A Scoping Review of the Risks Posed by Companion Animals to Older Adults

ABSTRACT

Research has reported on positive aspects of pet guardianship to reduce physical and mental health issues in older adults (over the age of 65 years). There is, however, a need to be cognizant of the risks that pertain to companion animal guardianship. The aim of this scoping review was to systematically identify literature regarding the risks that companion animal guardianship may pose to older adults to facilitate greater understanding and inclusion of pets in the lives of older adults. Using online databases (Scopus, ProQuest, and Google Scholar), systematic searches were conducted. From 11,868 articles, 26 were included in the final data synthesis. The type of risk reported was categorized into three groups (zoonotic, physical, and psychological), with the worst outcomes reported being fatal, potentially fatal, and severe, respectively. Very little literature for pet species other than dogs and cats were identified. Whilst further research is required to fully quantify the risks that arise from the cohabitation of pets and older adults, there is enough evidence for older adults to be safely engaging with pets and hence continue to benefit from the human–animal bond.

KEYWORDS:

• Aged
• companion animals
• human–animal interaction
• older adults
• pet guardianship
• risk

Older adults (aged over 65 years) are at an increased risk for multiple physical and mental health issues. Osteoarthritis, pain, hearing/vision loss, and chronic obstructive pulmonary disease are common physical conditions in older adults (WHO, 2022), while depression and anxiety are some of the most common mental health issues (Kiely et al., 2019). Aged care residents are at particular risk of depression, with over 50% of them exhibiting symptoms compared with 15% of older adults living in the community (AIHW, 2013). More alarmingly, there are reports of one in six aged care residents engaging in self-destructive behavior at least once a week, and suicide rates of the general population are the highest in adults over 65 years (Conejero et al., 2018; Draper et al., 2002).

To combat these physical and mental health issues, the human–animal bond in older adults has been described as not only life enhancing but even lifesaving (Obradović et al., 2021; Young et al., 2020). Multiple positive physical health outcomes associated with human–animal interactions have been observed in the cardiovascular field, and whilst the research has not focused on older adults, there have been many positive associations found, including lower blood pressure and heart rate in the presence of pets (Allen et al., 2002; Friedmann et al., 2011). Research into the role of animals in the mitigation of mental health disorders, including depression and anxiety, has also yielded promising results. Souter and Miller’s (2007) meta-analysis on the effectiveness of animal-assisted activities (AAAs) to help treat depression in people, whilst not specific to older adults, found that they are associated with fewer depressive symptoms. In addition to this, research into animal-assisted therapy for older adults with dementia (Travers et al., 2013), Alzheimer’s disease (Mossello et al., 2011), and those that require the use of a wheelchair/walker (Le Roux & Kemp, 2009) found a reduction in anxiety and depressive symptoms.

Contrasting with the observed positive effects of pets on older adults, companion animals may still pose risks to guardians’ physical and mental wellbeing. Falls due to pets acting as tripping hazards and other physical injuries, such as bites and scratches, are a major health concern in older adults as the common physical impairments listed above may amplify the risk or outcome severity of these incidents (Kurrle et al., 2004). Pet contact also poses a risk for over 70 zoonotic infections (Stull et al., 2015), of which adults over 65 years are classified as being at high risk (Said et al., 2023). There are also some documented mental health risks related to pets, including self-neglect, hoarding, and grief (Hoarding of Animals Research Consortium (HARC), 2002; Scheibeck et al., 2011).

With the positive aspects of pet guardianship for older adults being observed and encouraged, there is a need to be cognizant of the risks and cautions that pertain to them. This is so that it is possible to proactively prevent or reduce negative impacts on both people and animals, particularly in the context of potentially frail older individuals. A critique of the human–animal relationship field in general, including that focused on older adults, is that it has a positive bias, with mainly positive outcomes and findings being researched and published (Gee et al., 2017). Typically, the risks associated with pet animals and their impact on older adults, including mitigation, are either briefly mentioned or completely disregarded in the current literature (Casey et al., 2018; Friedmann et al., 2015; Needell & Mehta-Naik, 2016). Consequently, there exists a significant knowledge gap regarding the potential risks companion animals may pose to older adults.

