Abstract

Many studies using animals, cats, dogs, and fish and robotic models of animals have attempted to determine the benefits to health associated with the pet’s presence or animal-assisted therapy for the older. A few small, unblinded studies have revealed changes in the behavior of people with dementia treated with animals. Studies that test animal use for the treatment of schizophrenia and depression have had mixed results. Animals can provide benefits intangible to the mental well-being of older people, like relief from boredom and social isolation. However, these benefits have yet to be studied in depth. Several studies investigating pets’ impact on physical health have suggested that pets can reduce blood pressure.

Additionally, dog walkers engage in more physical exercise. As evidenced in epidemiological studies and some preliminary studies, walking with dogs has been linked to a lower risk of complications for patients suffering from cardiovascular disease. Pets can also cause harm as they can be costly, and their owners may be more likely to be injured. Zoonotic infections and bites are believed to be possible; however, the frequency at which this happens within the situation of pet ownership or therapy using animals is not known. Despite the low quality of research methods on pets, after many years of research, the benefits of pet ownership and therapy with animals are likely to persist due to the positive emotions that many people feel towards animals.

Introduction

Most U.S. households 1, 2, and nearly 50% of people who are elderly have pets 33. Studies involving pets and other animals that aim to enhance the overall health and well-being of older adults have been conducted with various animals, such as cats, dogs, and even manufactured animal models of animals 4[ 4 ]. This paper reviews evidence of the effects of animals’ health on older people. Due to the limited number of published documents that were reviewed, a systematic review was not conducted. The studies were found by performing a PubMed search that included terms like “pets, elderly, and animal-assisted.” The additional articles were retrieved from the reference lists of the original papers found.

Potential Benefits of Animals

2.1. Effects on Mental Health

The most widely studied application of animals that have elderly participants has been to reduce the symptoms of cognitive disorders such as anger 55. The studies in all cases were blinded, but not all of them were controlled. However, the majority, but not all, demonstrated tiny but statistically significant improvements in symptom scores for behavioral disorders when using animal-assisted treatments.

The only study to use the bird was unique in observing that birds provided positive psychological effects to healthy older adults; 144 individuals with no impairment to their cognitive abilities who resided in residential care facilities located in Italy had the opportunity to interact with the canary or a plant or neither ([6]). 66. Individuals entrusted with caring for a plant or a canary received instructions on how to care for the animal. They participated in an intervention that lasted for three months, and the specifics needed to be outlined in the research paper. People who looked after the bird scored significantly better after the program on the subscales of psychological symptoms on The Brief Symptom Inventory and LEIPAD-II Short Version, which subjects from the two other categories did not.

Other research studies examined the impact of pets on demented people (see Table 1.). A dementia center for U.S. veterans tested using a dog as a pet to encourage socialization. Twelve patients with dementia displayed an impressively higher number of social behavior, including smiling or chatting when they were with the dog. This suggests that dogs could provide benefits in addition to any impact on cognition 77.

Table 1 Studies on the use of dogs in dementia.

Another study that was not controlled indicated that animals may aid in reducing problematic behavior in demented people. The study enrolled residents in two U.S. nursing homes with MMSE scores of less than 15 and was treated with therapy with animals 88. The participants in the recreation room for an hour each day bonded with a pet and its trainer. They could engage in various activities, including petting, feeding, and grooming the dog, interacting with the trainer, and talking about pets they previously had. Subjects scored a mean of 25 percent and significantly higher ratings on the CMAI measure of behavior disturbances after the intervention.

