What Is Pet Dander?
Pet dander is composed of tiny, even microscopic, flecks of skin shed by cats, dogs, rodents, birds and other animals with fur or feathers. These bits of skin can cause reactions in people who are specifically allergic to these triggers.
Additional allergy triggers or allergens come from sources other than the animal's skin. Proteins found in saliva, urine and feces from cats, dogs and other pets can cause allergic reactions in some people. The most common allergies are caused by the Fel d I protein from cats and the Can f I and Can f II proteins from dogs. Dried saliva containing allergens may flake off from an animal's fur and become airborne, where it is inhaled by the allergic person. Dust from dried feces can be suspended in the same way. 1
Which Animals Pose the Biggest Problems?
Cats are kept as pets in 27 percent of homes in the United States and dogs are found in 32 percent. However, roughly twice as many people report allergies to cats when compared to dogs. Research also indicates that male cats produce less Fel d I allergen than female cats, although the reason is not clear. 1
Animals with fur may be more likely to carry allergens from other sources, like dust, but the fur itself is generally not a trigger. For that reason, short-haired or hairless animals contribute dander and allergens to indoor air pollution just as effectively as long-haired animals do. There is no such thing as a non-allergenic dog or cat. 1
How Do Pet Allergens Occur?
Pet allergens are very light weight and small. They remain suspended in the air for a long time, much longer than allergens from cockroaches or dust mites. Because of their microscopic size and jagged shape, pet allergens easily stick to furniture, bedding, fabrics and many items carried into and out of the home. Animal dander is easily spread through the home and out to public places like schools and hospitals. 1 They can be found even in homes and buildings without pets. 1
How Do Pet Allergens Affect Health?
Some people are allergic to pets or have asthma that is triggered by pet allergens. For these individuals, breathing animal allergens can make respiratory symptoms worse and lead to a decline in the ability of the lungs to function. The concentrations of an allergen required to cause a reaction vary greatly by individual. 1
People with allergies may experience upper and lower respiratory tract symptoms including congestion, sneezing, runny nose, chest tightness and wheezing. Other symptoms are itching, watery eyes, and eczema or rashes. 1
How Do You Control Pet Allergens?
For homes with sensitive individuals, the best way to protect indoor air quality is to remove the animal from the home. However, pet allergens may stay in the home for months after the pet is gone because the allergens remain in house dust. Allergy and asthma symptoms may take weeks or even months to improve. 1
If the pet stays in the home, keep it out of the bedroom of anyone who has asthma or allergies. Do not allow the pet on furniture, especially upholstery, and keep the pet away from carpets. Clean the home often and do not allow dust to accumulate.
- Institute of Medicine, Division of Health Promotion, Indoor Air and Disease Prevention. Clearing the Air: Asthma and Indoor Air Exposures. Washington, D.C.: National Academies Press, 2000. Kanchongkittiphon W, et al. Indoor Environmental Exposures of Asthma: An Update to the 2000 Review by the Institute of Medicine. Environmental Health Perspectives. 2015; 123: 6-20.
- U.S. Environmental Protection Agency. Asthma Triggers: Gain Control: Pets. Accessed August 26, 2015.
Reviewed and approved by the American Lung Association Scientific and Medical Editorial Review Panel. Last reviewed December 7, 2017.
Page Last Updated: July 1, 2019