This paper presents the results of a scoping review on the risks that pets may pose to older adults, defined here as those over the age of 65 years. The results of this review can facilitate greater understanding and inclusion of pets in the lives of older people, for systematically identifying risks means it is possible to address them directly and reduce both their occurrence and impact. In addition, any identified research gaps can be further researched.

Methods

We chose to implement a scoping review owing to the format’s aptness for both mapping literature with numerous methodological approaches and applying a broader research question. The method and framework for scoping reviews set out by Arksey and O’Malley (2005) was used. No ethical approval was required for this review.

Inclusion and Exclusions Criteria

Inclusion and exclusion criteria for the literature search were defined by using the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines (Page et al., 2021). The inclusion criteria were: (1) primary sources written in English, (2) published after 1995 and up to the search date of October 1, 2022, (3) the source was focused on older adults and companion animal interactions or had information that could be applicable to all ages. Companion animals included cats, dogs, fish, birds, reptiles, amphibians, and small mammals, including assistance and therapy animals. These taxa and species were chosen owing to their prevalence as pets/companion animals (Animal Medicines Australia, 2021; GfK, 2016). The cut-off date of 1995 was used in order to limit the search returns in included databases. Any setting (e.g., aged care facility (ACF) or community) was included. Exclusions were articles that measured risks to animals but not to humans and those mentioning basic risk mitigation techniques but not specific risks.

Search Strategy

The search was carried out on the online databases of Scopus (https://www.scopus.com) and ProQuest (https://www.proquest.com). The decision to use these databases was because of their relevance to anthrozoology and the availability of significant literature (Elsevier, 2023). Google Scholar (GS) (https://scholar.google.co.au/) was later added in order to increase sensitivity for non-peer-reviewed articles.

The search strategy for both Scopus and ProQuest involved the use of three groups of keywords and then a set of exclusions to narrow the search. The first keywords related to older adults, such as “older adults,” “aged care,” “elderly,” and “nursing home.” The second group of keywords related to companion animals, such as “pets,” “animals,” “dogs,” “cats,” and “birds.” The final group of keywords related to risks and hazards (see online supplemental file for full search strategy). This search was restricted to the title, abstract, keyword, and then a large group of “NOT” terms were added to limit the returned results. A simplified search strategy was used for Google Scholar (see online supplemental file), with reports sorted by relevance and then the first 300 reports were screened.

Data Extraction

JZ developed the data extraction table, which was then reviewed by TDN. Data extraction was completed through Covidence Systematic Review Software (2022) and included title, author, country, study design/setting, pet species, specific risk addressed, and relevant outcomes/key findings. JZ and TDN reviewed the final articles before JZ extracted the data.

Results

In total, 11,868 sources reporting on risks of companion animals to older adults were identified (Figure 1). After removing duplicates, the dataset contained 1,347 articles. These were then filtered by reading the title and abstract, narrowing the search to 127 sources. Then, after assessing the full articles, 26 sources remained.

Figure 1. PRISMA flow diagram: Process used in identification and screening of sources (n = 11,868). *Unsuitable outcomes included no primary research achieved, basic risk mitigation techniques discussed but not specific risks, risks to animals discussed but not to humans.

Research was undertaken in a variety of settings (community, hospitals, and residential ACFs) and discussed the intersections of older adult lives and pet animals across these (noting that people do not live in hospital but may enter and then transition from this location). As summarized in Table 1, across the extracted (26) articles, there were 24 that identified the species of animals; however, almost one-third of the sources just talked about pet animals in a generic manner. Dogs were the most species mentioned (including two sources referencing therapy dogs), followed by cats, while none of the papers referred to other mammals or fish.

Table 1. Pet species identified in the 26 included sources.^a

Pet species	Number of sources
Dog^b	13
Cat	10
Reptiles	1
Birds	1
Not specified (general pets)	8

^a Some sources included more than one species/group.

^b Two sources were therapy dogs.

