Do asthma and allergy influence subsequent pet keeping? An analysis of childhood and adulthood.
BACKGROUND
Asthma and allergy might influence the choice of keeping pets, leading to apparent protective effects of pets on allergic disease.


OBJECTIVE
We investigated the effects of asthma and allergy on subsequent pet keeping in childhood and adulthood.


METHODS
Information about asthma and pet keeping at ages 0 to 4, 5 to 15, 20 to 44, and 26 to 56 years was provided by 9812 subjects participating in the 9-year follow-up of the European Community Respiratory Health Survey.


RESULTS
In childhood asthma debut at younger than 5 years was associated with less cat keeping at 5 to 15 years (odds ratio [OR], 0.60; 95% CI, 0.44-0.82), an effect only observed when the parents did not have asthma or allergy (P(interaction) = .045). Childhood asthma did not influence adult pet ownership, unless there were adult symptoms. Adults less often acquired cats at follow-up if they had 3 or more asthma symptoms (OR, 0.78; 95% CI, 0.64-0.95), were taking asthma medication (OR, 0.48; 95% CI, 0.31-0.74), had hay fever (OR, 0.75; 95% CI, 0.62-0.91), had atopy (OR, 0.75; 95% CI, 0.61-0.91), or had specific IgE to cat (OR, 0.57; 95% CI, 0.39-0.82) at baseline. Adults who already had pets usually continued keeping the same type of pet, except that the presence of 3 or more asthma symptoms was associated with less subsequent dog keeping (OR, 0.69; 95% CI, 0.53-0.89). Pet removal between surveys to reduce allergen was reported by 4.7%.


CONCLUSIONS
Selective avoidance subsequent to asthma or allergy was observed for childhood cat keeping and adult cat acquisition. Avoidance would produce an apparent protective effect of cats on childhood asthma (large OR, 0.83). Avoidance was generally not observed for dogs or birds.


CONCLUSIONS
A part of the protective effects of childhood cats on asthma and allergy can be attributed to selective avoidance.
Svanes
Cecilie
C
Department of Thoracic Medicine, Institute of Medicine, University of Bergen, Norway. cecile.svanes@med.uib.no
Zock
Jan-Paul
JP
Antó
Josep
J
Dharmage
Shyamali
S
Norbäck
Dan
D
Wjst
Matthias
M
Heinrich
Joachim
J
Jarvis
Deborah
D
de Marco
Roberto
R
Plana
Estel
E
Raherison
Chantal
C
Sunyer
Jordi
J
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000485:Allergens / Q000276:immunology*; D000818:Animals; D000829:Animals, Domestic / Q000276:immunology*; D001249:Asthma / Q000453:epidemiology* / Q000276:immunology*; D001717:Birds; D002415:Cats; D002648:Child; D002675:Child, Preschool; D004285:Dogs; D005060:Europe / Q000453:epidemiology; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008137:Longitudinal Studies; D008875:Middle Aged
D000485:Allergens