Children who live with dogs and cats are less likely to develop allergies to those animals later in life, but only if the pet is under the same roof while the child is still an infant, a new study suggests. Compared to babies born into cat-free homes, those who grew up with cats were roughly half as likely to be allergic to them as teenagers, the study found. Growing up around a dog reduced the risk of dog allergies by about the same amount for boys, but not for girls — a finding that mystified researchers. Being exposed to pets anytime after the first year of life appeared to have no effect on allergy risk, however, which indicates that timing may be everything when it comes to preventing allergies. (More on Health.com: 15 Hypoallergenic Dogs and Cats) Though they can’t say for sure, the researchers suspect that early exposure to pet allergens and pet-related bacteria strengthens the immune system, accustoms the body to allergens, and helps the child build up a natural immunity. “Dirt is good,” says lead researcher Ganesa Wegienka, Ph.D., summing up the theory. “Your immune system, if it’s busy with exposures early on, stays away from the allergic immune profile.” This isn’t the first study to find that having a household pet may protect kids from allergies, but it is the first to follow children until they were 18 years old. (More on Health.com: How to Reduce Pet Allergens at Home) Previous studies have had mixed results — some have even linked pet exposure during infancy to an increased risk of allergy — so it’s too early to recommend getting a dog or cat just to ward off allergies in your infant, says David Nash, M.D., clinical director of allergy and immunology at the Children’s Hospital of Pittsburgh. “In the end, we’ll probably find out that there are periods of opportunity when exposure to allergens, for some people, is going to have a protective effect,” says Dr. Nash, who was not involved with the new study. “But … Continue reading Study: Living With Pets May Protect Infants From Allergies