Risk Categorization

The type of risk reported was categorized into three groups: zoonotic, physical, and psychological. The number of sources addressing each of the three categories, with three major sub-categories for each, are summarized in Table 2. Sources were categorized according to their major focus, although they might briefly mention other categories. Zoonotic and physical and risks were evenly documented throughout the study period, with psychological risks being identified more predominately in recent years (2010 onwards). Article authors also commonly either made observations (e.g., death) or judgements as to the severity of the outcome of pet risks, as noted in Table 2. Bacterial infections caused by zoonotic transmission were identified as fatal, and all physical risks were potentially fatal, while the severity of the risk of stress related to a pet going missing was identified only as “low.”

Table 2. The types of risk, the number of sources that identified them, and their outcome severity.

Risk	Number of sources	Identified outcome severity
Zoonotic
Bacterial zoonoses	9	Fatal
Protozoal zoonoses	1	Not specified
Chlamydial zoonoses	1	Not specified
Total	11
Physical
Fall	6	Potentially fatal
Bite/scratch	2	Potentially fatal
General Injury	1	Potentially fatal
Total	9
Psychological
Grief due to death of a pet	4	Potentially severe
Self-neglect	1	Potentially severe
Stress due to pet going missing	1	Low
Total	6

Zoonotic Risks

Table 3 provides details on 11 sources that identified zoonotic risks. The majority (9/11) focused on one particular disease and past outbreaks that have occurred. The severity of outcome differed depending on the type of zoonosis, as did the extent of any potential outbreaks. Nine separate species of bacteria were identified, with Campylobacter jejuni being the only species that caused a death due to an outbreak. Hospitalization occurred from six separate bacterial infections. Dogs and cats were the host species for all diseases, except for Salmonella paratyphi and Chlamydophila psittaci, which were contracted from turtles and birds, respectively.

Table 3. Details on 11 sources that identified zoonotic risks.

Specific risk	Species	Country	Study design and setting	Outcome/conclusions	Reference
Campylobacter jejuni	Dog (4-month-old puppy)	Australia	Case study, 2 outbreaks of gastroenteritis. ACF.	13 cases, 1 death, and 1 hospitalization.	Moffat et al. (2014)
Chlamydophila psittaci (formerly known as Chlamydia psittaci)	Birds	Egypt	Cross-sectional study to determine the prevalence and potential risk factors associated with C. psittaci infections in psittacine birds and bird handlers in Egypt. Community.	Prevalence of C. psittaci infections in handlers was 4/70 (6%). 11.4% of handlers had flu-like symptoms.	Tolba et al. (2019)
Intestinal protozoa	Not specified (general pets)	Brazil	Cross-sectional study to determine the prevalence of intestinal protozoa in ACFs. ACF.	From the total samples taken from older adults, 28 (9.5%) tested positive for intestinal protozoa (Giardia duodenalis, Cryptosporidium spp., Entamoeba coli, Endolimax nana., Entamoeba histolytica/dispar). Outcome not stated.	Girotto et al. (2013)
Pasteurella multocida	Cats	Japan	Case study. Community.	71-year-old woman, chronic illness (cough, sputum, dyspnea, and left pulmonary infiltration). Referred for investigation, 14 days antibiotic treatment.	Itoh and Kurai (2018)
	Cats	USA	Case study. Community.	70-year-old woman Hospitalized for 14 days.	Ferreira et al. (2015)
	6 cats and a dog	Greece	Case study. Community.	87-year-old male, high fever, purulent productive cough. Hospitalized.	Kofteridis et al. (2009)
Salmonella paratyphi B	Turtles	USA	Case report on a multistate human salmonella outbreak. Community.	103 cases from 33 states, (age range: < 1–87 years), 56% were aged < 10 years. 65% reported bloody diarrhea, with a median duration of illness of 7 days; 30% were hospitalized for their illnesses, with a median duration of 4 days. 59% reported turtle exposure during the 7 days before illness onset. No deaths reported.	CDC (2008)
Salmonella thompson	Dog	USA & Canada	Case report on how contact with salmonella-contaminated pet treats of beef and seafood origin resulted in nine culture-confirmed human S. thompson infections. Community.	Two patients (aged 26 and 37 years) sought medical care due to diarrheal illness, one 81-year-old patient was hospitalized due to diarrheal illness, fever, and vomiting. Six additional cases were confirmed with no outcome stated.	CDC (2006)
Salmonella typhimurium	Dogs and Cats	USA	Case study on an outbreak of S. typhimurium. Community (vet clinic).	Confirmed cases in two veterinary technicians, four persons associated with clinic patients, and a nurse not linked to the clinic. Symptoms of the infection included diarrhea, cramps, fever, and nausea. The median duration of illness was 8 days.	Cherry et al. (2004)
Methicillin-resistant Staphylococcus aureus (MRSA)	5 dogs and 3 cats	US & Canada	Prospective cohort and nested case-control studies. Community (household or veterinary facility).	An MRSA isolate was recovered from at least one human that was in contact with each animal case. Outcome not stated.	Weese et al. (2006)
Multidrug-resistant (MDR) Staphylococci spp. (Staphylococci with mecA and MRSA)	Not specified (general pets)	Switzerland	A retrospective study of the carriage of MDRS in two groups of ACF residents: those living in nursing homes with pets vs. without pets. ACF.	MDR staphylococci carriage identified. A total of 815 staphylococcal strains were isolated from the nostrils of the residents. Outcome not stated.	Gandolfi-Decristophoris et al. (2012)

