Association between pet ownership and physical activity levels, atopic conditions, and mental health in Singapore: a propensity score-matched analysis

Pet ownership is commonly believed to provide health benefits, particularly in physical activity, mental health, and atopic conditions, but evidence is mixed and largely from Western or East Asian settings, with little data from Southeast Asia. Prior reviews (e.g., AHA statement) suggest dog ownership increases physical activity and that benefits may accrue cumulatively with age. In contrast, literature on mental health shows both improvements (e.g., increased social interaction, reduced stress/anxiety) and potential harms (e.g., higher psychoticism or depression in elderly, financial and caregiving burdens). For atopy (asthma, allergic rhinitis, eczema), studies conflict between protective desensitization effects of early exposure and increased allergen burden leading to worsening symptoms or higher diagnoses. With Singapore’s growing pet population and absence of local studies, this research aimed to evaluate the association between pet ownership and physical activity, mental well-being, and atopic conditions among Singaporean adults, and to explore heterogeneity across demographic and pet engagement subgroups.

The study reviews evidence indicating that dog ownership often correlates with higher physical activity (e.g., AHA statement; longitudinal and cross-sectional studies in older adults), with potential cumulative benefits over the life course and greater effects at older ages. Mental health findings are heterogeneous: some research reports reduced stress and anxiety, enhanced social interactions, emotional support, and increased social capital from pet companionship; other studies suggest possible exacerbation of psychological distress, higher psychoticism, and depressive symptoms among certain populations, and note burdens of pet care. For atopy, literature is split between protective effects via allergen desensitization and increased risks due to allergen exposure from pets. The review underscores gaps for Southeast Asia and the need to analyze effect modification by age, marital status, pet type, and caregiving roles.

Design and setting: Cross-sectional online survey of adults aged 21–64 residing in Singapore for at least 6 months, conducted over 11 days in February 2020. Exclusions: individuals requiring assistance in ≥1 ADL and owners of therapy/guide dogs. Recruitment via veterinary clinics, social media, messaging apps, email to NUS SSHSPH, and word-of-mouth. Questionnaire available in English, Chinese, Malay, Tamil; data collected anonymously via REDCap. Ethics approval by NUS SSHSPH DERC (SSHSPH-011) with waiver of written consent. Definitions: Current pet owner defined as co-residing with dogs, cats, small mammals (rabbits, guinea pigs, hamsters, gerbils, mice, chinchillas), or birds (excluding strays). Past pet ownership excluded current pets. Measures: Sociodemographics; medical history (hypertension, diabetes, hyperlipidemia; depression, anxiety, schizophrenia with option to decline mental health disclosures); detailed pet ownership history, number/types of pets; roles (owner, main caregiver); caregiving involvement for feeding, healthcare, activities, hygiene on 5-point Likert; overall pet attachment from 8 items adapted from CENSHARE/Pet Attachment Questionnaire (reverse-scored as needed), averaged to a 1–5 scale (close relationship >4). Physical activity: self-reported weekly minutes of mild, moderate, vigorous activity per HPB definitions. Mental health/general health: RAND SF-36 v1.0 subscales relevant to general and mental health domains, excluding physical functioning, role-physical, and pain. Atopic conditions: asthma, allergic rhinitis/conjunctivitis, eczema using adapted ISAAC and ECRHS II items for symptoms and formal diagnoses. Current and past pet owners with diagnosed atopy compared symptom severity on a 5-point Likert scale: while owning vs before ever owning; and after pet no longer around vs during ownership (3=no change; <3 worsening; >3 improvement). Data processing: Manual checks and statistical outlier detection (Cook’s distance); implausible entries (e.g., >1000 min/week moderate activity) excluded. Minimal missingness due to mandatory questions; complete-case analysis. Statistical analysis: Propensity scores estimated via logistic regression including age, race, marital status, housing, gender, past pet ownership, and marriage×housing interaction; model discrimination AUC 0.708 (bias-corrected 95% CI 0.672–0.743) and good calibration (Hosmer–Lemeshow p=0.452). 1:1 nearest-neighbor matching without replacement, caliper 0.25 SD of linear predictor; resulted in 283 matched pairs (n=566) with balanced covariates. Baseline comparisons: in unmatched cohort—Mann–Whitney U, Pearson’s χ2, Poisson regression; in matched cohort—Wilcoxon signed-rank, McNemar’s χ2, mixed-effects Poisson models as appropriate. Outcomes in matched cohort analyzed with maximum likelihood mixed-effects linear models accounting for matched-pair clustering. Subgroup analyses via full factorial interactions of pet ownership with subgroup variables, reporting subgroup-specific marginal effects. Atopy symptom changes analyzed by single-sample t-test vs null mean of 3 (no change). Nominal two-sided p<0.05 considered significant; authors note multiplicity and suggest Bonferroni-adjusted threshold ~0.002 under conservative assumptions, encouraging focus on effect sizes and CIs.