Two other studies also evaluated the effects of animal therapy on cognition and mood among people with cognitive impairment. Twenty-five patients with moderate delusions in an elderly care facility were divided into groups 99. For the group that was in the intervention (mean Folstein Mini-Mental (MMSE) score 15.3, median 15-question Geriatric Depression Scale (GDS) score 5.9), The participants participated in a weekly hour one-half activity over 60 days during which they interacted with specially trained dog therapy pets. Participants either walked with or played with, petted, or held the dogs under the guidance of the trainer. The control group (mean score for MMSE of 18.3 and a mean GDS score of 7.4, which wasn’t significantly higher than those in the treatment group) participants watched the animals as they entered the nursing homes but did not engage with them. After the intervention, both groups showed increased MMSE scores and decreased GDS scores. However, the differences between both groups in pre-and post-intervention values were insignificant. Another study looked at four demented moderately to severe patients of a residential facility that were recorded for their behaviors before and during the session with an animal 1010. Residents showed significantly fewer signs of agitation and more social behavior when in therapy with animals.

Another study focused on whether animals may provide physical benefits to patients with dementia. The trial also utilized fish that required the participants to handle animals. The study found that patients with dementia who resided in various nursing homes successfully increased their weight after putting fish tanks in place 1111. Two hundred and twenty-two elderly people lived in areas for dementia in 3 nursing homes that had tanks in the dining and recreation rooms that provided a twenty-inch viewing area and background lighting to help compensate for the possibility of visual impairment in residents were compared to another group of residents that had the “scenic ocean picture” added to the same rooms. The residents of each home had different times of exposure to the tanks or the images. If the data of those who were exposed to the tanks were gathered together, there was a 1.65 pounds weight gain in the period between the three months before the tanks were placed and four months post-when the tanks had been put in (), but there was no increase for the group that was controlled.

Animals may also provide advantages to people who have dementia in addition to improving their ability to interact with others, according to several studies. In one study that was blinded, 33 people who resided in the nursing home had contact with animals over 41.1 hours of therapy with animals in addition to 33.8 hours of therapeutic exercise without animals 1212. Conversations that lasted for a long time between individuals were much more likely to occur in therapy groups when pets were present. However, small conversations were more common in the absence of animals. In a separate study, an audiotape recorded the interactions of 36 residents of nursing homes in 90 minutes of occupational therapy with or without dogs present 1313. The residents were likelier to converse verbally with the dog during the sessions. The third study, which included 13 mentally ill residents, showed a mechanical dog that could stand up and wag its tail or a robot dog who could respond to seventy-five commands 14 The results showed that the robotic dog could react to seventy-five commands [ 14. Subjects responded to both toys similarly by speaking to them or shaking their hands whenever they moved.

Nurses have shared their personal, qualitative experiences that animals help alleviate boredom and loneliness, encourage social interaction, provide a variety to their lives, and indirectly suggest other benefits of the human-animal interactions that have not yet been documented in clinical trials 5, 15[ 5, 15]. In a survey, nursing staff in an intermediate care facility described their opinions about “cat mascots,” animals who spend their days in unit 16[ 16. There was no formalized supervision of interactions with the cat and patients or formal measurements of the exchanges. However, nurses shared that the cats enhanced patient interaction with companions and the environment and that patients were happy with their presence.

Pets also have the potential to affect the behavior of demented owners. A study conducted in comparison showed that pets with dementia had a lower likelihood to display verbal aggression but were like non-pet owners concerning the probability of hyperactive, vegetative, or psychotic behavior 17[ 17.

So far, however, there has been no research about the role of animals in patients with dementia have identified a way to how animals could influence the behavior of these people. Animals may be a source of distraction to stop disruptive behavior or act as a model for human interaction to understand or develop social skills.

Many studies have also explored animal experiments for treatments for depression. However, they have had mixed outcomes. A small study showed that even an hour-long intervention could provide some benefits. Thirty-five patients about to undergo electroconvulsive therapy (ECT) took an hour with the dog and trainer or for the same amount of time in magazines before ECT treatments 1818. All subjects received both kinds of pretreatment daily. The subjects reported less anxiety regarding the imminent ECT measured on visual analog scales when they were having sessions with their dogs. In a similar study, the patients who were depressed spent in anticipation of ECT in rooms without or with aquariums. Aquariums’ presence didn’t affect the anxiety and fear symptoms they experienced in 1919.

