BACKGROUND

DISCUSSION

 Timing of exposure may be a factor in study results involving asthma as exposure to dogs early in life may play a bigger part in development of asthma than later life dog exposures.

  It has been strongly suggested that pet allergen exposure itself may not be the protective factor, but rather the endotoxin exposure that is carried into homes of pet owners that may provide the protective effect.

  In a population where asthma has increased and sensitization to cat allergens is the strongest risk factor for incidence of physician-diagnosed asthma, owning a cat is associated with a decreased risk of asthma.

  If owning a cat decreases the risk of sensitization, and sensitization (rather than exposure) is the primary risk factor for asthma, then we might expect that pet ownership would be too closely related to allergy and therefore not show an independent protective effect against asthma in multivariate analysis.

  Dog ownership, a source of residential exposure to endotoxin, may deteriorate the affiliation between air pollution and respiratory symptoms in asthmatic children.   Limited or suggestive evidence specifies that several measures short of removal (e.g., cleaning the animal) may result in temporary reduction in allergen levels.   Data on the efficacy of interventions for other animals are insubstantial to draw informed conclusions.   Previous studies have suggested that exposure to pets may have a protective effect against allergies but many of these studies were based on retrospective questioning of subjects about their exposure.

STUDY FINDINGS OBJECTIVE

ASSOCIATION BETWEEN EXPOSURE TO CATS AND DOGS AND RISK OF ASTHMA Brian Kunkle MPH, Dr. Janvier Gasana MD PhD, Karina Villalba, Michael Melchior MPH, Rakesh Nair, and Shiryn Sukhram MPH

Department of Environmental and Occupational Health, Robert Stempel School of Public Health Florida International University, Miami, FL

FUTURE RESEARCH

  Future studies on dogs/cats and asthma need to include several time periods of exposure to dogs/cats in order to determine whether timing of exposure is important in risk for asthma.

  When significant levels are observed, the potential for lowering exposure should be investigated.

  Researchers suggest prospective studies to provide more reliable result.

  Focus on asthmatic children who are already sensitized to or symptomatic with exposure to cats and dogs.

  Research is needed to assess the level of animal allergen exposure (cat and dog) in day care centers and schools.