Pet Allergy


According to published studies, between 10-15% of the general population are allergic to cats and dogs. This high incidence of animal allergy, coupled with the fact that approximately 50-70% of homes have a dog or cat living indoors, makes pet allergy a major health consideration. It has been estimated that of the two million people allergic to cats, at least 1/3 of them live with at least one cat in the home. And, to make matters worse for the allergic individual, many homes where there are no indoor pets will still contain enough allergenic pet proteins to cause allergic reactions.

Pet Allergy Causes

Allergy to cats is twice as common as allergy to dogs. Regardless of the animal or species, it is likely that the cause of the allergic reaction is not the hair or fur at all.  One highly allergenic source is the dander or old skin scales of the animal. These particles are deposited wherever the pet goes - on the bed, the couch, and in the carpet. 

Dander allergens are extremely small and easily become airborne, eventually depositing themselves and clinging to furniture, draperies, wall coverings, and even the walls themselves. Because of its stickiness, the allergenic dander can remain in the house for six to twelve months or longer after the animal has been removed from the house.  In cats and dogs, saliva and urine are also potential sources of allergens. They are deposited on the fur through licking and urination. When the hair or fur dries, the microscopic particles flake off, become airborne, and become readily accessible to the airway of the allergic individual.  The major cat allergen is called Fel d 1, and is formed in the sebaceous glands of the skin and is present in saliva. Fel d 1 is deposited on the fur from sebaceous gland secretions and through saliva when cats lick themselves clean. The major dog allergen has been identified as Can f1.

Pet Allergy Symptoms

Some people who are allergic to animals will begin to have symptoms immediately upon entering a home or room where a pet resides. Symptoms might include the acute onset of itchy, watery eyes, itchy nose and throat, sneezing, runny nose, and nasal congestion. Even asthma symptoms, including coughing, wheezing, tightness of the chest, and difficulty breathing can be induced almost immediately upon exposure.

Unfortunately, if one is sensitive enough, it does not take a lot of animal dander to cause an allergic reaction. The allergen is so small and light that it remains airborne for long periods of time, making it readily available to be breathed in and begin causing a problem.On the other hand, many pet allergic individuals will not react acutely when exposed to an animal. Because of constant exposure, they may react, over time, by having daily, chronic symptoms such as persistent nasal congestion, runny nose, itchy eyes, nose, and palate, as well as coughing, wheezing, or shortness of breath.

Are Certain Dogs and Cats “Non-allergenic”?

Unfortunately, there are no known breeds of either cats or dogs that do not produce allergenic dander. It must be remembered that allergies can also be produced by exposure to proteins in pet hair, saliva, and urine. Therefore, every cat or dog has the potential for causing allergies. Patients often comment that “I am allergic to my neighbor’s cat or dog, but I am not allergic to my own”. This may be explained by some species differences, or possibly due to some desensitization which may have taken place with one’s own pet.

Bottom line: If you are allergic to dogs or cats, it is not advisable to own one, even if it is from a species that reportedly produces less allergen.

Pet Allergies in the Home of a Non-pet Owner

Even if you have never had an indoor pet, it is likely that you have detectable pet allergen in your home, and maybe even enough to be causing chronic respiratory symptoms. Since dander is very small, light, and sticky, it can attach itself to your or your child’s clothes and be deposited in your house unknowingly. And if one has outdoor animals, their allergens will inevitably be carried into the home by those who have direct contact with the animal, especially children.

An important fact to remember is that many school classrooms have dog and cat allergens in high enough concentration to cause allergic reactions.  It has also been reported that in some school classrooms, there is as much cat and dog allergen as in homes where cats and dogs reside!

Pet Allergy Treatment

The cornerstone of allergy treatment is to avoid or minimize exposure to known allergens to the maximum degree possible. Therefore, when an allergy specialist confirms the diagnosis of pet induced allergy, the doctor has the difficult task of making it clear that the patient will likely continue to have allergic reactions as long as the pet remains in the home. Recommending that the pet be removed from the home can be a difficult task, as families become emotionally attached to their pets, and the pet is commonly described as “a member of the family”. Most doctors know that family pets often win out and remain in the home, so the doctor can only suggest the best ways to live with the pet.

If the pet does remain in the house, it is not unreasonable for the allergist to insist that the animal never come in the bedroom of the allergic sufferer. This “compromise” can be helpful, although generally not curative. The allergic individual should endeavor to create a totally allergy free zone in his or her bedroom, the room where one spends a great percentage of their life.

Removing Pet Dander From The Home

The bedroom of a pet allergic individual should be cleaned frequently. All hard surfaces in the bedroom should be wiped with a moist cloth to remove the small and sticky animal dander which has likely adhered floors, carpets, walls, furniture, ceiling fans, lamp shades, and even ceilings. In addition, every part of your home, especially the bedroom, should be vacuumed with a HEPA vacuum cleaner. If you have hard surface floors, they should be mopped weekly. In addition, it may be helpful to run a HEPA air cleaner in the bedroom. Pets should be washed or treated with a dander removal product every two weeks. This removes much of the allergenic dander from the fur before it becomes airborne.



Allergy and Asthma Newsletter
Would you like to receive the latest allergy information or asthma information from The Online Allergist? Enter your email below to sign up for our informative Asthma and Allergy Information newsletter.

Social Media
The Online Allergist is venturing into the world of Social Media. If you are looking for asthma or allergy information or if you'd like to ask The Online Allergist a question on Twitter or Facebook, you can do so by clicking the logos below.

The Online Allergist - Allergy Information on Twitter The Online Allergist - Allergy Information on Facebook