The association of pet keeping at home with symptoms in airways, nose and skin among Bulgarian children

Abstract

The role of pet exposure in early childhood for allergy/ asthma later in life is still controversial. Recently it was shown that 'avoidance behaviour' is an important factor for the pet distribution in the population. The aim of the present work is to study the association between self-reported pet keeping at home and symptoms in airways, nose and skin among children 2-7 years of age, in a country where primary prevention strategies regarding allergies are not common. A cross-sectional survey on the association between allergy and asthma symptoms and home environmental factors was conducted in two towns in Bulgaria in spring 2004 (the ALLHOME-1 study). Data for 4479 out of 12982 children was obtained. 21.3% of the parents reported having pets at the time of the questionnaire, and 23.3% for pet keeping at index child's birth. Parents of 3.3% of the children got rid of some of the pets and 10.6% refrained from having pets, due in both cases to allergic illness in the family. Keeping dogs or cats at the time of the survey or during the child's first years was associated with most of the symptoms (aOR 1.1-2.2).

Pet-keeping and its impact on asthma and allergies among preschool children in Shanghai, China

“…This might be due to Chinese culture in keeping fish and because the great majority of urban residences are apartments in areas of high population density, making fish-keeping more convenient. More Shanghai families (32.5%) demonstrated avoidance behaviors than that has been found In Sweden (27.3%) [17] and Bulgaria (15.0%) [18]. And the finding that children in families with avoidance behaviors had more asthma and allergies, agreed with those from Sweden and Bulgaria.…”

“…Compared to Sweden [17] and Bulgaria [18], Shanghai families had fewer furred pets, but more fish. People from the suburbs preferred dogs, while the majority of urban inhabitants raised fish.…”

“…There are more allergies, more furred pet avoidance behavior and less furred pet-keeping in families with allergies. Thus negative associations are found, and if avoidance behavior is not accounted for, it will confound the association between pet-keeping and children's health in a cross-sectional study, such that a "Healthy Pet-Keeping" effect would be erroneously reported [17,18]. Figure 2 shows our process of analysis and interpretation of results.…”

“…But some other studies revealed that the "protective" effect might be confounded by parental avoidance behavior or selection of particular pet species [10,16,17]. Still other studies have had different findings and concluded that petkeeping in the home is a risk factor for allergies [2,3,[17][18][19][20][21][22]. Risk factors which are not randomly distributed in the study population can be confounded by bias.…”

“…Family avoidance behavior of pet-keeping ("avoiding having pet" or "got rid of pet" due to allergies in the family) is one such possible confounder [23]. In Sweden [17] and Bulgaria [18], children in "avoidance" families were found to have more asthma and allergy, leading to the inference that pet-keeping may is "protective" in cross-sectional analyses. In Sweden [17], there had been a large campaign prior to the study to educate the general population about asthma, allergies and risk factors (The Allergy Year 1995).…”