Why Are More People Allergic to Cats Than Dogs?

January 14, 2015

By Linda Cole

A healthy immune system protects us from diseases. It’s a remarkable network of tissues, cells and organs all working in harmony to protect the body from infections, viruses and other microorganisms. However, sometimes the immune system reacts to something it believes is harmful to the body, overreacting in the way it responds. An estimated 15% of people are allergic to cats, dogs and other animals, but it’s our feline friends that cause more people to sniffle and sneeze than dogs. It’s estimated one in seven children between 6 and 19 years of age are allergic to cats. The reason has nothing to do with their hair though; the instigator is a protein found in cats.

Cat allergies in people are triggered by an overreaction of a super sensitive immune system to a protein (allergen) in cats called FEL d1. Scientists have isolated seven cat allergens that contribute to an allergy, but the FEL d1 protein is the most common reason why people are allergic to felines and it’s because of the size and shape of this specific molecule. It’s found primarily in a cat’s saliva, skin and urine.

The protein is spread on a cat’s fur as she grooms herself and can be deposited on your skin when she licks you. Someone who is super sensitive to cats can develop a rash on their chest, face or neck. When reacting to a perceived threat, the immune system releases a chemical, histamine, which causes congestion, runny nose, sneezing, itching and watery eyes. Symptoms can range from mild irritation or sneezing to life threatening flare ups in asthma sufferers. An allergic reaction to cats can happen immediately or appear four to eight hours after contact with a feline.

It’s possible to develop an allergy to certain foods, dust, mold, pollen or pet dander (particles of dried skin) at any time in your life. Just because you have never been allergic to pets in the past doesn’t mean you will never develop a cat or dog allergy. Cat allergies are twice as common as dog allergies, and people who are allergic to dogs can have a reaction to only some breeds.

People who are allergic to cats can have a reaction to felines regardless of the breed – even hairless breeds – and it is possible for some people to have an allergic reaction when around big cats. All felines produce FEL d1, but some individual cats produce less than others. You may be fine around one cat, but not around others. There are no cat breeds that are hypoallergenic. Male cats, especially ones that haven’t been neutered, produce more of the protein than females do.

It’s not cat hair that causes an allergic reaction, and even though dander can contain the FEL d1 protein, neither the coat nor dander cause someone to be allergic to cats. Allergens are present throughout the home and can remain active for several months. FEL d1 is around a tenth the size of dust allergens and drifts around in the air. It’s extremely light, and these microscopic allergens can float for hours and easily be inhaled into the lungs. Dog allergens don’t float around in the same way or as long as cat protein does. You can have an allergy to cats and not be bothered at all by dogs.

FEL d1 is also extremely sticky and can adhere to your skin, walls, clothing, bedding and other porous surfaces. It’s possible to carry the allergens on your shoes and clothes to places where cats have never been, like your pet-free friend’s home, the doctor’s office, your work place or a restaurant. The protein has even been found in the Arctic. Pet dander can be found in homes on walls, ceilings, fixtures, furniture, carpet, curtains and other places up to two years after a cat is no longer around.

Brushing or combing your cat daily can help reduce the amount of allergens in the air. Weekly baths may help as long as your cat’s skin doesn’t become dry and flaky. Changing your pet’s diet to a premium quality food containing Omega-3 fatty acids can help keep their skin healthy and supple. Shaving a cat will not help an allergy sufferer.

Last year, researchers from the University of Cambridge discovered that when cat dander comes into contact with a bacterial toxin – lipopolysaccharide or LPS – commonly found in the environment, it can trigger an allergic reaction to cats. They were also able to pinpoint which part of the immune system recognizes it: a receptor called TLR4. This research may bring about new treatments for people who deal with cat allergies as well as dog and dust mite allergies.

Top photo by Austin Kirk/Flickr
Bottom photo by A. Davey/Flickr

Read more articles by Linda Cole

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  1. Susan Huff says:

    Thank you for that information, it was very helpful

  2. I Debra Jean Baldwin says:

    I always wondered this, as I have several friends and lived ones that claim a dog allergy, but sleep with cats, and blame my dogs on their sneezing, etc

  3. Allison says:

    i have a cat even though im allergic. I love both cats and dogs

  4. Khanya Makhanya says:

    lm happy l went trough yo article. Myself i hv allergies i try to keep away frm areas or things dt triggers it. Ds is or of a kind of illeness which is complecated coz it can bring about other conditions like asthma, eye problems……..We need to be recognised as well & be offerd free proper help. Im using private doctors lots of tyms

  5. June Compton says:

    If only 15% of the population is allergic to cats, why do 90% of the people I know claim to be allergic to cats?

    1. I wonder this same thing June. Certainly more than one in seven people I know claim “I’m allergic to cats”, and some take it a step further to volunteer “I dislike cats”.

      I usually laugh at those who claim they dislike cats, and retort “interesting, Hitler disliked cats too… aww, that’s too bad you seem to have disdain for them, as a kitty would love you given the chance”. Obviously I dig cats… I love all animals, but think I identify more with cats.

      Lastly, I’ve had two friends who owned cats, who had met their now wives, and gotten rid of their cats as their new lives were both “allergic” to cats. Oddly, both couples are now the proud owners of 2-3 cats each!

      My take, most people who say they’re allergic to cats aren’t too intelligent, prefer an animal that will sit, paw, fetch, et -i.e., do as commanded. People who like cats respect a cat’s independence and “I’ll do what I want, when I want” type behavior. Cats are such lovely creatures, and do love their humans -but they love on their own terms.

      Here in the US it’s dog country… I wish more people gave cats a chance, but it’s their loss. “Allergies”, hah. I know legit cat allergy sufferers, but my take is most who claim “ohh, get the cat away, Im allergic”, dislike how most cats don’t behave as subordinant pets, i.e., like dogs. Dogs rock too, don’t get me wrong… but kitties rock to their own beat.

      1. Marie says:

        You are making a judgment based on opinion not fact. I have asthma and my allergies of which there are many trigger the asthma. Pets are my worst allergen. I have been to two allergy doctors, had the scratch tests twice with the same results. Maybe you should study up on things before you make such sweeping comments.

      2. Nina says:

        Wow, my husband loves animals but is allergic to cats. He grew up with a cat but the family had to give the cat away because the allergy was so severe. I do not mean to brag, but he gruduated from Yale (magna cum laude), Harvard Law (summa cum laude), and London School of Economics. He is a law professor now. I hope you do some research and stop being biased. I don’t think an intellectual person would make such an ignorant and arrogant statement.

      3. Heidi says:

        I find it interesting that in a post where you bemoan the bias against cats, you yourself are showing some intense bias against dogs through some rather passive-aggressive statements about them (yes, you state near the end that you also like dogs, but it comes across more as an appeasement to dog lovers than a genuine unbiased appreciation of all animals). How about a) a lot of people legitimately have cat allergies, and b) people also just have (and are entitled to) personal preferences with pets as with many things?