The Positive Effects of Pet Ownership on Alzheimer's Disease

Background: Human-animal interactions are known to have many beneficial psychosocial and psychophysiological effects on persons with and without medical health conditions. There are no previous prospective studies with long follow-up times on the effects of domestic pets on the persons with Alzheimer's disease (AD) living at home. Objective: To investigate the effects of pets on the activities of daily living (ADL), disease progression, and neuropsychiatric symptoms (NPS) during a five-year follow-up on the persons with AD. Methods: Altogether 223 home-dwelling persons (mean age 75.2 years) with very mild (CDR 0.5) or mild (CDR 1) AD at baseline were included for this study. ADCS-ADL, NPI, MMSE, and CDR-SOB were measured at baseline, annually for three years and after five years. Results: Totally 40 (17.9%) participants had a pet. At the baseline, pet owners and non-pet owners had no significant differences in age, gender, or the ADCS-ADL, NPS, and CDR-SOB scores, while MMSE was lower in pet owners than non-pet owners (20.2 versus 21.7; p = 0.009). Over the follow-up, pet owners had significantly better mean ADCS-ADL (57.5 versus 54.0; p = 0.031), NPI (9.3 versus 13.0; p = 0.038), and CDR-SOB scores (5.7 versus 6.6; p = 0.004) compared to non-pet owners. The differences in the MMSE scores between the groups detected at baseline attenuated over time. Conclusion: Significant positive effects of the pets on ADL functions, NPS, and disease progression were detected over the whole follow-up suggesting that having a pet may support daily activity and slow the disease progression in AD.