Ganesa Wegienka, MS, PhD, and team monitored a group of children from the day they were born through to adulthood. The children and their parents were regularly contacted regarding their exposure to dogs and cats.
When 565 of them reached the age of 18 years, blood samples were taken and tested for antibodies to cat and dog allergens.
The scientists found that exposure to a specific pet during the child's first year of life was the key exposure period. In some groups, this exposure was, in fact, protective.
Young adult males who were exposed to dogs during their first 12 months of life had a 50% lower risk of becoming sensitized to dogs compared to young adult males who had no dog in the house during the same period.
Adult males and females were much less likely to be sensitized to cats if they lived with a cat in the house during their first 12 months of life, compared to peers who did not have a pet cat during the same period.
"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."
"Lifetime dog and cat exposure and dog- and cat-specific sensitization at age 18 years"
Wegienka G, et al
"Clinical & Experimental Allergy" DOI: 10.1111/j.1365-2222.2011.03747.x.