Animal-assisted therapy has been a possibility as a treatment for depression among institutionalized patients in several studies. In one study, 28 patients of an Italian nursing facility had three-hour therapy sessions every week for a month and a half with a cat, or there was no change to their routine in 2020. A nurse was in charge of the residents in a room for therapy where they could play with cats or interact with them. People who played with the cat did not exhibit any significant differences regarding Geriatric Depression Screen score or cognition, as measured by MMSE. However, they did experience a reduction of 16 points in blood pressure in the systolic region () and five-point lower diastolic blood tension () compared to those who did not interact with the cat. A second survey found that the subjective ratings of pet affection correlated with higher scores of depression-related symptoms in those older and living in rural settings 2121. In another study of 68 residents in nursing homes in Australia, people who went to visit dogs were less stressed, tired, and confused. They also reported less depression 2222. Patients who were receiving chemotherapy were separated into two groups. One of them could attend a weekly hour of therapy that included a pet. The other group didn’t have 2323. Patients who attended sessions where a dog was present rated their depression and anxiety as being half as severe as those who were not. When taken together, these findings provide a somewhat small benefit for dogs in people who are depressed.

A meta-analysis was compiled of five studies on the effectiveness of activities aided by animals in treatments for depression among institutionalized patients ([24]). 24[ 24 ]. The five studies whose data were pooled to form the meta-analysis were published in a Journal of Science. Four were published in doctoral dissertations, and the fifth was published as an article in a book nearly thirty years back. The meta-analysis concluded treatment could help alleviate depression symptoms with the “medium effect size.” The meta-analysis and the previously referenced manuscripts provided any information on possible mechanisms for the effect.

Other studies have examined whether pets could aid those with schizophrenia. Two studies indicated that animals might improve social behavior among people with schizophrenia aged over. Twenty people with schizophrenia aged at least sixty-five and a visit of three hours each week over an entire year with a pet or cat and a therapist 2525. The patients were taught how to walk around with their pets on leashes and bathe, feed, or groom the animals. The control group could participate in weekly discussions about news alongside the therapy group for animals. Animal therapy-exposed schizophrenia sufferers significantly improved their mean scores on social functioning, as measured by the scale for Social-Adaptive Functioning Evaluation. At the same time, the participants in the control group didn’t. There was no difference between groups regarding surveys that assessed the subjects’ ability to control their impulses or self-care.

In a separate study of 21 patients who have schizophrenia, they were split into a control and intervention group 2626. Each group had 45-minute weekly meetings with a therapist for 25 sessions. The handler and a therapy dog were also involved in the intervention program. This dog became the center of the interventions designed to improve social skills, communication, and cognitive rehab. The control group also had similar sessions, with the exception of the dog. The participants who were in the intervention group had significantly higher scores in the social contact score of the Living Skills Profile and total score on the Positive and Negative score scale for Symptoms.

A few studies have found that people with schizophrenia have advantages over pets. The patients of a psychiatric hospital aged over fifty-eight in one study were randomly assigned to attend five sessions for an hour daily, pets or in an exercise group 27[ 27. The two groups had no differences in a forty-question psychiatric symptom score. Additionally, the trials of therapy with animals in people with mental disease and qualitative research involving small groups of people recovering from acute episodes of mental illness have revealed the subjects’ perception of the advantages of having pets, like companionship and increased confidence in themselves 2828. But, some of the issues were concerned about their pet’s care obligations and mourned the loss of their pet.

