Young children who share their home with dogs or cats in the first year of life are half as likely to become allergic to those animals than kids who grew up with no pets.
The finding flies in the face of advice given out by pediatricians and allergists for the last three decades, lead researcher Dr. Dennis R. Ownby of the Medical College of Georgia in Augusta stated. Conventional wisdom has held that having a pet increases a child's risk of developing an allergy to that animal.
"Evidence is mounting that the opposite is true," Ownby said. He added that, "surprisingly," exposure to dogs or cats also seems to cut the risk of developing other common allergies, such as sensitivity to dust mites and pollen.
While Ownby isn't calling for everyone with newborns to rush out and get two pets, he says the new findings should allow parents who already have pets to breathe a sigh of relief.
"These parents don't have to feel guilty that they are increasing their child's risk for allergies or asthma."
Researchers at Sahlgrenska University Hospital in Goteborg, Sweden, studied data on 2,500 Swedish children and found that children exposed to pets during the first year of life had a lower rate of allergy rhinitis at ages 7 to 9 and lower rates of asthma at ages 12 to 13.
Researchers found that 3.3 percent of children exposed to pets during infancy had asthma at age 12 to 13 compared with 8.5 percent of children who had no exposure to household pets.
The study also found that children with early exposure to cats showed nearly half the rate of cat allergy when they were adolescents compared with kids not exposed to cats when they were babies.
Led by Ganesa Wegienka, MS, PhD, of the Department of Public Health Sciences, Henry Ford Hospital, researchers recently followed a group of children from birth until they reached adulthood. Periodic contact was made with the parents and the children to collect information about exposure to cats and dogs.
At age 18 years, 565 study participants supplied blood samples to the researchers, who measured antibodies to dog and cat allergens in the samples.
Results found that being exposed to the specific animal in the first year of life was the most important exposure period, and the exposure appeared protective in some groups.
Young men whose families had kept an indoor dog during their first year of life had about half the risk of becoming sensitized to dogs compared to those whose families did not keep a dog in the first year of life.
Both men and women were about half as likely to be sensitized to cats if they had lived with a cat in the first year of life, compared to those who did not live with cats.
"This research provides further evidence that experiences in the first year of life are associated with health status later in life, and that early life pet exposure does not put most children at risk of being sensitized to these animals later in life," Wegienka concludes.