Before the twentieth century, human medicine treated diseases with a pharmacopoeia pieced together from personal experience, professionally accumulated lore, and custom. A physician’s actions were based on whim, intuition, received wisdom or personal experience not governed by professional or scientific consensus. Now the medical profession is heading toward evidence-based medicine (Daly, 2005; Eddy, 2005), which is dependent upon the explicit and judicious use of current best evidence in making decisions about patient care, i.e. the application of the scientific method to medical practice, based on a foundation of critical studies testing the efficacy of individual and combinations of treatment. Psychiatry, with some resistance from the pharmaceutical industry, is also moving in the same direction (March et al., 2005; Jensen et al., 2005). Animal-assisted therapy (AAT) is a volunteer activity that has marginal acceptance based on the almost universal fondness for cute animals and a general belief that animals and nature are among life’s good things. If AAT is to gain acceptance as a legitimate treatment modality, much more information will have to be forthcoming. It is the purpose of this chapter to outline strategies for acquiring the information necessary to ground AAT in reliable evidence so that it might have a place in clinical medicine. The authors decided to adopt this approach because there has not been any critical evidence published that would necessitate a revision of the conclusion of our other articles on the subject (Beck, 2000; Beck and Katcher, 1984, 2003) or those of other researchers (Barker and Wolen, 2008; Wilson and Barker, 2003).
The first requirement for establishing animal-assisted therapy (AAT) as an evidence-based therapeutic modality is having the evidence. Unfortunately, the field from its inception has relied upon individual case reports, poorly designed studies, “pilot” investigation, studies published in books and proceedings volumes, and even self published in book form (Beck and Katcher, 1984). This kind of publication protects papers from the stringent review afforded by refereed journals. Two of the most famous papers in the field are the budgie study (Mugford and M’Comisky, 1975) in which the number of subjects was too small to permit statistical analysis and the original, self published, evidence in support of the “Eden Alternative” (Thomas, 1994) in which the evidence consisted of four graphs with no indication of the number of subjects and no statistical analysis. There is a general impression that “Edenizing” a nursing home lessens medication usage and most observers believe it is a better alternative to the general nursing home facility (Thomas, 1996). In the years since Levinson’s (1969) initial review of the state of the field, two specialty journals have appeared to give authors a venue for publication, but the preponderance of citations in AAT papers from these two journals, Anthrozoös and Society & Animals, still speaks to the failure of authors to find a home for their studies in the journals that influence clinicians in fields of psychology, psychiatry, nursing, social work, and education. Most articles about human/animal interactions published in more traditional medical journals have been, by and large, studies of the relationship between pet ownership and human health or review articles (e.g. Friedmann et al., 2003; Katcher et al., 1983; Ulrich, 1984; Walter-Toews, 1993).
Evidence-based medicine rests on firm pillars of epidemiological evidence and controlled studies testing the interventions suggested by the epidemiological investigation. We would not be advocating lowering of blood lipids, cessation of cigarette smoking, exercise regimens, or the Mediterranean diet if there were not unequivocal longitudinal and cross-sectional (synchronic) studies suggesting a strong relationship among cholesterol, cigarette smoking, exercise, and diet and coronary artery disease. Equally strong studies suggested that lowering cholesterol, exercising, and smoking cessation reduces risk from that disease. The epidemiological evidence for a relationship between pet ownership and overall health, or specific disease incidence is at best inconsistent (Friedmann, 2000; Nimer and Lundahl, 2007; Virués-Ortega and Buela-Casal, 2006). The literature on pets and health contrasts with the much larger body of evidence that relates social support to health (Giles et al., 2005; Ross, 2005; Schone and Weinick, 1998; Subramanian et al., 2005; Virués-Ortega and Buela-Casal, 2006; Wilkinson and Marmot, 2003). In fact, some early studies may conclude that cat ownership does not improve health and may even be detrimental (Friedmann, 2000; Friedmann and Thomas, 1995; Rajack 1997). Later studies find that cat ownership can be protective against cardiovascular diseases (Qureshi, 2009).
