animals, you're allergic to several different proteins, but the cats have their own special one.” Thanks to that protein, cat allergies are twice as common as dog allergies.

If a cat has more fur, it isn’t that they're producing more allergens—it's that they're putting more allergens into the environment (which is why even bringing a cat into a home for a short time can bother allergic visitors long after the cat is gone). “The hair is a vector for the allergen to get around the house and get into the air,” says Lyons.

While dog allergies also stem from proteins in their saliva, Dr. William H. Miller, a professor of dermatology at Cornell University's College of Veterinary Medicine, points out that cats spread their allergens in a few different ways. “With cat allergens on the skin, they are then on the hands of the cat’s owner, who will take these allergens with her,” says Dr. Miller. “As the cat grooms it covers itself in its saliva which will become aerosolized (turned into vapor) when dry. That, coupled with the cat’s habit of covering every square inch of the house, makes cat allergen very widespread.”

So do any cats truly deserve the title of being hypoallergenic? Nope, says Lyons. “If anything is closest to being hypoallergenic, it’s the Siberian, which is a big long fluffy haired breed,” she says. “People have noticed that specific Siberian cats do not elicit as much of an allergy response as other cats.”

The difference could be that the Siberian has different levels of that Fel d 1 protein than other cats. However, that could also be true of other breeds. A 2017 study found multiple mutations in a small sampling of the Siberian’s genes that encode for the allergen, leading researchers to suggest that these mutations “may play a key role in the allergenic properties of the Fel d 1 protein.” However, further research is needed.

When I ask Lyons how pet owners can best decide which type of cat elicits more of an allergic response than others, she laughs. “The thing is, who’s going to go through a whole shelter worth of cats and sniff each one of them on a different day to see if they have an allergic response?” she says. All I can say is that, while my cat may not be truly hypoallergenic, I’m grateful that other than the occasional allergy flare-up, I’m able to enjoy his company and my health too.

Kristen A. Schmitt | | READ MORE

Kristen A. Schmitt writes about wildlife, sustainable agriculture, environmental issues and the outdoors. Her work has appeared in National Geographic, Fast Company, Audubon, Eating Well, USA Today, Hunt & Fish and others.