Introduction
According to the National Center for Biotechnology Information, allergies to dogs and cats affect 10-20% of the population worldwide and are a growing public health concern as these rates continue to rise.
This article compares and contrasts dog and cat allergies. Many people wonder whether cats or dogs are more problematic for allergies. We’ll cover the causes, symptoms, and management of allergies to both pets to help determine which may be worse for allergy sufferers.
Allergy Basics
An allergy is defined as an overreaction of the immune system to a substance that is harmless to most people [1]. When exposed to an allergen, the body’s immune system treats it as an invader and releases chemicals like histamine to defend against it. This triggers allergy symptoms.
Common allergy symptoms include [1]:
- Sneezing
- Itchy, watery eyes
- Runny nose
- Nasal congestion
- Itchy throat or roof of mouth
- Coughing
- Rashes or hives
The most common allergy triggers are [2]:
- Pollen
- Dust mites
- Mold
- Pet dander
- Insect stings
- Foods like nuts, eggs, or shellfish
- Medications like penicillin
[1] https://www.webmd.com/allergies/allergy-basics
[2] https://asthmaandallergies.org/asthma-allergies/allergy-basics/
Cat Allergens
The main allergen in cats that causes allergic reactions in humans is a protein called Fel d 1. This protein is produced primarily in cats’ skin glands and is also present in their saliva, urine, and fur (1).
Fel d 1 can be found throughout a cat’s fur, but especially in places where their scent glands are located, like around their head, chin, tail, and paws (2). The protein is extremely lightweight and sticky, so it easily spreads through the air and attaches to fabrics and other surfaces (1).
When a cat grooms itself by licking their fur and skin, the Fel d 1 on their bodies gets transferred to their saliva. It then dries into microscopic particles that become airborne or fall onto surfaces. These particles can remain potent allergens for many months if not cleaned up (2). This is why cat allergens are so ubiquitous in homes and other spaces where cats live and visit.
Even homes without cats can contain significant levels of Fel d 1 that have been carried in on people’s clothes or otherwise transferred from other environments (1). Some studies have detected cat allergens in 100% of sampled homes, schools, and workplaces regardless of pet ownership (2).
Sources:
(1) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4794606/
(2) https://www.jacionline.org/article/S0091-6749(98)70003-7/fulltext
Dog Allergens
The main dog allergen is Can f 1, which is a protein found in dog saliva, dander, and urine. Can f 1 is produced in the salivary glands and coats the fur when dogs lick and groom themselves. It can become airborne when it dries and flakes off the fur. It is very lightweight and can remain airborne for long periods. This allows it to spread easily through homes with dogs. Even homes without dogs can have Can f 1 allergens present if people visit with their dogs. Can f 1 is sticky and highly allergenic, meaning it can trigger allergic reactions at low levels. Sources: [1]
Some key facts about Can f 1 allergen:
- Found in dog dander, saliva, and urine
- Produced in salivary glands and spread by licking/grooming
- Dries and flakes off fur, becoming airborne
- Lightweight and can stay airborne a long time
- Spreads easily throughout homes
- Sticky and highly allergenic
Controlling Can f 1 allergen levels is important for managing dog allergies. This includes bathing dogs regularly, using HEPA air filters, washing bedding often, and restricting dogs from certain areas. Those with dog allergies may still react to hypoallergenic breeds since they still produce Can f 1, just at lower levels.
Allergen Levels
Numerous studies have measured and compared the levels of Fel d 1 (cat allergen) and Can f 1 (dog allergen) in homes. A comprehensive study conducted by Arbes et al. analyzed dust samples from over 500 homes across the United States [1]. They found that Fel d 1 was detected in 90.9% of homes and Can f 1 was detected in 94.2% of homes. The median Fel d 1 level was 1.29 μg/g dust while the median Can f 1 level was 4.00 μg/g. This indicates that homes generally have higher levels of the dog allergen Can f 1 compared to the cat allergen Fel d 1.
However, there can be substantial variability between homes. Levels depend on factors like the number of pets, the breed, where pets are allowed, cleaning frequency, and ventilation. A study by Niesler et al. measured allergens in cars and found a wide range of Can f 1 and Fel d 1 levels that overlapped significantly [2]. They concluded that due to the wide variability between individual pets, it is impossible to declare that one species universally causes higher allergen levels.