What is needed at this juncture, even before contemplating the difficulty of clinical trials in this area, is a firm foundation for predicting positive health benefits from pet ownership. Published results are generally positive but often only one kind of human/animal relationship is considered (Nimer and Lundahl, 2007). At the present level of our knowledge, we have to entertain the notion that some kinds of pets, cats, for example, may be significantly less beneficial than dogs (Headey, 1999; Siegel, 1990) or even have detrimental effects. Exposure to house pets decreased the risk of non-Hodgkin’s lymphoma, but contact with cattle and pigs increased the risk (Tranah et al., 2008). In many cases, dogs alone may be important to the intervention by stimulating walking (Bauman et al., 2001; Ham and Epping, 2006; Messent, 1983) or improved social interaction with others (McNicholas and Collis, 2000; Thorpe et al., 2006; Wells, 2004). The impact of animal contact can be different for male and female owners (Miller et al., 1992) or be especially important for a specific age group, as dog and cat contact early in one’s life protects a person from allergy in the future (Bufford et al., 2008; Ownby et al., 2002). Indeed, it may be useful to distinguish the value of animal contact apart from the benefits of human/human contact which has pronounced and well-documented effects (Giles et al., 2005; Lynch, 2000; Schone and Weinick, 1998). Once such epidemiological evidence is at hand it would be possible to make specific recommendations for the therapeutic placement of pets. However, there is a peculiar problem with framing therapeutic interventions with pets that should be recognized.
Evidence-based medicine is absolutely dependent upon random assignment therapeutic trials for its factual base. The trials need not be double-blind; obviously a study of diet or exercise cannot be a double-blind trial. Animal contact, as an experimental variable, can be compared to a comparable control variable, like music (Voith et al., 1984). But there are some circumstances in which random assignment intervention trials present real difficulty. It is universally recognized that church attendance, even when other variables are controlled for, is usually positively associated with better health (Ferraro and Albrecht-Jensen, 1991), although the opposite as been reported (Cline and Ferraro, 2006). The effect is not trivial and much more consistent than the evidence for the relationship between pet ownership and health. However, having that information it is difficult to frame a recommendation for a therapeutic study. Do you assign people to attend church and compare them with people who read the New York Times on a Sunday morning? Is it possible to assign people to attend church and expect the same effects as you have in people who attend by conviction (or their spouse’s conviction)? Attempts to randomize prayer could not find any impact on health, though other neotic (intuitively useful but not easily assessable) therapies such as music, imagery, and touch did have some effects (Krucoff et al., 2005). There are problems that arise when a therapeutic effect is potentially dependent upon a social relationship. For someone attending church a social relationship exists between a person and both God and the congregation. For the pet owner, a social relationship exists between the owner and the pet and also the people who relate to him through the pet. Can such social links be created by assignment?
Moreover, studies of pet ownership and health introduce an added moral complexity to therapeutic trials. What kind of responsibility does the experimenter have to the animal used in study? At the very least, the experimental team must monitor the health and well-being of the animal and the tensions, if any, the animal creates in the host family for the duration of the study. The team should also consider if it is incumbent upon them to remove the pet from the adoptive home if its welfare is in danger. Unfortunately, that places the investigators in an ethical dilemma. They are interested in completing the study and ending the participation of a study member by removing the pet if it threatens the integrity of the study. Without some neutral arbiter, the pet’s welfare cannot be assured.
Although dogs are a major focus of people in the field—perhaps because of their own attachments (see later) or because support for studies often comes from the pet industry and dogs contribute disproportionately to that industry’s income—consideration should be given to other less demanding animals, in the absence of clear indications of a clear therapeutic advantage of dogs. In our studies with children, fish, amphibians, reptiles, and small mammals elicited positive emotional responses and active caregiving responses, and signs of bonding from children and adolescents (Katcher and Teumer, 2006; Katcher and Wilkins, 2000) Many of these animals are contained in cages, and make less social demands on their caregivers than animals such as dogs and horses.
