Can Pets Help Prevent Your Allergies?

When Megan Jensen of Cincinnati, Ohio, found out she was pregnant with her first child, she and her husband were elated. “After our initial excitement, however, we wondered if we’d have to get rid of our two cats, Pepper and Penny, since we’d heard that pets might cause or aggravate allergies in children. The cats have been with us for 5 years, and the thought of having to give them up just broke my heart,” Megan recalls. “We weren’t sure what to do.”

Lisa Nelson of Kalamazoo, Michigan, went through a similar dilemma. “Our cocker spaniel, Muffin, was definitely an important part of our family,” Lisa says. “We couldn’t bear the thought of giving him up when our new baby came along. We talked to our family doctor and Muffin’s veterinarian, and they told us that exposure to Muffin might even help prevent our new baby from developing allergies. Our son, Jake, is now 3 years old and has never shown any signs of allergies—and he and Muffin are inseparable.”

BABIES AND PETS: A GOOD COMBINATION?
Often, when families with pets welcome new babies into their homes, they wonder if they should give up their dogs or cats just in case the baby develops an allergy to the pets. Many families that have been thinking about adopting a dog or cat from their local shelter might not follow through because of the fear that the pet might make their children’s allergies worse. Past research indicated that having pets contributed to the risk of becoming allergic to them, especially in children. However, several recent studies have shown that pets may actually help prevent allergies in children more than they cause them. These studies indicate that cats and dogs may not increase a child’s risk of developing allergies as we previously thought—our four-legged friends just might help decrease the risk of developing them, which is great news for pet lovers who are agonizing over whether or not to give up their pets when a new baby arrives.

“Ever since I can remember, the story always went that if you had allergies, having pets was usually not a good idea,” says Dr. Larry Cohen, a veterinarian at the Village Animal Hospital in Larchmont, New York. “The increased dander, exposure to multiple allergens, and close contact of people and their pets was thought to make a difficult medical situation worse. But that thought process may be changing.”

SOME INTERESTING FACTS
Conventional wisdom says that in order to become allergic to something, you have to be repeatedly exposed to it. But some exciting new studies are beginning to challenge that idea, and researchers believe it may be due to endotoxins, or products of bacteria, that are found in the mouths of cats and dogs. These studies are showing that as children are exposed to these endotoxins, they begin to develop immunity to certain allergens and build up a tolerance to them.

Several studies have been conducted in Europe and the United States to take a close look at the effect that pets have on allergies in children. One study, from researchers at the Med­ical College of Georgia and published in the Journal of the American Medical Association, tracked a group of 474 healthy babies between 1987 and 1989. The children were followed until they were approximately 7 years old, when they were given skin prick tests for dog, cat, dust mites, ragweed, and bluegrass allergies. Blood tests were also done to look for antibodies called immunoglobulin E that indicate an allergic response to some sort of allergen. The researchers came up with some surprising results: Almost 39 percent of the children who grew up in a household with no pets had the antibodies; 41 percent of children that lived in a home with one pet had the antibodies; and 18 percent of the children who grew up in homes with at least two pets had the antibodies. These results indicat­ed that the more pets, the bet­ter—the researchers found that the children with two or more pets had a 77 percent lower risk of having the antibodies, meaning that they had fewer allergic reactions than the children who had one or no pets. The researchers also found that having pets in the first year of life may reduce the risk of developing allergic reactions not only to pets but also pollen, grasses, mold, and dust mites. The study concluded that children living in a house with two or more dogs or cats during the first year of life may develop allergies less frequently when compared to children raised without pets.

Another study, conducted by Swedish researchers at the University of Virginia and published in The Journal of Allergy and Clinical Immunology, tracked nearly 2,500 children in Sweden. The children were tested for allergies when they were 7 or 8 years old and tested again 4 years later. The study found that children who continually had pets in their homes were less likely to have pet dander allergies than children who had just acquired a pet or who had only been exposed to pets as babies. Eighty percent of the children who tested positive to allergens associated with cats never even had a pet cat at home when they were growing up. “Everyone agrees that exposure to allergens during the first year of life has, along with heredity, a profound influence on the risk for allergies later on,” says Dr. Cohen. “The question now is: Does exposure to cats and dogs increase this risk, or, as these studies show, decrease it?”

NOTHING IS CONCLUSIVE...YET
Studies are continually being conducted on this subject, and while it looks promising, nothing is conclusive enough to recommend bringing pets into your home to prevent allergies. But it should certainly make you think twice if you’ve been considering giving up your pet prior to the arrival of a new baby. If you’re an adult who already has allergies, bringing a pet into your home won’t make a difference—none of these studies show any reason to believe that pets can help decrease the effects of existing allergies. The best thing you can do is talk to your veterinarian and your family doctor about these recent studies, and they can help guide you as to what is best for you and your family. If anything, these studies reinforce the idea that pets have the power to enrich our lives in ways that we may have never thought possible.

FACTS ABOUT ANIMALS AND ALLERGIES

• More than 50 million Americans suffer from allergies each year.
• Household pets are the most common source of allergic reactions to animals.
• Proteins secreted by oil glands in an animal’s skin and proteins found in an animal’s saliva, not an animal’s fur, provoke pet allergies.
• Cats are more likely to cause allergic reactions than dogs because they lick themselves more often and spend more time indoors.
• Guinea pigs, gerbils, mice, and rats can cause allergic reactions in people.
• Allergies to animals can take two years or more to develop.

For more information on pets and allergies, visit the National Institute of Allergy and Infectious Diseases Web site at www.niaid.nih.gov.

THE NEW STUDIES AT A GLANCE
Recent studies have shown an interesting link between early exposure to pets and a decrease in the risk of developing allergies. While none of these studies are conclusive and additional research still needs to be done, they have shown that:

• Having pets in the first year of life may reduce the risk of developing allergic reactions not only to pets but also pollen, grasses, mold, and dust mites.
• Children living in a house with two or more dogs or cats during the first year of life may develop allergies less frequently when compared to children raised without pets.
• As children are exposed to the endotoxins found in the saliva and oil glands of cats and dogs, they begin to develop immunity to certain allergens and build up a tolerance to them.
• Having more than one pet in a household can lower the risk of developing allergies in small children.
• Children who continually had pets in their homes were less likely to have pet dander allergies than children who had just acquired a pet or who had only been exposed to pets as babies.