All About Allergies to Cats and Dogs

In one of the cruelest twists of fate in this cold, harsh world, some people are born with (or eventually develop) allergies to dogs and cats. A life without puppy and kitten cuddles—is it even a life worth living at all? Here's everything you need to know about how pet allergies work, from the causes to the symptoms and treatments to what your options are if you suffer from pet allergies and also from puppy and/or kitten fever (aka the desperate need to own a dog or cat of your very own).

Young housewife suffering from a cat fur allergy
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What does it mean to be allergic to dogs or cats?

Let's start with the most basic of basics: What exactly does it mean to be allergic to a dog or cat?

Well, here's the good news: If you suffer from a pet allergy, it doesn't mean that your body is just averse to the adorable, innocent perfection that exists only in animals. What your body is averse to are the proteins found in certain animals' skin cells, saliva, or urine (other sources of these proteins include skin oil, sweat, and feces). This means that any contact with (or, in severe cases, even tangential exposure to) air full of cat hair, the slobbery love of puppy kisses, or, well any kind of contact with animal urine can be bad news for someone with pet allergies.

Since most people, even the ones who love dogs and cats the most, don't make a habit of rolling around in their pet's urine, most allergic reactions among pet allergy sufferers are triggered by exposure to the dead flakes of skin (aka dander) that pets shed. No amount of vacuuming or brushing will help keep your pet from shedding dander; any animal with fur has it.

As for how allergies work in the body, it's a function of your body mistaking the allergen in question for a dangerous invader and a risk to the body. Given that interpretation, the body does what it always does when it detects a threat: It attacks. In its attempts to protect the body from this dangerous foe (in this case, the dander from Fido or Mittens), the immune system produces antibodies called immunoglobulin E (IgE), which, in turn, cause certain cells to release chemicals (including histamine—thus the need for anti-histamines when allergies attack) into the bloodstream to target the oh-so-threatening puppy or kitten dander.

What causes pet allergies?

Next up, let's talk about the cause of pet allergies. If you're thinking, "Duh—it's pets. It's right there in the name," then know that we're zooming out one step further to look into what causes a person to develop pet allergies in the first place. Are you born allergic to animals? Do you become allergic as you get older—and if so, why and are there ways to avoid that tragic fate?

Woman With Nosebleed
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The answer is, as you might have guessed/feared, not clear cut. For some people, genetics are to blame and allergies are inherited from our parents—at least to a degree. While having parents who suffer from allergies does seem to make a person more at risk for developing allergies themselves, there doesn't seem to be evidence suggesting that the specific allergy will be passed down. In other words, if your parents have allergies, you are more likely to have allergies in general, but if your mom is allergic to peanuts, that doesn't mean you're going to inherit that specific allergy. You might end up allergic to bees or pollen or cats.

That might cover the issue of kids who are allergic to pets, but what about people who don't develop animal (or other) allergies until adulthood? Experts have a few theories. First, sometimes what seems like the sudden onset of an allergy might really just be the sudden exposure to the allergen. If you've never been around cats much and then you adopt one only to immediately start sneezing and breaking out in hives, for example, you might assume that you've suddenly developed a new allergy when, in reality, your previous limited exposure to cats just wasn't enough to trigger an allergy you've had all along.

Another theory some scientists have suggested is known as the "hygiene hypothesis." Basically, the idea is that we grow up in such unnaturally clean environments in modern Western society that our immune systems simply overreact to harmless things like pet dander. In other words, our immune systems are just too sheltered and they don't know what they should actually be afraid of, so they err on the side of caution and treat puppy saliva like snake venom—you know, just to be safe. In case it was, like, acid puppy saliva or something. This theory is still just that—scientists will have to research the cause of allergies a lot more to get to the root of things definitively.

