Pet ownership in the homeless population: do pets improve mental health status?

a Knowledge Summary by

Kimberly Conway DVM ^1*

¹UC Davis School of Veterinary Medicine, 944 Garrod Dr, Davis, CA 95616
^*Corresponding Author (kconway@ucdavis.edu)

Clinical scenario

You are a small animal veterinarian working at a busy clinic in downtown Sacramento, CA, USA. Your next appointment is a 3 year old female intact Pitbull scheduled for a rabies vaccine. You walk in the room to find a patient who is friendly, has a body condition score (BCS) of 4/9 and a dirty coat, but otherwise apparently healthy. Based on the owner’s appearance, you suspect both she and the dog are homeless. The owner only has enough funds for the rabies vaccine, which she needs in order to license her pet with the city to be able to move into a transitional housing unit. As you and your technician* exit the room to get the vaccine, your technician expresses concern for the welfare of the dog, and is considering calling Animal Control or even offering to help the owner rehome the dog. You consider how important this pet must be to this owner, and want to find some evidence to share with your technician that may change her perspective.

*A veterinary technician is the US equivalent of a veterinary nurse (UK).

The evidence

The 11 qualitative studies all reported are mostly anecdotal and opinion-based evidence regarding the benefits to mental health associated with pet ownership, and nearly all were lacking in sufficient sample size and statistical analysis, and had clear evidence of selection bias. Nevertheless, all of the papers reported near unanimous conclusions supporting the benefits that pets can have on a homeless individual’s mental health. These conclusions were also captured by the two scoping review studies.

The two cross-sectional studies provided stronger evidence as they incorporated more of a quantitative assessment (for example, standardised Center for Epidemiologic Studies – Depression (CES–D) scores or odds ratios). These studies also had more appropriate sample sizes and comparison groups. Thus, the conclusions from these two studies are more scientifically substantiated.

While the content of the studies supports the hypothesis, there is a strong need for more quantitative and longitudinal studies in this topic area.

Summary of the evidence

Appraisal, application and reflection

Homelessness is an increasing public health epidemic in the United States, and up to 25% of homeless individuals own pets (Rhoades et al., 2015). By understanding the potential mental health benefits that pets provide to these individuals, there is a potential to increase the amount of scientific information available to the general public, to potentially change negative perceptions associated with pet ownership in the homeless population.

While the conclusions made among the qualitative and qualitative/cross-sectional hybrid studies were near unanimous in their findings, that pets can improve the mental health status of homeless individuals (Yang et al., 2020; Labrecque & Walsh., 2011; Cleary et al., 2020; Howe & Easterbrook, 2018; Lem et al., 2013; Slatter et al., 2012; Kidd & Kidd, 1994; Rew, 2000; Brewbaker, 2012; Cleary et al., 2021; Scanlon et al., 2021; and Schmitz et al., 2021), these results should be interpreted with caution as there are multiple limitations and biases in these studies. Nine out of these 11 studies had small sample sizes ranging from 2–34 subjects, while the Kidd & Kidd (1994) and Labrecque & Walsh (2011) studies had a sample size of 105 and 51, respectively. Given the nature of qualitative studies, which generally do not report any statistical analysis, the small sample size is understandable given the degree of in-depth interviews conducted. However, the biases associated with these studies cannot be ignored; most notably the selection bias. Many of these studies focused solely on pet owners, with targeted questions regarding the effects their pet has had on them. Few studies asked similar questions to non-pet owners, so the generalisability of these results is limited. Additionally, with the exception of Kidd & Kidd (1994), all of these studies selected participants by recruiting at shelters, day clinics, free street veterinary clinics, or similar scenarios. This creates a significant selection bias towards individuals who have access to these facilities, who feel safe and welcome at them, and who knew they could bring their pet. This leaves a potentially large proportion of homeless individuals who are unreachable – whether they were not qualified to access clinics (if guests are required to have a drug test before coming, for example), or perhaps they did not think their pet would be allowed. Thus, the population of people who were already in a position to come to these clinics may already have better circumstances and thus, improved mental health compared to those who are even more marginalised. With all limitations and biases considered, there is still an effect to be noted that those who were included in the study, albeit part of a small sample size or fairly unavoidably biased population, all reported various ways their pets improved their own perception of their mental health.