In other studies, having animals as a focus of interest can improve family dynamics. Parents who were given a bird feeder and an initial supply of birdseed identified family involvement as a particularly beneficial aspect of the program, and 90% of contacted families were still feeding birds one year after program termination (Beck et al., 2001). In general, children frequently turn to their pets as a way of mitigating life’s stress, such as starting school for the first time (Melson et al., 1997). Alzheimer’s disease patients, who are often too agitated to eat properly, are less agitated in a room with a fish tank. They gained weight and even expressed fewer disruptive behaviors after a fish tank was placed in their dining room (Edwards and Beck, 2002).
Even just observing animals can reduce cardiovascular stress (Wells, 2005) so there is even reason to propose the use of robotic animals, either as a control experience or as the experimental intervention (Kimura et al., 2005; Melson et al., 2005; Yokoyama, 2005). There are none of the moral concerns attendant to placement of a live animal. Problems introduced by virtue of personality differences between breeds of dogs do not arise, and the robotic animal does not place any demands on family resources (i.e. cost of food, time needed to exercise the pet, trouble in cleaning up, and effects of noise). The use of such robotic animals will be dependent upon obtaining data about the duration of interest shown by owners, frequency of interaction, and measures of interaction that go beyond the subject’s recollected account (i.e. electronic modification of the robot to determine the frequency and duration of use). Robotic animals would also be useful in determining the limits of the human tendency to project individuality, personality, and emotional attachment onto animals (Kerepesi et al., 2006; Kramer et al., 2009; Shioya et al., 2005).
The second large area of activity that is subsumed under AAT is the direct use of an animal as a therapeutic tool in a patient encounter. These interactions are relatively brief in duration, they are guided by the therapist, and the client does not take permanent possession or responsibility for the animal. AAT as practiced now is not conceptualized as primary therapy (Beck and Katcher, 1996). There are no studies in which all medications are stopped and the patient is treated only with AAT and the control group given a placebo. AAT is by nature a kind of auxiliary therapy akin to art, horticultural, dance, and occupational therapies. However, AAT is a bit more peculiar than art or dance therapy. No one would teach only pottery in occupational therapy, or Balinese shadow dancing in dance therapy. Yet it is the convention of AAT therapists to work only with the animals to which they are strongly bonded. Most therapists work only with their own animals. This bonding between therapists and their pets (Katcher and Wilkins, 2000) creates problems not only because of the issue of bias, but also because choosing the best animal for a patient involves changing therapists, and there is no body of professionals who can speak to the relative merits of different kinds of animals or (see earlier discussion) animal surrogates.
Sometimes intellectual clarity can be obtained by a kind of thought experiment. We would like to have the reader imagine two pentagonal buildings a hundred yards away from each other. One has a series of rooms built about a central court with outward facing windows that overlook an encircling ring of trees, shrubs, and lawn, as well as windows looking into a central court which is illuminated by a skylight and has a fountain with a pool inhabited by koi (Cyprinus carpio). Each of the rooms is equipped to have a different kind of experience with animals. One is a large space that can be used for agility trials in dogs or even exotic beasts such as llamas. Another contains a collection of smaller animals in cages that can be tended, played with, and serve as a stimulus for learning. A third might be a large aviary with provision for tending plants as well. Other rooms are smaller and can be used for intense work with a single animal, or play with a robotic animal of some sort.
The other building has no outer windows, but where the windows would be, large liquid crystal screens display continually changing images of colorful geometrical shapes. There are windows that face onto the central court but the court brightly illuminated as well contains a number a sculptures of intricate inorganic shapes. Within the rooms there would be activities such as are usually part of occupational therapy—painting and working with other media, music and dance.
