Milwaukee ? Infants who have a certain gene and live with a dog have stronger immune systems than those who don’t and are less likely to develop allergies or eczema, a University of Wisconsin-Madison research study shows.

However, the authors warn that the results are still preliminary and say that parents shouldn’t introduce pets into the household just to try to prevent potential allergies.

“We plan to continue to follow these kids to see if this is a long-term effect,” said James Gern, a pediatric allergist at the University of Wisconsin-Madison and author of the study.

“If you have eczema when you’re young, you’re more likely to develop allergies, but it’s really too early to tell if these kids will develop them,” he said.

For the study, the researchers followed 285 infants — each with at least one parent with allergies or asthma — from birth to age 1 and found eczema in 12 percent of the infants with dogs, compared with 43 percent of infants without the pet.

Furthermore, infants who had a specific variation of the CD14 gene — CD14-159TT — and who had a dog were less likely to develop allergies, the study showed.

Gern said that it was likely the dirt that dogs bring into the house was triggering the response.

The study is published in the Journal of Allergy and Clinical Immunology.