Managing Cat Allergies
There are several strategies that can help reduce allergy symptoms for people who are allergic to cats but still want to keep their feline companions:
Bathing your cat weekly can significantly reduce levels of Fel d 1 allergen in the home, according to this Ohio State University veterinary guide. Use a cat-safe shampoo and wash your cat at least once a week.
HEPA air purifiers can remove cat allergens from the air. Place them in rooms where your cat spends the most time. HEPA filters should be changed regularly according to manufacturer instructions.
Over-the-counter antihistamines like cetirizine or loratadine can help relieve allergy symptoms. For more severe allergies, prescription medications may be needed. Consult an allergist to find the right treatment regimen.
Keep your cat out of bedrooms, and use high-quality HEPA vacuum cleaners when cleaning. Frequently washing bedding and soft furnishings can also cut down on allergens.
Managing Dog Allergies
There are several ways to help manage allergies for people who are allergic to dogs:
Frequent bathing of dogs can significantly reduce allergen levels. Bathing a dog at least once a week can remove allergens from their fur and dander. Be sure to bathe dogs outside or in a non-carpeted area to avoid spreading allergens in the home. Use a mild hypoallergenic shampoo. [1]
HEPA air cleaners can filter out pet allergens and dander from the air. Place HEPA filters in bedrooms and common areas. Be sure to change the filters regularly according to manufacturer recommendations. Portable HEPA air purifiers are also an option to filter air in specific rooms. [2]
Medications like antihistamines and nasal corticosteroid sprays can help relieve allergy symptoms from dogs. Oral antihistamines like cetirizine (Zyrtec) or loratadine (Claritin) can reduce sneezing, sniffling, and itching. Nasal sprays like fluticasone (Flonase) can reduce inflammation in the nasal passages. [3]
Hypoallergenic Breeds
Certain cat and dog breeds produce less of the Fel d 1 protein that triggers allergic reactions in humans. While no pet is 100% hypoallergenic, some breeds are considered lower allergen. Here are some of the most popular hypoallergenic cat and dog breeds:
Hypoallergenic cat breeds include:
- Siberian
- Balinese
- Oriental Shorthair
- Siamese
- Russian Blue
- Bengal
- Cornish Rex
- Devon Rex
- Sphynx
According to this source, Siberian, Balinese, and Oriental Shorthair cats produce less Fel d 1 protein than other breeds.
Hypoallergenic dog breeds include:
- Poodle
- Maltese
- Shih Tzu
- Bichon Frise
- Yorkshire Terrier
- Schnauzer
- Portuguese Water Dog
- Airedale Terrier
- Irish Water Spaniel
- Kerry Blue Terrier
According to this source, Poodles, Portuguese Water Dogs, and Schnauzers shed less dander and produce fewer allergens than other breeds.
Lifestyle Changes
Making some simple changes to your daily habits and home environment can significantly reduce allergy symptoms when living with pets.
One of the most important steps is to keep pets out of bedrooms and limit them to certain areas of the home. Pet dander and allergens easily get trapped in bedding, carpets, and fabric furnishings, leading to increased allergy symptoms. Designate your bedroom as a pet-free zone and do not allow them on beds or furniture.
It’s also crucial to wash your hands immediately after petting or playing with your pet. Washing hands regularly removes dander and allergens so you don’t spread them or touch your eyes and nose.
Other tips include keeping pets brushed and groomed regularly, wearing a mask when cleaning litter boxes or vacuuming, and using HEPA air purifiers and filters.
Conclusion
In summary, both cats and dogs can cause issues for people with allergies, but there are some key differences. Cats tend to produce more allergens than dogs, shedding smaller allergen particles that stay airborne longer. However, some allergy sufferers may react worse to dog allergens. There’s no clear winner in the cats versus dogs allergy debate.
The best recommendation is to spend time around the specific pet you’re considering before adopting. Allergy medication and other management strategies may allow an allergy sufferer to own a cat or dog. Hypoallergenic breeds produce fewer allergens, but are not allergy-free. Ultimately, each individual’s sensitivities and lifestyle must be weighed against their desire for pet companionship.