Unlike the qualitative studies, the two cross-sectional studies provided more quantitative and statistically significant results with a larger sample size and a comparison group. The study performed by Lem et al. (2016) is the only study to perform a quantitative measure of effect (odds ratio) using prevalence to show the odds of depression in pet owners is three times lower compared to non-pet owners. Similarly, Rhoades et al. (2015) was able to perform a chi-square quantitative analysis showing that homeless pet owners’ scores on a depression and loneliness scale were significantly lower than non-pet owning homeless individuals. Despite the strength behind these quantitative studies compared to the qualitative studies, these studies were also limited in the same selection bias that results from only selecting participants who had access to shelter services. Additionally, these cross-sectional studies can only conclude there is an association between pet owners and depression, without any means of determining causality. As such, it is possible that individuals who are in a better mental health state are more likely to be a pet owner.

Based on the literature described above, it is evident there is a clear need for more quantitative and longitudinal studies in this area. However, the feasibility of performing a cohort study in this population would be very challenging. Many individuals experiencing homelessness would be likely lost to follow-up, or potentially become temporarily housed which would complicate their role in the study. Additionally, the selective bias in all of these studies indicates a need to access a proportion of the homeless population that does not have access to shelters, but attempts to reach this population may be complicated by an increased chance of encountering individuals whose ability to consent to participate may be influenced by other factors. Additionally, as Schmitz et al. (2021) pointed out, some questions may be framed to encourage a positive response regarding pet ownership, leading respondents to only report the positive mental effects associated with pet ownership.

Overall, there is a clear need to continue research in this area, as homelessness continues to increase nationwide. While the evidence does support the conclusion that there is an increase in the mental health status associated with pet ownership in this population, many individuals reported grief and stress associated with the loss of a pet. Future efforts should attempt to address these potential negative impacts to mental health as well. Thus, further research should be focused on the potential decrease in mental health associated with pet loss that many of these studies highlighted, and the long-term consequences associated with that loss.

Methodology Section

Search Strategy
Databases searched and dates covered:	CAB Abstracts accessed via the CAB Direct platform (1973­–2021) PubMed accessed via the NCBI platform (1920-August 2021 week 34) Scopus accessed via the Elsevier platform (1994–2021) Google scholar (select articles hand-picked via specific search)
Search strategy:	CAB Abstracts: ((dog* or pet* or cats*) AND (homeless* or "homeless people") AND (benefit* or emotion* or mental* or depress*))   PubMed: (Pet or “pet owner”) and homeless*   Scopus: ALL(“pet owner” AND homeless*) AND (benefit* OR emotion* OR depress* OR mental)   Google scholar: Hand-picked three relevant articles found through references of other included articles – searched directly by author and title
Dates searches performed:	9 Aug 2021

Exclusion / Inclusion Criteria
Exclusion:	Not in English, did not jointly include homeless pet owners and/or did not evaluate any aspect of mental health.
Inclusion:	In English, jointly evaluated homeless pet owners and directly evaluated any factor relating to mental health.

Search Outcome
Database	Number of results	Excluded – Did not jointly evaluate mental health and pet ownership	Excluded – Duplicate/already included from previous search	Excluded – Purely narrative with minimal to no outcomes evaluated	Total relevant papers
CAB Abstracts	28	25	0	0	3
PubMed	10	9	0	0	1
Scopus	100	86	4	1	8
Google Scholar (select articles)	3	0	0	0	3
Total relevant papers when duplicates removed					15

The author, Dr. Kimberly Conway, has co-led efforts to establish a new veterinary clinic offering free veterinary services for pet owners experiencing homelessness in Davis, CA (Davis Pet Advocacy and Wellness Clinic).

