By Brian Sodergren
Laying waste to the prevailing opinion that pets and
children prone to allergies don't mix, a new study shows that
kids who grow up with dogs and cats in the home actually have a
significantly reduced risk of developing common indoor and
outdoor allergies.
The surprise finding was the result of a study which
followed hundreds of children from birth to nearly age seven,
and compared those exposed during infancy to cats or dogs to
those who were not exposed to these animals. Researchers found
that children exposed to two or more indoor pets were half as
likely to develop common allergies to such things as dust
mites, cats and dogs, grass, ragweed, and Alternaria, a fungus
found in air.
"We simply started looking at our data to see if exposure to
dogs and cats really increases the risk, and the data didn't
look the way it was supposed to. As a matter of fact, it was
very strongly the opposite of what we expected to find," said
Dennis R. Ownby (pictured above), M.D., chief of the Medical
College of Georgia's Section of Allergy and Immunology and lead
investigator on the study.
"Allergists have been trained for generations that dogs and
cats in the house were bad because they increased the risk of
you becoming allergic to them," Ownby continued. "We know that
before you become allergic to something, you have to be
repeatedly exposed to it."
Ownby, who called the findings "very significant," added
that the researchers predicted their conclusions would be the
exact opposite of what they actually found. "This contributes
to the mounting evidence that the things allergists have
believed for years, and parents have lived by, are wrong."
The news also offers hope to parents torn by the thought of
giving up their dog or cat because of pet allergens potentially
affecting their children.
"Hopefully this new research will really make people think
twice and be more tolerant of their pets before giving them
up," says Stephanie Shain, director of companion animal
outreach at The HSUS. "Far too many people relinquish their
pets prematurely, especially when allergies are involved. This
shows that maybe giving up your pet to spare your child isn't
the best medicine."
Researchers believe that children living with these animals
are probably exposed to higher levels of endotoxins, the
breakdown products of Gram-negative bacteria commonly found in
the mouth of a cat or dog. "Exposure to endotoxins is thought
to force the body's immune system to develop a different
pattern of response that makes you less likely to become
allergic," Ownby said.
Allergies affect approximately 15% of the population, and
while all cats and dogs are allergenic (allergy-causing) to
people allergic to animals, cats tend to be more allergenic
than dogs. Also, contrary to popular belief, there are no
"non-allergenic" breeds of dogs or cats; even hairless breeds
may be highly allergenic.
People's allergies act up around cats and dogs because of
glands in the animal's skin that secrete tiny
allergy-triggering proteins, called allergens, that linger in
the animal's fur, but also float easily in the air. Allergens
are present in the animal's saliva and urine, and may become
airborne when saliva dries on the fur. The severity of reaction
to these allergens varies from one person to the next, ranging
from mild sniffling and sneezing to life-threatening asthma,
and can be complicated by simultaneous allergies to other
irritants in the environment.
"The bottom line is that maybe part of the reason we have so
many children with allergies and asthma is we live too clean a
life," Ownby said. "What happens when kids play with cats or
dogs? The animals lick them. How many cute pictures like that
have you seen? The lick is transferring a lot of Gram-negative
bacteria, and that may be changing the way the child's immune
system responds in a way that helps protect against
allergies."
For more information and tips on alleviating pet allergies
at home, read "Coping with Allergies to Pets" at the link
below.
Brian Sodergren is an Issues
Specialist in The HSUS's Companion Animals Outreach
section.