In addition, several studies have suggested that animals provide social or psychological benefits to seniors, regardless of their health. In one study, animals’ impacts on the loneliness levels experienced by long-term care residents were evaluated with a questionnaire 2929. Thirty-five residents of a nursing facility had experience of over two and half years interacting with various animals, including cats, dogs, and rabbits, for two hours per day 3030. They scored higher on the Patient Social Behavior Score score both before and after the treatment. In a different study, 45 residents from three facilities were split into groups who received 30 minutes of animal-assisted therapy every week for one month and a half-hour of the same treatment three times per week or no therapy at all. Patients who received animal therapy had lower scores when they took the UCLA Loneliness Scale than those who did not. A case study that included a robotic dog helped improve the loneliness scores on a single assessment instrument for five patients with chronic illness ([31]]. 3131. In a study of qualitative data, dogs with a lifespan of 70 in Austria said that their dogs brought comfort and a sense of reason 3232. In very few instances, animal therapy can offer a positive experience to severely sick residents in intensive-care unit 3333.

2.2. Effects on Physical Health

Numerous studies have documented evidence of animals’ impact on older people’s physical health. Many have tried to quantify the biological benefits of the presence of animals in their effects on stress (see Table 2.). One study exposed pet owners with hypertension to the pressure of completing an arithmetic challenge and then delivering the speech 34]. The researchers instructed half of the subjects to get an animal, and the entire sample was studied again within six weeks. The subjects who had a pet experienced a significantly lower increase in diastolic and systolic blood pressures in response to the stressor than those who didn’t. In a further study, being surrounded by a dog in the room slowed the increase in blood pressure due to stress caused by public speaking 35]. Eleven older people living in the community suffering from hypertension, with a mean age of 81.3, were asked whether they would talk with or without a pet while blood pressure was measured. The participants who spoke in the presence of a dog showed substantially lower diastolic blood pressure (mean difference of 12.8 mmHg ) compared to those who did not speak without the animal’s presence. A further 10 dog owners who were healthy canines achieved significant diastolic and systolic blood pressure reduction and emotional measures when performing a stressful task, regardless of whether their dog or not [36]. The results showed a higher improvement in outcome measures when the subject’s dog was utilized, and the test duration was up to one hour. Also, in a tiny study of elderly residents in communities aged 65-91, One group was visited weekly by an animal-friendly nurse for a month.

In contrast, another group received visits with dog 3737. People close to the pet showed significantly lower systolic and diastolic blood pressures than those who didn’t (mean decrease of 8 mmHg diastolic and systolic with a significant difference in the group that received the intervention from the baseline). When taken together, these findings suggest that pet possession on the physiologic consequences of stress.

Table 2. Table 2 Studies on the effects of animals monitoring blood pressure.

Studies on the epidemiology of pet ownership suggest that pets may reap physical benefits such as higher blood pressure and more physical activities. Of 5741 participants from Australia, the people who owned pets had significantly lower blood pressure at rest with a mean 5 mg/dL lower cholesterol and triglyceride levels of 84 mg/dL, which were statistically significant 3838. In another study of 1179 people who were elderly (mean age of 70), pet owners showed an overall lower systolic arteriolar mean and pulse pressures, as well as a lower risk of developing hypertension (O.R. = 0.62) [39].

Another study suggests that dog walks encourage people to engage in physical exercise (see Table 3.). In another study, dogs owner in Canada (not only seniors but including people between the ages of 80 and 80) had a higher likelihood to go to multi-use or walk-through areas than people who did not have dogs 4040. A study of 5902 people in the U.S. observed a positive correlation between dog walking and the amount of time spent walking 4141. A dog’s owner was more likely to exercise more than 150 mins each week (O.R. 1.69 95 percent C.I. 1.13-1.59) as well as also more likely to engage in physical activities during their leisure time (O.R. 1.69; 95% CI 1.33-2.15). Dog walking was also linked with the likelihood of walking among 608 Washington residents () () 4242. A recent study of 545 Scottish participants, all at least 65 years old, showed that pet owners were significantly more likely to declare their highest fitness levels than people who did not have dogs 43]. In a study of 3,075 older people (aged 70-82) who resided in Memphis and Pittsburgh, the dog owners had twice the likelihood. Still, non-dog owners were half as likely to engage in physical activities compared to those who didn’t have pets 4444.

