Pet ownership and human health: a brief review of evidence and issuesBMJ 2005; 331 doi: http://dx.doi.org/10.1136/bmj.331.7527.1252 (Published 24 November 2005) Cite this as: BMJ 2005;331:1252
- June McNicholas, psychologist ()1,
- Andrew Gilbey, lecturer2,
- Ann Rennie, general practitioner3,
- Sam Ahmedzai, professor of palliative medicine4,
- Jo-Ann Dono, director3,
- Elizabeth Ormerod, veterinary surgeon3
- 1 Croit Cullach, Durnamuck, Dundonnell, Ross-shire
- 2Massey University, New Zealand
- 3 Society for Companion Animal Studies, Blue Cross, Burford, Oxon
- 4 Royal Hallamshire Hospital, University of Sheffield
- Correspondence to: J McNicholas
- Accepted 4 November 2005
Research into the association between pet ownership and human health has produced intriguing, although frequently contradictory, results often raising uncertainty as to whether pet ownership is advisable on health grounds
The question of whether someone should own a pet is never as simple as whether that pet has a measurably beneficial or detrimental effect on the owner's physical health. The emotional bond between owner and pet can be as intense as that in many human relationships and may confer similar psychological benefits. Death of a pet can cause grief similar to that in human bereavement, whereas threat of loss of a pet may be met with blunt refusal and non-compliance with advice on health.
We examine the current evidence for a link between pet ownership and human health and discuss the importance of understanding the role of pets in people's lives.
Is pet ownership associated with human health?
Research dating from the 1980s popularised the view that pet ownership could have positive benefits on human health. Benefits ranged from higher survival rates from myocardial infarction1; a significantly lower use of general practitioner services (prompting some researchers to speculate on considerable potential savings to health expenditure)2; a reduced risk of asthma and allergic rhinitis in children exposed to pet allergens during the first year of life3 4; a reduced risk of cardiovascular disease5; and better physical and psychological wellbeing in community dwelling older people.6 No studies have found significant social or economic differences between people who do or do not have pets that would adequately explain differences in health outcome, leading to the belief that pet ownership itself is the primary cause of the reported benefits.
Although the research did much to raise awareness of the importance that people attach to their pets, recent studies have failed to replicate the benefits. A review of the association between pets and allergic sensitisation found inconsistent results for cat ownership between studies of similar design, whereas dog ownership seemed to have no effect or even protected against specific sensitisation to dog allergens and allergic sensitisation in general.7 Other studies on the subject suggest that exposure to pets may be beneficial provided that exposure is sufficient, as lower levels may enhance sensitisation whereas higher levels may protect against sensitisation.8 Yet others suggest that the effects may heavily depend on age at exposure and type of pet.9
Similarly, recent research has failed to support earlier findings that pet ownership is associated with a reduced risk of cardiovascular disease,10 a reduced use of general practitioner services,11 or any psychological or physical benefits on health for community dwelling older people.12 Research has, however, pointed to significantly less absenteeism from school through sickness among children who live with pets.w1
Do we need a broader definition of health?
The main issue may not be whether pet ownership per se confers measurable physical benefits but the role that pets have in individual people's lives—namely, the contributions of the pet to quality of life or the costs to wellbeing through a pet's death. This issue embraces a broader definition of health that encompasses the dimensions of wellbeing (physical and mental) and a sense of social integration.
Three potential mechanisms have been proposed to explain the association between pet ownership and benefits to human health (fig 1).13 The first is that there is no real association between the two, rather that cofactors such as personality traits, age, and economic or health status impact on the decision to own a pet and thus produce an apparent link between pets and health. So far, however, evidence is lacking that any of these cofactors account for both health promoting attributes and propensity to own pets, suggesting that health benefits, when reported, may be attributable to some aspect of pet ownership.
