Detectable levels of dog and cat allergens are present in every home — even in those with no pets, according to a study from the NIEHS and the U.S. Department of Housing and Urban Development. Although allergen levels predictably were higher in homes with an indoor dog or cat, levels previously associated with triggering an allergic reaction were also common in homes without the pets.

Since dog and cat allergens can be transported on clothing, the researchers theorized that communities, particularly those in which dog or cat ownership is high, may be an important source of these pet allergens.

But when you and your family — like many millions of others — own a furry or feathered pet or two and it appears to be a trigger to your child's asthma, what should you do? A preventive strategy would be to remove your pets from your home if possible. If this cannot be done, make it a policy to keep pets confined to a specific area of the home not used often by the child and to keep pets completely out of your child's bedroom — especially his bed.

Also keep in mind that your child can wheeze and cough with and without your pet being present. While an animal may be out of sight, their allergens may not be because pet allergens are carried on very small particles. As a result, pet allergens can continue to circulate in the air and remain on carpets and furniture for weeks and months long after a pet is gone.

If you keep your pet in your home, consider confining it to certain rooms or areas. And, if possible, bathe pets weekly to reduce the amount of allergens.

Also, remind your child after playing with a pet to wash his hands and clean his clothes to remove pet allergens. Around rodent cages, he should wear gloves to avoid contact with soiled litter cages. And, of course, dust and vacuum around pet areas often.