The Truth About Hypoallergenic Pets

It’s unfair that some humans are allergic to humankind’s best friend. An adorable dog or cat ought to bring joy to those around it, not miserable sniffling and sneezing. But between 10 and 20 percent of the world population is allergic to cats and dogs, marking a significant portion of people who are sensitive to two of the world’s most popular household pets.

Hypoallergenic cats and dogs are a purported solution. But what does it mean to be hypoallergenic — and does such a trait really exist?

What does a hypoallergenic pet really mean?

Cats and dogs produce several allergenic proteins, Sandra Koch, a veterinarian and professor of comparative dermatology at the University of Minnesota College of Veterinary Medicine, tells Inverse. The most common ones appear in their saliva and shed skin, or dander. People with allergies to these proteins experience immune reactions, meaning their immune system responds as if they’re bacteria or viruses, deploying a bevy of unpleasant symptoms like sneezing, itching, or coughing.

Some cats and dogs are deemed hypoallergenic, which means they’re “relatively unlikely to cause an allergic reaction, but still can,” Koch says. Dog breeds believed hypoallergenic include hairless terriers, poodles, bichon frise, and schnauzers while cats include the Cornish Rex and hairless sphynx, according to Koch. These animals supposedly don’t shed as much, or might be hairless altogether, but that might not make a difference when it comes to allergies. Koch says that dogs can produce allergens in their blood, prostate, and anal glands, while cats make allergens in their skin oil glands, anal glands, blood, and male cats produce them in urine.

Salivary allergens are especially problematic because as cats and dogs groom themselves, they spread these proteins all over their body. These compounds can also hang around in the air for several days. Even if you get a hairless cat or dog, an allergy to their saliva can make them a menace to your immune system.

What the studies really say about hypoallergenic pets

Research fails to show any big differences in the amount of allergen in the air of a home with a hypoallergenic dog compared to one without one. A 2012 study published in the Journal of Allergy and Clinical Immunology sampled hair from 196 hypoallergenic dogs and 160 non-hypoallergenic dogs, as well as airborne dust samples from the animals’ homes. They searched for major sources of the allergen Can f 1, a common dog allergen, which they detected in “almost all hair and coat samples.” A 2011 paper published in the American Journal of Rhinology & Allergy came to similar conclusions. It also analyzed Can f 1 levels in dust samples from homes with both kinds of dogs. Allergen levels didn’t differ significantly between homes in this case, either.

As for cats, one small study from 2014 published in the journal Clinical and Translational Allergy involved 14 cats. It found that hypoallergenic cats secreted and distributed less of the allergen Fel d 1 compared to non-hypoallergenic cats.

Still, Koch is hesitant to put her confidence in hypoallergenic cats because of allergies’ complexity. “Not all dogs and cats produce or shed the same amount of allergens,” she says.

While hypoallergenic pets may have good marketing, Koch says there is not enough data to make any definitive claims. She says that while some breeds shed less or not at all, “the truth is that all furred pets have the potential to cause a reaction in an allergic individual and, to this date, no breeds have been scientifically proven to be ‘allergy proof.’” You might think that “furred pets” is the catch, meaning hairless pets are safe, but since allergens can come from saliva, blood, and glands, fur isn’t the biggest factor.

So is there such thing as a cat or dog that’s free of allergens? “The simple answer is no,” says Koch. “Allergy is very complex and the allergen triggers and contributing factors can be quite different among individuals.”

Editor’s Note: This story has been updated to reflect the fact that while there is some data investigating the effectiveness of hypoallergenic pets, there is not enough data to make absolute claims.