Table 3 Studies regarding the effects of animals on physical exercise.

Walking with dogs can encourage people to participate in other beneficial physical activities that help preserve their function. In the most comprehensive study to date to date, that of the California Health Interview Survey, with more than 55,000 participants dogs, pet owners more frequently were walking as a leisure exercise than those who do not have pets (O.R. 1.6 (95 percent C.I. 1.5-1.8) however, they were less inclined to take a walk to get around (O.R. 0.91; 95% CI .85-) [ 45]. An epidemiology survey found that for more than one thousand people at least 65 years old in Canada and Canada, the decline in capacity to carry out everyday activities of those who did not have pets deteriorated at a greater rate than that of pet owners 46]—in a Japanese study of 5283 adults up to the age of 79, dog pet owners had 1.54 percent more likely to achieve the recommended levels of exercise 4747. Of 127 people who were elderly living in Colorado pet owners, those with pets were more active () while having lower cholesterol levels () compared to people who did not have pets 4848.

But, having a dog may not ensure more physical exercise. In an Australian study, the owners of large dogs were more active than owners of smaller dogs. Furthermore, dog ownership did not correlate with a higher likelihood of achieving suggested physical activity levels 49]. While the papers looking at the impact of dog walking on physical activity have yet to address the mechanisms specifically, it is possible that, logically, the necessity to exercise a dog could cause a desire to be more active. The increased physical activity could be more closely linked to the pet’s needs than their owners.

Pet ownership could benefit those suffering from heart diseases (see Table 4.). Participants in a clinical study of antiarrhythmic drugs with dogs were less likely to die in one year than other people, including those with different breeds of animals 5050. Animals owned by owners discharged from a coronary care facility were likelier to live within one year 5151. Patients who suffered myocardial infarction during the last year and exercised their dogs for 15 minutes three times a day increased their endurance using stationary bikes () 52). 5252. Further analysis of a study where 460 pet owners were implanted with defibrillators (mean ) showed that the presence of pets made participants less likely to be killed () over the next 2.8 years 5353. In a separate study, seventy-six patients suffering from congestive heart disease were split into three groups: one of which was exposed to the dog at 12 mins, another of whom stayed with a person who stayed for 12 mins, and the third of them was not exposed to either 5454. People exposed to the dog showed lower systolic and pulmonary artery capillary wedge pressures and decreased serum epinephrine levels. Sixty-nine patients with congestive heart failure participated in an ambulation-training program that involved walking with a dog and a trainer 55]. When compared with a “historical sample” of congestive heart failure patients, those who walked with dogs were twice as long as those in the “historical sample” (mean 230.07 steps/day against 120.2 steps/day ). Some studies do not suggest that pets can help prevent heart disease. In one research study that followed patients admitted to a hospital with “acute coronary syndrome,” those who had pets were more prone to dying or rehospitalization a year after the initial hospitalization 56]. Despite the overwhelming weight of evidence, it is not surprising that the American Heart Association has released an acknowledgment of the role and causality of having a pet in reducing heart disease risk 57].

Table 4 Studies about the use of animals in the treatment of cardiovascular disease.

Harms of Animals

Although using animals and pets could bring several health benefits for older people, there are risks too. Pet owners can fall and suffer fractures due to their pets. The US Centers for Disease Control and Prevention reported that there were 86,629 slips each year that were attributed to dogs and cats, with an average incidence of 29.7 per 100.000 individuals per year from 2001 until 2006 38]. The elderly with a higher age experienced the highest rates of injury (68.8 for those aged 65-74 in addition to 70.6 for those aged 75 and older), which is more than twice that of the people between 35 and 44 (28.6). A series of cases from Australia also documented 16 fractures among older adults aged at least 65 and 59 at the time of injury. Most of the victims were women. Those who suffered injuries typically tripped over their pets or fell as they bent downwards to feed them. The pets were mainly cats and dogs, but they also had animals, goats and a donkey.