1. Brewbaker, E.J. (2012). The experience of homelessness and the human-companion animal bond : a quantitative study : a project based upon an investigation at San Francisco Community Clinic Consortium/Veterinary Street Outreach Services, San Francisco, California. Theses, Dissertations,and Projects. Smith College, Northampton, MA. [online] Available from: https://scholarworks.smith.edu/theses/869 [Accessed 1 Dec 2020]
2. Cleary, M., Visentin, D., Thapa, D.K., West, S., Raeburn, T. & Kornhaber, R. (2020). The homeless and their animal companions: an integrative review. Administration and Policy in Mental Health and Mental Health Services Research. 47(1), 47–59. DOI: https://doi.org/10.1007/s10488-019-00967-6
3. Cleary, M., West, S., Visentin, D., Phipps, M., Westman, M., Vesk, K. & Kornhaber, R. (2021). The Unbreakable Bond: The Mental Health Benefits and Challenges of Pet Ownership for People Experiencing Homelessness. Issues in Mental Health Nursing. 42(8), 741–746. DOI: https://doi.org/10.1080/01612840.2020.1843096
4. Howe, L. & Easterbrook, M. J. (2018). The perceived costs and benefits of pet ownership for homeless people in the UK: practical costs, psychological benefits and vulnerability. Journal of Poverty. 22(6), 486–499. DOI: https://doi.org/10.1080/10875549.2018.1460741
5. Hughes, M.E., Waite, L.J., Hawkley, L.C. & Cacioppo, J.T. (2004). A Short Scale for Measuring Loneliness in Large Surveys: Results From Two Population-Based Studies. Research on Aging. 26(6), 655–672. DOI: https://doi.org/10.1177%2F0164027504268574
6. Kerman, N., Gran-Ruaz, S. & Lem, M. (2019). Pet ownership and homelessness: a scoping review. Journal of Social Distress and the Homeless. 28(2), 106–114. DOI: https://doi.org/10.1080/10530789.2019.1650325
7. Kidd, A.H. & Kidd, R.M. (1994). Benefits and Liabilities of Pets for the Homeless. Psychological Reports. 74(3), 715–722. DOI: https://doi.org/10.2466/pr0.1994.74.3.715
8. Johnson, T. P., Garrity, T. F. & Stallones, L. (1992). Psychometric Evaluation of the Lexington Attachment to Pets Scale (Laps). Anthrozoös. 5(3), 160–175. DOI: https://doi.org/10.2752/089279392787011395
9. Labrecque, J. & Walsh, C.A. (2011). Homeless Women’s Voices on Incorporating Companion Animals into Shelter Services. Anthrozoös. 24(1), 79–95. DOI: https://doi.org/10.2752/175303711X12923300467447
10. Lem, M., Coe, J.B., Haley, D.B., Stone, E. & O’Grady, W. (2013). Effects of Companion Animal Ownership among Canadian Street-involved Youth: A Qualitative Analysis. Journal of Sociology and Social Welfare. 40(4), 285–304. [online] Available from: https://scholarworks.wmich.edu/jssw/vol40/iss4/15?utm_source=scholarworks.wmich.edu%2Fjssw%2Fvol40%2Fiss4%2F15&utm_medium=PDF&utm_campaign=PDFCoverPages [Accessed 1 Dec 2020]
11. Lem, M., Coe, J.B., Haley, D.B., Stone, E. & O’Grady, W. (2016). The Protective Association between Pet Ownership and Depression among Street-involved Youth: A Cross-sectional Study. Anthrozoös. 29(1), 123–136. DOI: https://doi.org/10.1080/08927936.2015.1082772
12. Rew, L. (2000). Friends and Pets as Companions: Strategies for Coping With Loneliness Among Homeless Youth. Journal of Child and Adolescent Psychiatric Nursing. 13(3), 125–132. DOI: https://doi.org/10.1111/j.1744-6171.2000.tb00089.x
13. Rhoades, H., Winetrobe, H. & Rice, E. (2015). Pet Ownership Among Homeless Youth: Associations with Mental Health, Service Utilization and Housing Status. Child Psychiatry & Human Development. 46, 237–244. DOI: https://doi.org/10.1007/s10578-014-0463-5
14. Scanlon, L., Hobson-West, P., Cobb, K., McBride, A. & Stavisky, J. (2021). Homeless People and Their Dogs: Exploring the Nature and Impact of the Human–Companion Animal Bond. Anthrozoös. 34(1), 77–92. DOI: https://doi.org/10.1080/08927936.2021.1878683
15. Schmitz, R.M., Carlisle, Z.T. & Tabler, J. (2021). “Companion, friend, four-legged fluff ball”: The power of pets in the lives of LGBTQ+ young people experiencing homelessness. Sexualities. DOI: https://doi.org/10.1177/1363460720986908
16. Slatter, J., Lloyd, C. & King, R. (2012). Homelessness and Companion Animals: More than Just a Pet? British Journal of Occupational Therapy. 75(8), 377-83. DOI: https://doi.org/10.4276%2F030802212X13433105374350
17. Yang, H., Howarth, A., Hansen, S.R., Harrell, L. & Thatcher, C.D. (2020). Understanding the Attachment Dimension of Human-animal Bond within A Homeless Population: A One-Health Initiative in the Student Health Outreach for Wellness (SHOW) Clinic. Journal of Applied Animal Welfare Science. 24(4), 357–371. DOI: https://doi.org/10.1080/10888705.2020.1801434