Persistent cat ownership and asthma in a longitudinal study of Puerto Rican youth

Epidemiologic studies have reported conflicting findings for cat or dog exposure and childhood asthma. No study has evaluated whether persistent pet exposure from early life to school age is associated with asthma or allergic sensitization in youth.

To evaluate whether persistent ownership of a cat or a dog throughout childhood is associated with asthma in Puerto Rican youth, a group disproportionately affected with asthma.

Prospective study of 384 youth who completed a baseline visit at ages 6 to 14 years and a second visit at ages 9 to 20 years. Persistent cat or dog ownership was defined as ownership of a cat or a dog in early life (during pregnancy or the first year of life) at either study visit (at school age). An allergen-specific IgE result was considered positive if more than or equal to 0.35 IU/mL. Logistic regression was used for the multivariable analysis of asthma and allergic sensitization.

In an analysis adjusting for household income, family history of atopy, persistent overweight or obesity, a persistent unhealthy diet, the time interval between study visits, and other covariates, persistent cat ownership was significantly associated with 68% reduced odds of asthma (95% CI for odds ratio = 0.11-0.92) but not with any allergic sensitization or sensitization to cat allergen. In contrast, persistent dog ownership was not significantly associated with asthma or allergic sensitization.

Among school-aged Puerto Rican youth followed for an average of 5 years, persistent cat ownership from early life to school age was inversely associated with asthma.