Note: ACF, aged care facility.

Physical Risks

The second most reported risk (9 reports) was the physical risk companion animals may pose to older adults. Table 4 details these reports. Falls were the most prevalent physical risk (6 separate sources), from single-case studies to reports estimating 86,000 falls/year in the US. Dogs and cats were identified as the cause of falls in sources that identified a specific species. Falls in older adults were seen to be potentially fatal due to complications from hip fractures. Older adults were also significantly more likely to be hospitalized from a dog or cat bite/scratch when compared with other age groups.

Table 4. Details on nine sources that identified physical risks.

Specific risk	Species	Country	Study design and setting	Outcome/conclusions	Reference
Bites/scratches	Dogs and cats	Italy	A retrospective case series on a patient admitted to the emergency department for bite or scratch injuries caused by dogs, cats, or other mammals (specific species not stated) between 1 January, 2000 and 31 December, 2002. Community.	The average yearly incidence of dog and cat bite/scratches was 58.4 and 17.9 cases per 100,000 residents, respectively. Dogs accounted for 76.9% and cats for 19.7% of cases. Injuries from cats were significantly more common in older people.	Ostanello et al. (2005)
	Dog	Australia	A case series of 356 victims of dog attacks who presented to the emergency department and 3,093 respondents to the 1992 South Australian Health Omnibus Survey. Community.	About 6,500 people injured in Adelaide each year as a result of dog attacks, with about 810 annual hospital treatments (7.3 per 10,000 people per year). Men aged over 76 years were attacked and required hospital treatment twice as often as men aged 36–75 years. Hospital admission rates were five times higher for older people.	Thompson (1997)
Injuries	Not specified (general pets)	Hong Kong	A cross-sectional telephone survey. Community.	84 of the 6,570 participants experienced a pet-related household injury in the past 12 months. Injury to the hands was the most common at 79.7%. No outcome reported.	Chan et al. (2017)
Trip/falls	Dog	USA	A retrospective, cross-sectional study into fracture risk in older adults who use leashes when walking dogs. Community.	32,624 cases of fall-related fractures associated with walking leashed dogs in older people, with hip fractures being the most common fracture.	Pirruccio et al. (2019)
	Not specified (general pets)	Brazil	A cross-sectional study of 350 community-dwelling adults > 80 years old. Community.	Participants were 2.1 times more likely to suffer a fall if owning a pet.	Pereira et al. (2017)
	Dogs and cats	USA	Retrospective case series of emergency department visits from 1 January, 2001 to 31 December, 2006. Community.	Based on 7,456 cases, an estimated 86,629 fall injuries each year were associated with cats and dogs. There were 7.5 times as many injuries involving dogs as cats. Injury rates were highest among people aged ≥75 years. Fractures and contusions or abrasions were the most common injuries; the highest rates were for injuries to the extremities. About 66.4% of falls associated with cats and 31.3% of falls associated with dogs were caused by falling or tripping over the pet. An additional 21.2% of falls related to dogs were caused by being pushed or pulled.	Stevens et al. (2010)
	Not specified (general pets)	Australia	Retrospective case series of pet-related falls in over 75-year-olds at a hospital between 1 April, 2003 and 30 September, 2004. Community.	16 cases of patients presenting to the emergency department with a fracture directly related to their pet.	Kurrle et al. (2004)
	Cat	Australia	A letter to the editor, declaring the case of an 81-year-old woman tripping over her cat and being admitted to hospital. Community.	The fall led to a 12-day hospital stay, with loss of previous mobility even on discharge.	Nair and Flynn (2004)
	Cats and dogs	Australia	A cross-sectional study of 257 in homes of community dwelling > 65-year-olds. Community.	Pets are identified as a hazard of 28% of participants. No outcome stated.	Clemson et al. (1997)

