Dog and Cat Dander Can Make Allergies Worse in Winter

Dogs and cats. They may be your best friends. But if you have allergies they could be your worst enemy, especially this winter. As the weather gets colder and dogs and cats spend more time inside, the level of animal dander rises in the home.

"The major problem is two-fold," says Richard Weber, MD, a National Jewish Medical and Research Center allergist. "The first concern is that it's cold and the house is closed up. The second is with homes being 'tighter' and less drafty than they have been in the past, there's less fresh air coming into the house."

Because new houses are built to a high level of energy efficiency and older homes are being updated, the amount outside air exchanged with inside air is dropping dramatically in homes throughout the United States.

"The upside is that you're being energy-efficient," he says. "The downside is your breathing the same air over and over, and allergens do build up in the house."

A forced-air furnace also can increase problems because it recirculates dander-laden air throughout the home. Changing the furnace air filter regularly--and closing the vent and door, and keeping animals out of the bedroom of the person with allergies--can help relieve allergy symptoms. Making a secondary filter from a piece of muslin or cheesecloth and taping it to the inside of the vent in a room may remove some allergens, as well. Other tips include having fewer knick-knacks in the home to collect dust, and purchasing mattress and pillow covers.

Heated air also creates a considerable drop in humidity in the home. People using humidifiers during the winter should clean them weekly with a solution of bleach and water to kill mold. Never allow humidity in the home to rise above 40 percent. At higher concentrations, dust mites, which cause allergies, begin to thrive and the possibility of mold contamination increases dramatically.