There have been a number of studies in the past investigating whether it is healthy for a baby to be around pets and whether such exposure increases or decreases risk of becoming allergic to them later in life.
In a recent study (published online June 2011), the researchers found that among males, those with an indoor dog during the first year of life had half the risk of becoming allergic to dogs at age 18 compared with those who did not have an indoor dog in the first year of life regardless whether born by C-section or vaginally. Also, teens with an indoor cat in the first year of life also had a decreased risk of becoming allergic to cats. Neither cumulative exposure nor exposure at any other particular age was associated with either outcome. So it appears that the FIRST year of life is key to whether a child develops pet allergies or not.
Although in this study, cat and dog ownership appears to be beneficial in kids, prior studies have suggested that for at least cats, it increases risk of overall allergies in children by 13 times! Dog exposure, however, reduces overall allergy by 4 times.
Lifetime dog and cat exposure and dog- and cat-specific sensitization at age 18 years. Clinical & Experimental Allergy Volume 41, Issue 7, pages 979–986, July 2011
Genetic and environmental risk factors for childhood eczema development and allergic sensitization in the CCAAPS cohort. J Invest Dermatol. 2010 Feb;130(2):430-7. Epub 2009 Sep 17
Opposing Effects of Cat and Dog Ownership and Allergic Sensitization on Eczema in an Atopic Birth Cohort. J Pediatr. 2011 Feb;158(2):265-71.e1-5.
*This blog post was originally published at Fauquier ENT Blog*