Psychological Risks

Grief due to the death of a pet was the most documented psychological risk. It was identified in over half the identified sources (4/6), with all describing the profound impact that the death of a companion animal can have on guardians (Table 5). The grief caused by the death of a companion animal can be so profound that it is comparable to the loss of a family member, can increase depressive symptoms, and may require professional help to process and overcome.

Table 5. Details on five sources that identified psychological risks.

Specific risk	Species	Country	Study design and setting	Outcome/conclusions	Reference
Grief due to death of a pet	Dogs and cats	Canada	Cross-sectional study, involving qualitative measurements – Pet Attachment and Life-Impact Questionnaire and the Pet Bereavement Questionnaire followed by qualitative interviews. Community.	Loss of a pet for all participants led to significant grief, with high-level grief continuing for over a year for numerous participants.	Wilson et al. (2021)
	Not specified (general pets)	Hong Kong	Longitudinal quantitative study in which depressive symptoms were assessed using Geriatric Depression Scale (GDS) in 2,630 community-dwelling people aged 65 years or above. Community.	Loss of a pet was associated with an increase in depressive symptoms among men.	Chan et al. (2012)
	Dogs	Austria	A qualitative study investigating the human–animal relationship from a gerontological perspective using ethnographic field research. Community.	Results showed that grief from pet loss was comparable to losing a dear friend or relative.	Scheibeck et al. (2011)
	Not specified (general pets)	Global	Chapter 25 from “Handbook on animal-assisted therapy,” entitled “Loss of a therapy animal: Assessment and healing.” ACF & Community.	Grief from the loss of a pet can be so profound that it requires a pet loss expert to help the bereaved through their loss.	Cohen (2010)^a
Self-neglect	Not specified (general pets)	Canada	71 retrospective case reports gathered from professionals dealing with hoarding. Community.	The majority of older animal hoarders satisfied criteria for self-neglect. 17% of homes were condemned or deemed unfit for human habitation, with 25% placed in permanent or temporary protective care.	Hoarding of Animals Research Consortium (HARC) (2002)
Stress from a pet going missing	Dog	Australia	A cross-sectional quantitative questionnaire assessing both concern for a missing therapy dog and attitude toward animal-assisted therapy programs. ACF.	The missing therapy dog caused concern to both residents and staff members, along with relief upon her return.	Crowley-Robinson and Blackshaw (1998)^a

^a Involved a therapy animal. ACF, aged care facility.

Discussion

Across 26 separate sources, this review identified risks related to the keeping of pets by older adults. The risks identified were grouped into three broad categories: zoonotic, physical, and psychological.

It is important to note the diversity of study settings in the identified literature as the findings may or may not be applicable to one another. Seven sources were completed in an ACF; hence, certain aspects may not be relevant for community-dwelling older adults. The inclusion of ACF-based studies in this review is important. Older adults who currently have or desire a pet fear moving to an ACF. They may not be allowed to keep an animal they currently have or be able to acquire one, especially if they need a higher level of care (Bridgman, 2014).

Zoonoses

A major issue found is the risk posed by pets to transfer diseases to people that they interact with. This review highlights the potential severity of zoonoses in older adults, with hospitalization an outcome in multiple incidences of disease outbreak (Ferreira et al., 2015; Kofteridis et al., 2009), and death occurring due to an outbreak of campylobacter at an ACF (Moffat et al., 2014). The literature identifies older adults as one of the most vulnerable cohorts in regard to zoonoses, along with the immunocompromised and people with chronic illnesses (O’Neil, 2018). Studies have shown that, in comparison with younger cohorts, older adults have progressive declines in total lymphocyte percentage and a lower number of absolute T and B cells, which are thought to be associated with a decline in the immune system of older adults (Valiathan et al., 2016).