The second proposal is that pets may enhance social interactions with other people, thus providing an indirect effect on wellbeing. Social contact has been long recognised as beneficial in that it alleviates feelings of loneliness and social isolation. Pets undoubtedly act as “social catalysts,” leading to greater social contact between people.14 These factors may be particularly important for those at risk of social isolation, such as elderly people or people with physical disabilities, who lack many of the opportunities for social interactions of their more able bodied peers.15
The third proposal focuses on ways in which pet ownership may exert a direct effect on human health and wellbeing through the nature of the relationship. Close human relationships have a powerful influence on wellbeing by providing emotional support. They may reduce perceptions of stressful events thus protecting against anxiety related illness, may give confidence that successful coping strategies can be found to deal with stress, and may enhance recovery from serious illness such as stroke, myocardial infarction, and cancer. These aspects of a relationship are collectively referred to as social support. Social relationships, or the lack of, seem to constitute a major risk factor for health, rivalling the effects of well established risk factors such as cigarette smoking, blood pressure, blood lipid concentrations, obesity, and lack of physical activity.16
The value of companionship
Companionship—a commonly stated reason for pet ownership—is regarded as theoretically distinct from social support in that it does not offer extrinsic support but provides intrinsic satisfactions, such as shared pleasure in recreation, relaxation, and uncensored spontaneity, all of which add to quality of life. Thus companionship may be important in fostering positive mental health on a day to day basis, whereas social support may be of particular value in buffering threats to mental health and wellbeing from real or perceived stressors. Figure 2 illustrates the inter-relationship between functions served by pet ownership and human health outcomes.15
Although research has primarily focused on human relationships as providing support and companionship, it is a short step to extrapolating these to pets. Studies have shown that the support from pets may mirror some of the elements of human relationships known to contribute to health.17 Although support from pets should not be regarded as a replacement for help from people, the fact that pets are not human confers certain advantages; the relationships are less subject to provider burnout or to fluctuations, and they do not impose a strain or cause concern about continuing stability. Relationships with pets seem to be of value in the early stages of bereavementw2 and after treatment for breast cancer.w3
Why pet ownership should be taken seriously
The question of whether a person should acquire a pet or continue to own a pet requires careful consideration of the balance between benefits and potential problems. About half of households in the United Kingdom own pets.w4 Most are valued as family members. Conflict between health interests and pet ownership can cause non-compliance with advice on health. Some sources estimate that up to 70% of pet owners would disregard advice to get rid of a pet owing to allergies,w5 whereas reports abound of older people avoiding medical care through fear of being admitted to hospital or residential care as this often means giving up a pet.w6
Over 90% of pet owners regard their pet as a valued family member
Reluctance to part with a pet may lead to non-compliance with health advice
Pets may be of particular value to older people and patients recovering from major illness
The death of a pet may cause great distress to owners, especially when the pet has associations with a deceased spouse or former lifestyle
Many people would welcome advice and support to enable them to reconcile or manage pet ownership and health problems whenever possible
The loss of a pet may be particularly distressing for owners if it was linked with a deceased spouse or if it offered companionship or social contact with people.18 For these reasons many people may appreciate help and advice on how to manage a pet in the event of a health problem in the family.
Animal welfare organisations cite allergies and the fear of zoonoses as common reasons for people giving up their pets. Yet in some cases this may not be necessary. Research from the University of West Virginia shows that simple, day to day hygiene and pet care can reduce allergic reactions by up to 95%.3 A recent review of pets in nursing homes provides a comprehensive list of potential health problems and steps that can be taken to avoid these.19
People do not own pets specifically to enhance their health, rather they value the relationship and the contribution their pet makes to their quality of life.20 Greater understanding among health professionals is needed to assure people that they do not need to choose between pet ownership and compliance with health advice.
References w1 to w6 are on bmj.com
Contributors and sources JMcN has special research interests in the influence of pet ownership on health and lifestyle. She was formerly based at the University of Warwick. Her current work is with Dogs for the Disabled, the Society for the Protection of Animals Abroad, and Cats Protection, UK. She is a member of the Society of Companion Animal Studies. AG gained his doctorate from the University of Warwick, researching the role of pets in the alleviation of loneliness. AR and SA are members of the Society of Companion Animal Studies. J-AD has a degree in psychology and is director of the Society of Companion Animal Studies. EO is chairwoman of the Society of Companion Animal Studies. References refer to primary sources located through MIMAS web of knowledge service/web of science records. JMcN wrote the article, with contributions from the other authors, and is guarantor.
Competing interests JMcN received a research award, 2000-2, from Masterfoods UK to investigate the role of pets in children's health. AG was employed as a research assistant at University of Warwick, 1999-2003, funded by Waltham Centre for Animal Nutrition.