Man Lying on Bed Petting Cat and Sneezing
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If you have a kid (or plan to in the future) and want to reduce their risk of developing pet allergies during their lifetime, you should make sure to expose them to pets when they're very young—like when they're infants. Some studies have found that if a child lives with a dog during infancy are less likely to develop allergies and less prone to upper respiratory infections than kids who don't have a dog until after their first birthday.

How common are pet allergies?

If you do suffer from pet allergies, you're not alone—not by a long shot. At least 11 million people are allergic to cats alone and roughly 15 percent of people are allergic to some kind of animal. Another stat suggests that as many as three out of every 10 people with allergies in the U.S. are allergic to cats and dogs, to at least some degree. So, the short answer is very—pet allergies are very common.

What are the symptoms of pet allergies?

Like all allergic reactions, the severity of pet allergy symptoms can vary greatly from person to person. Oftentimes, the symptoms will be similar to those of hay fever, according to the Mayo Clinic. Common pet allergy symptoms include sneezing, runny nose, and asthma or respiratory issues, like wheezing, coughing, and difficulty breathing.

Young lady taking care of a cat developing a fur allergy
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Below is a full list of the symptoms the Mayo Clinic lists for pet allergies:

Signs and symptoms caused by inflammation of nasal passages include:

  • Sneezing
  • Runny nose
  • Itchy, red or watery eyes
  • Nasal congestion
  • Itchy nose, roof of mouth or throat
  • Postnasal drip
  • Cough
  • Facial pressure and pain
  • Frequent awakening
  • Swollen, blue-colored skin under your eyes
  • In a child, frequent upward rubbing of the nose

If your pet allergy contributes to asthma, symptoms may also include:

  • Difficulty breathing
  • Chest tightness or pain
  • Audible whistling or wheezing sound when exhaling
  • Trouble sleeping caused by shortness of breath, coughing or wheezin

How are pet allergies diagnosed?

If you suffer from pet allergies, you'll probably know pretty quickly (the fact that you have allergy symptoms every time you're around the pet in question will be a big clue), but getting a formal diagnosis is a little more involved. Doctors diagnose pet allergies using a variety of methods, from the extremely commonsense (like suggesting that you spend time not living with your pet and track if that makes the symptoms go away) to the legitimately medical (like blood and skin tests).

How do you treat pet allergies?

Treating pet allergies will, inevitably, start with a suggestion that you distance yourself from the source of the allergy. For pet-less people, that might just mean avoiding contact with cats and dogs in general, but for pet owners, it could mean making a difficult decision between your personal comfort and health (if the allergy isn't life-threatening, of course) and your relationship with your furbaby.

There are several treatment options available for times when you just can't avoid contact with your adorable allergen. These include medications like antihistamines (over-the-counter meds like Benadryl, Claritin, Allegra, and Clarinex), nasal corticosteroids (like Flonase and Nasonex), decongestants, and even allergy shots in extreme cases.

Do hypoallergenic pets really exist?

If you find that you have pet allergies, you may immediately start Googling for hypoallergenic breeds of cats and dogs—pets that aren't allergen carriers. While there are no known hypoallergenic cat breeds, several dog breeds are commonly thought to be hypoallergenic, including poodles, Portuguese water dogs, several types of terriers, and a number of other dogs. Unfortunately, there's no such thing as a truly hypoallergenic breed. A 2011 study found that the allergen levels among homes of hypoallergenic and non-hypoallergenic breeds were roughly the same. So-called hypoallergenic breeds often shed less than other breeds, which may mean that they don't spread their dander as quickly or as easily and could contribute to the perception that they're allergen-free.

Can you have a dog or cat if you have pet allergies?

Here's the good news: As long as your allergies are relatively mild, you can absolutely still be a pet owner if you have pet allergies.

Experts recommend keeping your bedroom pet-free (so you're not breathing in clouds of dander as you sleep or waking up with the thing you're allergic to sleeping on your face). They also suggest investing in a HEPA filter, which removes tiny airborne pollutants, and creating (and sticking to) a regular and thorough cleaning schedule to minimize the collection of dander in carpets and on furniture.