4 minute read

Furever friends: Understanding cat & dog allergies

Published April 6, 2024

Cats and dogs fill millions of American homes with their love and companionship.¹ They add joy, comfort, and loyalty to our daily lives. But for some (up to 20% of people worldwide), these furry friends can also trigger allergies.¹

What are symptoms of a cat or dog allergy?

Do you sneeze or get itchy eyes around dogs or cats? These could be signs of an allergy. Below are common symptoms to watch out for¹:

  • Sneezing
  • Stuffy or runny nose
  • Itchy nose, ears, or mouth
  • Itchy, watery eyes (might be red, puffy, or swollen)
  • Headache
  • Feeling tired (fatigue)
  • Skin rash, welts, hives, or eczema
  • Wheezing or slight trouble breathing
  • Increased asthma symptoms

What triggers dog or cat allergies?

Fur might seem like the issue, but it’s a collector of the real culprits: proteins found in pet dander (flakes of dead skin), saliva, and urine. It’s the exposure to these proteins that can trigger allergic reactions in people with dog or cat allergies.³

Why are some people allergic to pets like dogs or cats, but others aren't?

It comes down to a misunderstanding by the immune system. The immune system normally protects the body from threats like bacteria and viruses. But with dog or cat allergies, it wrongly identifies harmless proteins in their dander, saliva, or urine as dangerous. This mix-up triggers an immune response, causing the body to produce IgE antibodies against these proteins.³

IgE antibodies are usually found in small amounts in the blood, but high levels can mean the body is overreacting to something. This overreaction causes irritation (inflammation) and leads to allergy symptoms like sneezing, wheezing, or a runny nose. Over time, regular exposure to an allergen can even cause long-term (chronic) inflammation.³

What proteins might trigger dog allergies? How are they tested?

If you think you might be allergic to dogs, the Quest Dog Allergy Test with Reflex to Components checks your blood sample for an immune system reaction (IgE antibody) to a dog dander protein. If this test is positive, the lab will run other tests (called reflex testing) on your sample at no extra cost.

Reflex testing checks for IgE antibody reactions to:

  • Proteins in dog saliva (Can f 1, Can f 2, Can f 4)
  • A protein in male dog urine (Can f 5)
  • Other dog-related proteins (Can f 3, Can f 6). These proteins can provide clues that other animals, not just dogs, could be causing allergy symptoms.

Wait, male dog urine? What about female dog urine?

The test can help uncover if you’re allergic to a protein (Can f 5) found only in male dogs. This means if you’re only allergic to Can f 5, you might have lesser allergic reactions to a female dog.⁴ ⁻ ⁶

What about cat proteins (allergens) and testing? 

If you think you might be allergic to cats, the Quest Cat Allergy Test with Reflex to Components checks your blood sample for IgE antibodies to a cat dander protein. If this test is positive, the lab will run reflex testing on your sample at no extra cost.

Reflex testing checks for IgE antibody reactions to:

  • Proteins in cat saliva and skin (Fel d 1)
  • Other cat-related proteins (Fel d 2, Fel d 4, Fel d 7). These proteins might also explain allergies to other animals, not just cats.

Does a positive test result mean I have a dog or cat allergy?

Tests results can be a helpful first step, but they’re not the final answer. To get a clear diagnosis, it's important to follow-up with your healthcare provider. Only a healthcare provider can diagnose or rule out an allergy and help determine next steps.

Is it true that switching my cat's food might help my allergy symptoms?

Yes. All cats produce Fel d 1, a common allergen found in their saliva. Certain cat foods on the market are designed to neutralize Fel d 1. These specialized diets can help reduce this allergen by an average of 47% by the 3rd week of feeding. So, by adjusting your cat's diet, you can reduce your exposure to allergens, snuggle up with your feline friend, and breathe easier.⁴

Are there hypoallergenic dogs or cats?

While any dog or cat can trigger allergy symptoms, some people find they react less to certain breeds. The key thing to remember is a completely "allergy-free" cat or dog doesn’t exist.¹ 

Dog or cat allergies come from an overreaction to proteins found in the animal's dander, urine, or saliva. Since each part contains different proteins, your reaction might vary depending on the source. But there’s good news: scientists are looking into ways to change these proteins, so they don't trigger allergy symptoms. This could mean a future with fewer allergy symptoms and more cuddles.¹

No doctor visit is required to buy your own lab test at questhealth.com. PWNHealth and its affiliates review your purchase to ensure it is medically appropriate before submitting the test order for processing. PWNHealth also reviews your test results and will contact you directly if they require prompt attention. Included in each purchase is the option to discuss your test results with an independent physician; however, you are also encouraged to speak with your primary healthcare provider.


  1. Asthma and Allergy Foundation of America (AAFA). Pet allergy. Accessed April 1, 2024. https://aafa.org/allergies/types-of-allergies/pet-dog-cat-allergies
  2. Cleveland Clinic. Anaphylaxis. Accessed April 1, 2024. https://my.clevelandclinic.org/health/diseases/8619-anaphylaxis
  3. Mayo Clinic. Pet allergy. Accessed April 1, 2024. https://www.mayoclinic.org/diseases-conditions/pet-allergy/symptoms-causes/syc-20352192
  4. Dramburg S, Hilger C, Santos AF, et al. EAACI Molecular Allergology User’s Guide 2.0. Pediatr Allergy Immunol. 2023;34 Suppl 28:e13854. doi:10.1111/pai.13854
  5. Dávila I, Domínguez-Ortega J, Navarro-Pulido A, et al. Consensus document on dog and cat allergy. Allergy. 2018;73(6):1206-1222. doi:10.1111/all.13391
  6. Schoos AM, Nwaru BI, Borres MP. Component-resolved diagnostics in pet allergy: Current perspectives and future directions. J Allergy Clin Immunol. 2021;147(4):1164-1173. doi:10.1016/j.jaci.2020.12.640