The Prevalence and Implications of Human–Animal Co-Sleeping in an Australian Sample

Abstract

Sleep research is characterized by an interest in humans, with the realm of animal sleep left largely to ethologists and animal scientists. However, the lives of sleep-study participants and those with sleep problems frequently involve animals. For the majority of the population in developed countries who own pets, their waking lives are impacted by the duties of animal care and ownership. For many, their sleeping lives are also impacted through sharing their bedrooms or their beds with pets. Yet, little is known about the prevalence of human–animal co-sleeping relationships or their impact on sleep. The aim of this study was to determine the prevalence and implications of human–animal co-sleeping in an Australian sample. The study uses data collected from the 2012 Sealy Sleep Census, a national online survey of sleep wellness that included a sample of 10,128 after data cleaning. The population of respondents (aged 18–74) who co-slept with pets (n = 1,018 or 10% of the sample) was then matched to a sample of respondents who did not co-sleep with pets, according to gender and age. Those who co-slept with pets took longer to fall asleep (p = 0.029), were more likely to wake up tired (p = 0.025), and although they were not more likely to wake up due to a disturbance, those who did had a greater chance of being disturbed by dog barking/animals making noises (p < 0.001). However, there were no significant differences found in total self-reported sleep length or feelings of tiredness during the day. The continued practice of co-sleeping with pets suggests that there may be some benefits such as social support and social interaction, and increased feelings of personal security. The survey provides a preliminary understanding of the prevalence and implications of human–animal co-sleeping, and highlights areas for further examination of its implications on sleep research and clinical practice.

Full text

The Prevalence and
Implications of
Human–Animal Co-Sleeping
in an Australian Sample
Bradley Smith, Kirrilly Thompson, Larissa Clarkson
and Drew Dawson
Central Queensland University, Appleton Institute, Australia
ABSTRACT Sleep research is characterized by an interest in humans, with
the realm of animal sleep left largely to ethologists and animal scientists. How-
ever, the lives of sleep-study participants and those with sleep problems fre-
quently involve animals. For the majority of the population in developed
countries who own pets, their waking lives are impacted by the duties of an-
imal care and ownership. For many, their sleeping lives are also impacted
through sharing their bedrooms or their beds with pets. Yet, little is known
about the prevalence of human–animal co-sleeping relationships or their im-
pact on sleep. The aim of this study was to determine the prevalence and im-
plications of human–animal co-sleeping in an Australian sample. The study
uses data collected from the 2012 Sealy Sleep Census, a national online sur-
vey of sleep wellness that included a sample of 10,128 after data cleaning. The
population of respondents (aged 18–74) who co-slept with pets (n= 1,018 or
10% of the sample) was then matched to a sample of respondents who did
not co-sleep with pets, according to gender and age. Those who co-slept
with pets took longer to fall asleep (p= 0.029), were more likely to wake up
tired (p= 0.025), and although they were not more likely to wake up due to a
disturbance, those who did had a greater chance of being disturbed by dog
barking/animals making noises (p< 0.001). However, there were no significant
differences found in total self-reported sleep length or feelings of tiredness
during the day. The continued practice of co-sleeping with pets suggests that
there may be some benefits such as social support and social interaction,
and increased feelings of personal security. The survey provides a preliminary
understanding of the prevalence and implications of human–animal co-
sleeping, and highlights areas for further examination of its implications
on sleep research and clinical practice.
Keywords: companion animal, co-sleeping, dog, human–animal
relationship, pets, sleep
543 Anthrozoös DOI: 10.2752/089279314X14072268687880�
ANTHROZOÖS VOLUME 27, ISSUE 4 REPRINTS AVAILABLE PHOTOCOPYING © ISAZ 2014
PP. 543–551 DIRECTLY FROM PERMITTED PRINTED IN THE UK
THE PUBLISHERS BY LICENSE ONLY
Address for correspondence:
Bradley Smith,
Central Queensland
University,
Appleton Institute,
44 Greenhill Road, Wayville,
South Australia 5034,
Australia.
E-mail:
b.p.smith@cqu.edu.au
AZ 27-4.Text_Layout 1 10/13/14 12:54 PM Page 543