Cohort: 823 respondents (429 pet owners, 394 non-owners). After PSM, 283 owners matched to 283 non-owners (n=566) with balanced demographics. Physical activity (matched cohort overall): No significant differences between pet owners and non-owners in weekly minutes of mild (β=10.8, 95% CI −3.90 to 25.6; p=0.150), moderate (β=−0.6, 95% CI −7.30 to 6.10; p=0.866), or vigorous activity (β=−3.0, 95% CI −8.10 to 2.10; p=0.251). Physical activity subgroup effects: - Mild: Higher among owners with caregiver activities score ≥3 (β=56.8, 95% CI 21.1 to 92.4; p=0.002), caregiver hygiene score ≥3 (β=61.1, 95% CI 22.0 to 100; p=0.002), and household income ≥$10,000 (β=28.8, 95% CI 6.24 to 51.3; p=0.012). Lower among owners with caregiver healthcare score ≥3 (β=−30.1, 95% CI −58.7 to −1.54; p=0.039) and among cat owners (β=−29.1, 95% CI −57.8 to −0.443; p=0.047). - Moderate: Higher among main caregivers (β=14.1, 95% CI 2.79 to 25.3; p=0.015), dog owners (β=13.1, 95% CI 1.30 to 25.0; p=0.030), cat owners (β=36.7, 95% CI 6.60 to 66.8; p=0.017), bird owners (β=37.2, 95% CI 5.09 to 69.4; p=0.023), and across caregiving roles: feeding ≥3 (β=17.1, 95% CI 7.42 to 26.9; p=0.001), healthcare ≥3 (β=22.1, 95% CI 7.98 to 36.3; p=0.002), activities ≥3 (β=23.0, 95% CI 9.70 to 36.3; p=0.001), hygiene ≥3 (β=21.8, 95% CI 7.79 to 35.8; p=0.002). - Vigorous: Higher among main caregivers (β=19.0, 95% CI 4.70 to 33.3; p=0.009), caregiver feeding ≥3 (β=17.2, 95% CI 5.60 to 28.8; p=0.004), healthcare ≥3 (β=15.1, 95% CI 3.49 to 26.8; p=0.011), activities ≥3 (β=17.8, 95% CI 6.50 to 29.1; p=0.002), hygiene ≥3 (β=14.4, 95% CI 2.60 to 26.2; p=0.017), and dog ownership (β=20.5, 95% CI 3.50 to 37.6; p=0.018). SF-36 subscales (matched cohort overall): No differences in emotional well-being, social functioning, general health, or energy. SF-36 subgroup effects: - General health: Higher among Malay pet owners (β=10.4, 95% CI 0.270 to 20.5; p=0.044) and bird owners (β=6.7, 95% CI 0.550 to 12.9; p=0.033). - Emotional well-being: Higher among owners aged 41–50 (β=4.0, 95% CI 0.930 to 6.98; p=0.010) and 51–64 (β=5.8, 95% CI 1.25 to 10.3; p=0.012), single owners (β=3.8, 95% CI 0.529 to 6.98; p=0.023), main caregivers (β=2.7, 95% CI 0.100 to 5.32; p=0.042), and dog owners (β=3.5, 95% CI 0.340 to 6.72; p=0.030). - Energy: Higher among ages 31–40 (β=3.0, 95% CI 0.200 to 5.73; p=0.036), 41–50 (β=4.4, 95% CI 0.670 to 7.87; p=0.014), 51–64 (β=5.8, 95% CI 0.530 to 11.0; p=0.031), Malay race (β=12.0, 95% CI 1.48 to 22.4; p=0.025), and main caregivers (β=3.8, 95% CI 0.410 to 7.27; p=0.028). - Social functioning: Higher among ages 41–50 (β=4.6, 95% CI 1.01 to 8.18; p=0.012) and 51–60 (β=7.05, 95% CI 1.72 to 12.4; p=0.009). Effect modification by age: Continuous interaction analyses indicated pet ownership associated with higher emotional well-being, energy, and social functioning above ages 39 (p=0.043), 35 (p=0.044), and 39 (p=0.042), respectively, with increasing benefits at older ages; no significant age interaction for physical activity or general health. Atopy: In unmatched data, asthma diagnosis more prevalent among pet owners (19.1%) vs non-owners (14.0%), difference removed after matching. Among respondents with diagnosed atopy, current owners reported worsening allergic rhinitis after pet acquisition (mean 2.82, 95% CI 2.68–2.96; p=0.012 vs 3). After cessation of past pet ownership, past owners reported improvements in allergic rhinitis (mean 3.15, 95% CI 3.01–3.29; p=0.039) and eczema (mean 3.12, 95% CI 3.02–3.22; p=0.016); no significant changes for asthma in either comparison.

