Animal Allergies

While pets are wonderful additions to a household, they can cause allergic reactions in those who are sensitized to animal allergens. The most common animal allergies are to cats and dogs, but any warm-blooded pet, including small rodents, birds, rabbits, cows, and horses can cause problems.

Most animal allergens circulate throughout a house as small microscopic particles, invisible to the human eye. Cat allergen, for example, can come from the saliva, fur, body secretions, or skin and is only about two microns. As a comparison, the cross-section of a human hair is 100 microns. Regular resting sites of animals like carpets, couches, and beds generally have a significant allergen build-up.

People are not allergic to an animal’s hair, but to an allergen found in the saliva, dander (dead skin flakes) or urine of an animal with fur. Usually, symptoms occur within minutes.

For some people, symptoms build and become most severe eight to 12 hours after contact with the animal. Others with more severe allergies can even experience reactions in public places if the dander has been transported on a pet owners’ clothing.

If avoidance is not possible, allergy shots have been shown to help. Some studies show they can help get rid of pet allergies in as much as 80% of patients.

Should Allergic Families Have Pets?

It is well accepted that furred pets contribute to allergic diseases such as allergic rhintis (hay fever), asthma, and atopic dermatitis (allergic eczema). We allergists often see patients who are experiencing sneezing and wheezing that is due directly to breathing in cat and dog dander particles. Symptoms can improve greatly with total avoidance of the pets, but patients are usually unwilling to part with their beloved animals.

Below are some additional tips for dealing with animal allergens within the home:

• Thoroughly clean the areas where the animal rests. Wear a dust mask when doing this.
• Washing and grooming the animal regularly outside of the house can reduce the allergen load in the house.
• Wash the animal’s bedding weekly in hot water (at least 130 degrees Fahrenheit).
• Follow the general dust control principles.
• Use multi-pleat extended surface filters in your heating system to eliminate airborne dander. HEPA filters placed in the bedroom can reduce nighttime exposure if the animal is kept out of the room at all times. Remember, however, that studies have shown that a cat placed in a room with a HEPA filter produces more allergen than the filter can remove.
• If possible, avoid visiting houses with pets. If you go to a house where there are pets, be sure to take your allergy and asthma medicines before you go. In addition, you should change your clothes after you leave, as soon as possible.

If the above environmental control measures don’t alleviate the symptoms, medications and/or allergy shots can be helpful.

But a very hot topic in allergy now is whether allergic families should have pets in their homes. To begin with allergies are genetically linked, that is, they run in families. Let’s use an example. If a parent has mild allergies to dust mite but not allergic to cats, is it o.k. for the parents to have a pet in the home as they bring up their children. Obviously, if the child develops allergies to an animal, then the avoidance measures should be done.

However, several studies looking at large groups of people have found an interesting trend – that children born into a house with a pet were somewhat LESS likely to become allergic than those children born into a house without pets. No one knows why this may occur, but the two main theories are:

1. High exposure to an immature immune system of an infant to animal allergens tends to tune down the allergic process.

2. Exposure to tiny amounts of animal waste products distract the infants immune system, and direct it toward non-allergic activities.

There have been several studies in the past that showed that high exposure of infants to dust mite lead to more allergies, suggesting that there is something different about animal allergens and dust mite.

Also, a study in the May 2002 issue of “Epidemiology” showing that older children were MORE likely to develop asthma if they had pets, especially dogs, in their homes. The study also showed that there was in increase in asthma with the use of humidifiers and having over four house plants in the house (suggesting that dust mite and mold avoidance may be important in prevention).

So, we are left with some controversy. It seems like infants may be protected from developing allergy if they are brought up in a home with pets. Older children who don’t have allergies yet, may be more likely to develop them if animals are in the house. Consequently, we don’t know what to tell future allergic parents. Until more information comes out, most allergist are still recommending avoidance of furred pets (fish, birds, reptiles aren’t much of a problem). However, we all strongly recommend dust mite and mold avoidance measures in homes of potentially allergic children – that is, no carpeting, limiting the amount of house plants, and keeping the home cool and dry.

Are There Less Allergic Animals?

There are no “hypoallergenic” breeds of cats, dogs, or any animal with fur. While it is ideal to remove the pet from the home and avoid contact if you’re highly allergic, we realize this is not an option for some.  If allergic and an animal is indoors, keep the pet out of the bedroom and other rooms where you spend a great deal of time. While dander and saliva are the sources of cat and dog allergens, urine is the source of allergens from rabbits, hamsters, mice and guinea pigs. Ask a non-allergic family member to clean the animal’s cage.

Don’t suffer from untreated allergies. Schedule an appointment today with one of our board-certified allergists, and move towards a clearer tomorrow.