With those two facilities at the disposal of a research group it would be possible to randomly assign children to a type of conventional auxiliary therapy such as occupational therapy, art, dance or music as the control experience, and some form of AAT as the experimental therapy. The experimental therapy could be chosen by the diagnostic team and not be a therapist specializing in whatever animal that claims his/her affections. Observers could be chosen who are not recruited from the ranks of animal enthusiasts and hence do not have an obvious bias.
Obviously, this perfect design is not possible but it is good to have an idea of what would be ideal. Now the challenge is to design studies that more approximate the ideal than what we do now. Knowing what the perfect study could contain helps identify the failings and possible confounders, which then can be mitigated with a variety of design tools, such as controls, stratification, pilot studies, and sample size.
The focus of this volume and most of the writings in the field on animals and nature as therapy misses the most salient questions at this time in our history, culture, and social organization. Those questions revolve around the effects of subtracting nature and contact with animals from our experience as children and adults in industrialized societies. Indeed, the same questions could be asked about the huge increase in urban growth in the non-industrialized world as well. As late as 1910, more than half the population of the USA was found in farms. With the advent of the automobile and the decline in the family farm in favor of industrial farming, as well as the progressive usurpation of farm land by suburban growth, animals and uncultivated open spaces moved further and further from our daily lives. As late as 50 years ago, live animals were to be found in butchers’ shops, and fish markets displayed whole fish. Now children never see an intact animal displayed in shops either dead or alive.
There is a long history documenting the importance of contact with nature for all (Ulrich, 1993) and the special roles of nature for children (Kahn, 1999; Kahn and Kellert, 2002; Melson, 2001; Rud and Beck, 2003). However, with the advent of television, and then video games, and the increasing anxiety about dangers to children if their play is unsupervised, fewer and fewer children are spending time out of doors, exploring nature and placing themselves in a position to see wild animals first hand (Louv, 2005). Organized sports are just that, “organized,” and the children are ferried to play on sterile greens where vigorous mowing and poisoning hold nature back. This secular trend toward decreasing experience with nature, and decreasing time spent out of doors, has gone along with increasing rates of ADHD (Kuo and Taylor 2004), juvenile obesity, and childhood Type 2 diabetes (Haslam and James, 2005) as more and more children spend less and less time out of doors. In a more metaphorical sense, both children and adults have developed a decreasing capacity to pay attention to what is out there in the real world and are increasingly locked into a virtual world of television, computers, computer games, iPods and cellular telephones that draws the person away from what is directly about their world.
We desperately need to know what the effects of the subtraction of nature and nature-directed activity have been in the lives of our children. If there is any general conclusion that we can carry away from what we know about AAT and the effects of animals on health and mental state, it is that these effects may be large, especially in people who are vulnerable by virtue of a predisposing genetic or environmentally acquired constitution. The importance of knowing the harm this great subtraction has accomplished outweighs the understanding of artificial contact such as occurs between patient and therapist or volunteer in AAT and the clinical significance of any limited contact between patients and AAT practitioners.
What follows is a list of questions that has considerable value in setting an agenda for human/animal relationship research:
How much of the rapid growth of children diagnosed with ADHD and children in special education has to do with the increasing lack of experience with animals and nature as well as decreased opportunity for physical activity?
How much of the increasing difficulty that boys experience in completing high school and college stems from unmet needs for activity, and contact with animals and nature?
How could contact with nature and animals be used to reform our present method of schooling in which learning and physical inactivity are so strongly linked?
How does the lack of experience with animals and nature affect our capacity for language, narration and metaphor?
How does human and animal companionship interrelate: are they additive or competitive or both? When can one substitute for the other, and when can it not?
What changes in our social structure can bring about a greater interaction between people and nature, if it is found that lack of such interaction has detrimental effects?
These are just some of the questions that can be asked, but they all focus on the larger problem: the decreasing level of contact with nature and animals in our society. They are also aimed at what mechanisms can be instated to create a sustained relationship between animals and people, not a temporary clinical relationship based on perhaps a misapplied medical model to what is really a societal problem.
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