There could be other harm. Additionally, there could be other harms. Pets can be costly, complicated, time-consuming, and expensive to manage. The lifetime cost of a dog that is average size can be as high as $10,000, and a cat can cost $8,000 11. Pets require adequate nutrition, shelter, hygiene, and veterinary treatment 6060. Seniors may not be capable of providing this treatment due to cognitive or physical limitations than younger individuals.

Additionally, pets could cause damage to an elderly homeowner’s property, even though there aren’t any reports in medical journals. Pets that aren’t protected correctly by their owners may also pose a risk to others and the environment. Pets could hurt others, damage their property, cause fear, or create mistrust. Animals could damage the surroundings (e.g., destroying plants and animals or causing trash).

Older people in institutions may have more difficulty interacting effectively with animals. A qualitative study of staff members’ reactions to the mascot of an institution cat said that the residents put the cat in the garbage and a toilet and almost hit its tail on wheelchairs 1616.

Animals can cause trauma and infection to humans. Human infections caused by pets have been cited as a potential adverse effect of pet ownership among the elderly 60]. More than 200 Zoonotic infections are present 62], but their precise incidence among elderly who have pets or engage in animal-based treatments hasn’t been determined and remains undetermined. There is also the possibility of traumatizing injuries from animal bites and scratches. However, the frequency at which this occurs and the effect of such events have yet to be discovered. The report above of the mascot of an institution’s cat said that a cat smacked the patient but did not provide further information about the incident or any other human injuries 1616.

Pets may also be a source of psychological harm. Humans may become highly connected to their pets. Even when their pets pass away, they can experience grief-related symptoms similar to those accompanying the loss of others 32, 60[ 32, 60. The findings of any investigation of these losses’ effects on older people’s human health are not reported.

Future Directions and Conclusions

Initial studies have indicated the possibility of benefits from animals on both the psychological and physical well-being of humans. Despite more than 40 years of study, the studies are still preliminary. They are further complicated by methodological issues, such as the small size of the sample and a lack of adequate methods of control, as well as blinding. An analysis of research conducted on animals over ten years ago identified some obstacles 63 which must be overcome, including access for animals to subjects in research settings, fears of zoonotic diseases, and the lack of standardized survey instruments and the hiring of handlers. There still needs to be masked animal studies.

Furthermore, the impact of differences in the characteristics of humans (e.g., the differences in ethnicity, education, and income) still needs to be determined. In a study, elderly Latino dog owners aged 66 took part in questionnaires about their attitudes towards their pets and their health 6464. A majority of them believed their dogs to represent the “best friends” and “reason for getting up in the morning” and their overall health to be much better “than most people,” and seventy-five percent considered the health of their pets to be “excellent.” Future investigations will help to clarify these influences.

So far, research about the impact of animals on physical and mental health has found only modest positive effects. Studies of therapy using animals showed improvements in the scores of behavioral symptoms with a small sample of patients with a limited time. Studies on the impact of animals on health, specifically epidemiological studies that suggest that having animals could reduce the risk of heart disease, are more reliable scientifically. However, prospective studies showing clinical benefits must be conducted. The use of animals in new ways could be tested in the future. In an early report, the dog was taught to detect melanomas in humans by the smell 6565. Using animals as pets and as therapy can also cause harm. However, their prevalence is scarce.

Moreover, these risks are less recognized than the advantages. There has yet to be a formal confirmation of whether the benefits outweigh the cost of caring and feeding, which are listed to show the comparability in Table 5. But, numerous reports discuss people’s subjective positive feelings toward animals. The positive emotions of emotional people towards animals and increasing evidence of their possible role in treating heart disease could motivate them to continue their utilization of therapy and their ownership.