Whilst potentially the most devastating for older adults, zoonotic diseases are one of the risk factors that can be effectively controlled in communal resident settings like ACFs. This is owing to mandatory requirements of infection control in these places, as well as having trained staff and protocols (National Health and Medical Research Council, 2019; Safe Animals Friendly Environments [SAFE], 2022). Required infection control procedures in residential communal aged care settings provide a strong foundation for protecting against zoonotic infections. Procedures and processes implemented to reduce human to human infection also protect from animal to human and human to animal disease transmission (Macpherson et al., 2022). However, facility and staff knowledge of pets and their role in infections is also important, including those related to specific species. This is highlighted in Moffat et al.’s (2014) investigation into an outbreak of Campylobacter spp. gastroenteritis in an Australian ACF. Whilst the facilities’ infection control strategies were labeled “adequate,” their animal policy failed to recognize the zoonotic risk posed by a puppy, which ultimately led to the death of a resident. For older adults living independently in the community, proper hygiene practices should be sufficient to minimize the risk of zoonoses (Friedmann et al., 2011). Prevention is always better than cure as outbreaks can lead to severe outcomes, hospitalization, and even death (Moffat et al., 2014).

Physical Risks

The physical risks of dogs and cats around older adults are relatively well documented, appearing in nine separate sources identified in this review. Of these, the most common risk was falls, which pose a major risk to older adults as they tend to have decreased bone density (Wright et al., 2014) and therefore the potential to incur severe trauma injuries (Pirruccio et al., 2019). The potential for pet animals to be tripping hazards is one that merits addressing in older adults. Proper leash training of pet dogs is one way to mitigate the fall risk related to walking a dog on a lead (Coates, 2019). Another way to mitigate this risk, which may be highly applicable if guardians are fairly inactive, is an alternate form of exercise for the dogs rather than leashed walking. This may involve at-home environmental enrichment or supervised play sessions in a park or large space (Hunt et al., 2022). There are also other options to provide assistance for older pet guardians, such as providing specific pension or government financial support for pets or local council projects which offer services such as walking older people's dogs by volunteers (e.g., Charles Sturt Council, n.d.).

Dog and cat bites/scratches are a risk to all pet guardians, not just older adults. However, with often fragile skin leading to greater physical trauma and/or the potential to be immunocompromised leading to secondary infections (Caserza et al., 2017; Hurt & Maday, 2018), a dog or cat bite to an older adult can be very serious, potentially leading to hospitalization (Ostanello et al., 2005; Thompson, 1997). The underlying principles of dog/cat-bite prevention and management for older adults do not seem to differ from those for the general population, with awareness and education key in this aspect (American Veterinary Medical Association, 2001).

The identified sources in this review did not discriminate between whether the animals involved were victims’ personal pets, were resident in a communal setting, or someone else’s pet. In addition, no physical risks from species other than dogs and cats were identified. These gaps in the literature highlight where further research is required.

Psychological Risks

The main identified psychological risk of pet guardianship was the grief that can come after the death of a pet (Chan et al., 2012; Cohen, 2010; Scheibeck et al., 2011; Wilson et al., 2021). Grief from pet loss can be comparable to that of losing a family member or close friend, and for some older adults who may be experiencing a reduced circle of friends, this loss can worsen problems such as depression and even lead to cognitive problems (Chu & Fong, 2022; Chur-Hansen, 2010; Clements et al., 2003). Whilst our knowledge of the benefits of pets to the mental state of older adults is a rapidly expanding area (Obradović et al., 2021; Young et al., 2020), the psychological risks are much less well documented for pet guardianship and animal-assisted therapies. The potential for pet death is one that is shared by all pet guardians and is difficult to individualize to older adults (Chur-Hansen, 2010).