The study found no overall association between pet ownership and physical activity or SF-36 mental health-related subscales after balancing covariates via propensity score matching, but revealed heterogeneous effects within subgroups. Greater engagement with pets—particularly being the main caregiver and participating in caregiving tasks—was associated with higher moderate and vigorous physical activity, supporting the notion that benefits depend on active involvement (e.g., dog walking and pet-related activities). Dog ownership, more than other pet types, aligned with increased higher-intensity physical activity and better emotional well-being, possibly reflecting closer companionship and activity patterns unique to dogs. Mental health benefits appeared moderated by age: owners above their mid-30s to late-30s experienced higher emotional well-being, energy, and social functioning, suggesting cumulative or age-related accrual of benefits. Single pet owners and main caregivers also reported better emotional well-being, consistent with pets providing social/emotional support where human support may be lower. Some racial and pet-type differences (e.g., Malay race and bird ownership) were linked to better general health or energy but require cautious interpretation given multiplicity. For atopy, self-reported allergic rhinitis worsened upon pet acquisition among those with diagnosed disease and improved after pet ownership ceased (and eczema improved post-cessation), consistent with pets acting as allergen sources in susceptible individuals. However, these findings are limited by cross-sectional design, potential recall bias, and lack of granular temporal clinical data. Overall, findings suggest that health effects of pet ownership are context-dependent, influenced by age, caregiving engagement, and pet type. While propensity matching supports more credible comparisons than unadjusted analyses, results involving multiple subgroup tests should be interpreted emphasizing effect sizes and precision rather than nominal p values alone.

This first Southeast Asian study on pet ownership and health found no overall differences in physical activity or SF-36 mental health domains between pet owners and non-owners after propensity score matching. However, main pet caregivers exhibited higher moderate- and vigorous-intensity physical activity and reported higher emotional well-being and energy. Age modified associations with mental health, with benefits emerging and increasing above ages 35–39. Single owners experienced higher emotional well-being than single non-owners. Among individuals with atopy, allergic rhinitis worsened during pet ownership and both allergic rhinitis and eczema improved after pet ownership cessation. These findings add contextual nuance, indicating specific subgroups may experience beneficial or adverse outcomes linked to pet ownership, and motivate targeted interventions and prospective research, including longitudinal studies on atopy and evaluations of pet-assisted and pet-exposure programs for older adults and youth.

- Cross-sectional design limits causal inference and cannot disentangle effects from natural disease progression, especially for atopy. - Young, digitally-connected sample (nearly half aged 21–30) and exclusion of individuals ≥65 years reduce generalizability, particularly to older adults and those with more comorbidities. - Voluntary online recruitment may introduce selection bias; although PSM mitigates confounding, unmeasured confounding may remain. - Multiple testing across numerous subgroups raises Type I error risk; nominal p values reported without formal multiplicity adjustment (Bonferroni threshold ~0.002 suggested for conservative interpretation). - Potential recall bias in self-reported atopic symptom changes and limited temporal detail on onset relative to pet ownership. - Self-reported physical activity may be prone to measurement error; extreme values were excluded but residual misreporting is possible.