Cat Dander: 8 Things You Didn’t Know

By PetMD Editorial on Jun. 22, 2016

By Matt Soniak

We all know that cats (and dogs) are responsible for allergic reactions in some people. And one of the major culprits is dander. But what exactly is cat dander and why does it cause allergies in people? Let’s find out.

1. Dander is made up of the microscopic bits of dead skin that cats (and also dogs, people and really any other animal with feathers or fur) naturally shed.

2. When it comes to allergies, the dander itself isn’t the issue, but two allergens that it can act as a vehicle for. The main allergens associated with cat dander are two proteins called Fel d 1 and Fel d 4. The first is produced both by cats’ skin and their sebaceous glands (which secrete a waxy substance called sebum that helps waterproof and lubricate their skin), while the second is produced in cat saliva and deposited on their skin when they grooms themselves. The dander can trap these allergens, says Dr. Christine Cain, a veterinarian and Assistant Professor of Dermatology at the University of Pennsylvania School of Veterinary Medicine, and spread them around as the hair is shed.

3. These cat allergens are very small, Cain explains, and can potentially make their way all around the home. In fact, they’re among the smallest of the major allergens — a fraction of the size of dust particles. That means they can become airborne easily and spread around before settling on different surfaces. Part of the difficulty with cat dander and cat allergens, Cain says, “is that they’re pretty ubiquitous, so even people who don’t have cats can still have cat allergen in their house.”

4. How do these tiny proteins cause such big problems for some people? An allergy is the result of your immune system mistaking a harmless substance—in this case, the cat’s proteins—for something more dangerous, and reacting the way it would to a pathogen or another invader. The immune system makes antibodies to fight off what it sees as a danger, causing allergy symptoms like itching, a runny nose or an asthma attack.

5. Cat allergies are roughly twice as common as dog allergies, according to the Asthma and Allergy Foundation of America (AAFA). The allergens associated with cat dander are different than those find their way onto dog dander. With dogs, the trouble making proteins are Can f 1 and Can f 2, which are produced by dogs’ salivary glands.

6. The amount of allergens that cats produce doesn’t differ from breed to breed, but does differ among individual cats. Cain says that male cats tend to produce more allergens than females. Among males, neutered cats produce less than intact ones. Research has produced mixed results regarding another factor: fur color. Some research found that dark-colored cats are more allergenic than ones with lighter fur, but other studies suggest that fur color had no link to allergen amount. Another study found that people living in the Western U.S. had higher cat allergen concentrations in the homes than those in other parts of the country.

7. There are a number of ways pet owners can cut down the amount of cat dander and cat allergens in their homes. Bathing can be effective, but requires some commitment. “Sometimes for it to be helpful, you have to bathe your pet pretty frequently, like twice a week,” Cain says. If that seems like too much to ask of yourself or the cat, you can tackle the dander that’s already loose in the house. The AAFA recommends keeping your cat out of the bedroom, removing surfaces like rugs and carpets that allergens can stick to, changing and washing clothes after long exposure to your cat and using an air cleaner with a HEPA filter.

8. While some people think that hairless cats or certain “hypoallergenic” breeds can bring them relief from their cat allergies, that’s not really the case. “There is no true hypoallergenic breed,” Cain says. “That's a complete misnomer.” While hairless cats can be beneficial in that additional allergens like dust or pollen won’t cling to their coats, they still produce the same allergenic proteins as other breeds.

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