The grief experienced can require expert help to guide guardians through the acute period, whether the loss is through death/euthanasia (Scheibeck et al., 2011) or an older guardian having to leave their pet due to moving to an ACF (Bridgman, 2014). Similar grief would be felt if a pet was stolen or went missing (e.g., strayed from home) (Robinson, 1995), although this was not identified in this review. Training those working with the aged in residential or community settings on how to identify and respond to grief following companion animal loss may be of benefit in mitigating potential long-term psychological issues. The positive effects of companion animals on geriatric depression, dementia, and loneliness are documented in the literature (Needell & Mehta-Naik, 2016; Olsen et al., 2016; Stanley et al., 2014), the risks, however, are much less studied. There is a need to develop strategies that address the negatives of pet guardianship so that the many positive impacts can continue to be part of older adults’ (and their pets’) lives.

Future Directions

Much of the current literature focuses on the benefits that animals can provide in the lives of older people. Very few sources include the risks of companion animals in their objectives; they are only lightly touched on or, more commonly, simply ignored. There is a need to bridge the research gap between the benefits and the risks of pet guardianship so that the benefits of human–animal relationships can be felt as long as possible in the lives of people for whom these are life-giving and enhancing (Young et al., 2020). Work that seeks to combine risk examination with protective, preventative, and mitigation understandings that can be readily applied in real life is needed. For example, there may be clear physical risk involved in a 16-year-old cat weaving around the legs of her frail guardian who has had her since a kitten. Yet, if the guardian sees the cat as her closest friend, especially since the loss of her human life partner, the knowledge we have on grief after pet loss indicates that there is a need for strategies that can maintain this relationship whilst reducing physical risks.

If there is a desire to ensure that pets are able to continue to live with their aged guardians even when guardians need to move into residential aged care, the risks must first be systematically identified. Infection control coupled with the proper vaccinating and worming of pets allows the risk of zoonotic disease to be relatively low (Friedmann & Son, 2009). Alternately, physical risks posed to older adults by pets may generally need to be managed on an individual and species-specific basis because the risks differ. Consistent use of a risk management framework and mitigation tool to enable more pets to live in community housing and ACFs (SAFE, 2022) can support the safe continuation of human–animal relationships into frail aging.

Much of the literature reviewed focused on dogs and to a lesser extent cats. This review only identified two reports that specifically identified risks related to other species (Centers for Disease Control and Prevention [CDC], 2008; Tolba et al., 2019). This fits with the broader picture of companion animal research, with little to no research on pet birds, fish, and other small animals. Pets such as birds can form extremely strong relationships with their guardians, and the grief felt at severing this bond can be just as severe as that after the loss of a cat or a dog (Anderson, 2003). Ko et al.’s (2016) study into pet insects found simply caring for five crickets in a cage for eight weeks, which required minimal physical effort for the older adult guardians and was an inexpensive process, still achieved small to medium positive effects on depression and cognitive function in community-dwelling adults. Other studies have also seen benefits to older adults through the use of small aquariums, which when in an ACF require little to no daily supervision by residents, whilst allowing for longer periods of human–animal interaction (Clements et al., 2019). Further research is required to fully comprehend the risks that these and other species may pose to older adults. Future research should also investigate risk differences between different companion animal species and settings.

It should be noted that pet animals may be at risk from their guardians. The most obvious is being injured by being fallen over or on (Stregowski, 2022). In addition, the long lifespans of species such as birds or reptiles can lead them to outlive their older adult guardians, leading to them to require rehoming, which puts further pressure on rescue centers and sanctuaries (Coulson, 2018). This was not the focus of this review, but it merits the same systematic approach as taken here in the interests of animal welfare/wellbeing and ultimately in the interest of shared human–pet animal thriving.

Conclusions and Recommendations

It should be noted that the majority, if not all, of the risks identified are ones that all pet guardians may face. However, the aging process leads to increased physical frailty and/or immunocompromised health and reduced social support, all of which can increase the likelihood of these risks having more severe outcomes. The aim of systematically identifying the risks was to increase awareness so that protective and preventive measures can be taken to help older people and the relationships they have with animals. Inherently, risk management recognizes that life is full of risks and a risk-free existence is not possible, nor indeed desirable.

There is a knowledge gap in the area of animals and risks to older adults. Further research is required to fully quantify the risks that arise from cohabitation, both in the community and ACF settings, but there is enough evidence for older adults to be safely engaging with pets and hence continuing to reap the benefits of the human–animal bond.

Disclosure Statement

No potential conflict of interest was reported by the authors.