Children who are raised in households with dogs during their first year of life may have a lower risk of asthma(哮喘)a few years later, a new study suggests. In the study, the researchers looked at early exposure to dogs and farm animals and the rate of asthma among about 276,000 school-age children in Sweden. Among the school-age kids in the study, those who had been exposed to dogs during their first year of life were 13 percent less likely to have asthma at age 6. The researchers said they don’t know for sure what exactly may explain the relationship between early exposure to anim