Baby's Exposure to Pets May Protect Against Allergies

Having a family pet is not likely to increase a child’s risk of developing pet allergies. In fact, new research suggests that early exposure to Fido and Fluffy may actually protect youngsters against developing such allergies later in life.

According to the study report that was recently published in the journal Clinical & Experimental Allergy, exposure to pets during an infant’s first year of life appears to provide the greatest protection. Lead study author Ganesa Wegienka, Ph.D., of Henry Ford Hospital in Detroit noted, “Exposing children to cats and dogs in the home is not going to increase the risk of sensitization to these animals. It might even decrease the risk.”

Findings of the analysis revealed that infant boys who lived with a dog in their home had their risk for developing an allergy to dogs by the age of 18 cut in half, but no such association was seen among girls. However, among those infants who lived in homes with cats, the risk of allergies was reduced by about 48 percent for both infant boys and girls.

Another interesting finding of the analysis showed that both males and females delivered by Cesarean-section had a 67 percent less likelihood of developing a dog allergy when a dog was present in the home during their first year of life. Wegienka said that this may be due to the fact that babies born by cesarean section are not exposed to the diverse microflora that babies born vaginally are.

Whether exposure to animals increases the likelihood of developing allergies, or if exposure to pets helps build immunity to pet dander and bacteria, has remained a subject of ongoing debate. Wegienka and colleagues set out to determine what effects of childhood exposure to cats and dogs had on the risk of pet allergy development.

For their study, the researchers analyzed blood samples of more than 500 children taken during the Detroit Childhood Allergy Study from 1987 to 1989 that followed participants from birth. The focus of the analysis was to look for the presence of an antibody known as animal-specific IgE, which would indicate that a child was sensitized to that animal. In addition, follow-up among children in the study at age 18 included additional blood samples and pet histories. The histories indicated that 184 participants had a dog, and 110 of the children had a cat, during their first year of life.

Wegienka pointed out that the study does not definitively indicate that having a family pet will prevent infants from developing allergies later in life, as it only found an association between a reduced risk for allergies and exposure to cats and dogs at an early age. Wegienka cautioned, “We don't want to say that everyone should go out and get a dog or cat to prevent allergies.” She then added, “More research is needed, though we think this is a worthwhile avenue to pursue. How does having a dog or a cat change the home environment? And, how does that affect allergy risk?"

The American Academy of Allergy, Asthma and Immunology estimates that up to 70 percent of American homes have family pets. Pet allergies can cause a range of mild to moderate symptoms that may include a runny nose and sneezing, and itchy or watery eyes. However, for some individuals, pet allergies can lead to severe reactions such as deadly asthma attacks.