Companion animals, or “pets,” have been long associated with human societies. The
practice of pet-keeping dates back to the Palaeolithic hunters and early agriculturalists,
who kept animals as both a leisure activity (with inherent social and emotional rewards)
and functional asset (e.g., assist hunting, educational and play “objects” for children; Serpell 1989).
The sleeping arrangements of pets do not appear to feature in early anthropological accounts, with
the notable exception of ethnographies of Indigenous Australians. During cold nights, Indigenous
Australians were often reported to sleep alongside their dogs for warmth (Smith and Litchfield
2009). This led to the common Australian expression “three dog night”—the colder the night, the
more dogs you needed to sleep with to keep warm (Breckwoldt 1988).
Today, humans continue to show strong attachment to their pets, and often consider them
an important member of the family (Archer 1997). In return, companion animals are sources
of unconditional support, love, comfort, security and stability that also provide health benefits
(Smith 2012). These benefits are apparent for many Australians, with at least 60% of house-
holds owning at least one pet (Australian Bureau of Statistics 1995, pp. 168–171). Pet
ownership in Australia has remained relatively stable during the past few years; current figures
indicate that 36% of households own a dog and 23% own a cat (Australian Companion Animal
Council 2010).
Companion animals not only often live inside the home, many also share their owners’
beds or sleep in the bedroom (Beck and Katcher 1996). However, little is known about the
prevalence of human–animal co-sleeping relationships or their impact on sleep. The scant lit-
erature is limited to the uncommon risk of zoonotic diseases, animal bites, and implications for
sleep hygiene, especially regarding children with respiratory conditions. It would seem that
human–animal co-sleeping practices have been overlooked as topics of cultural, psycholog-
ical, or behavioral importance. Some research has been based on the untested assumption
that letting a dog sleep “on” the bed is indicative of a positive pet attachment (e.g., Katcher
et al. 1983, as cited by Archer 1997) and that the “pets privilege of sharing the master’s bed
elevates him above human children, who are usually banned from the parental bedroom at
night” (Beck and Katcher 1996, p. 20). Similarly, Franklin interprets pets in bedrooms as
indicative of their status as intimate family members (2006, p. 211).
Research reporting human–animal co-sleeping practices is piecemeal at best, using data
from non-dedicated or non-validated surveys such as those undertaken by the media and the
pet care and pet food industry (APPMA 2013). However, a picture of human–animal
co-sleeping practices can be sketched by drawing from various studies in the grey and academic
literature, using a variety of tools and spanning several decades and populations. Various stud-
ies from around the world report that approximately half of pet owners let their pet sleep in their
bed with them during the night (Katcher et al. 1983; Albert and Bulcroft 1987; Westgarth et al.
2008; Overgaauw et al. 2009). The rate of bed sharing differs according to several factors. These
include, but are not limited to, the type of pet (cats and dogs are the most frequent bed visitors,
with cats the most likely to sleep with the family than any other type; Albert and Bulcroft 1987);
the size of the pet (e.g., most dogs allowed in the bed are smaller breeds; Eckstein 2012); the
number of children in the household (higher for those with no children; Albert and Bulcroft 1987);
and owner characteristics such as gender (more common in females) and ethnicity (higher in
Anglo-Saxon than African American; Brown 2002).
In addition to potential health hazards (see Plaut, Zimmerman and Goldstein 1996), having
pets in the bed/bedroom can lead to behavioral problems displayed by the pet (e.g., Beck
and Katcher 1996; Jagoe and Serpell 1996), disrupt relations between human co-sleepers
The Prevalence and Implications of Human–Animal Co-Sleeping in an Australian Sample
544 Anthrozoös
❖
AZ 27-4.Text_Layout 1 10/13/14 12:54 PM Page 544

(e.g., Jagoe and Serpell 1996), and can represent a significant cause of night-time distur-
bance. For instance, the Mayo Sleep Clinic in the US surveyed 300 patients with an existing
sleep disorder, and found that 53% of pet owners who allowed their pet(s) to sleep in their
bed were disturbed every night by the animal in some way. It is difficult to determine the sig-
nificance of these disruptions, with only 1% of patients feeling that their sleep was disrupted
for more than 20 minutes on average per night (Fayerman 2002). Disruptions may be related
to differences in sleep/wake cycles in companion animals. Dogs are polyphasic sleepers
(which involves multiple rest-activity cycles in a 24-hour period), whereas humans are
monophasic (sleep at night, awake by day; Campbell and Tobler 1984). This is supported by
the findings from Adams and Johnson (1994) who studied the sleep/wake cycles of dogs in
various types of urban backyards. Dogs were found to have an average of 23 sleep/wake
episodes (or 3 sleep/wake cycles per hour), with active sleep followed immediately by spon-
taneous arousal. They also discovered that dogs are responsive to auditory stimuli regardless
of sleep state (quiet and active sleep; Adams and Johnson 1994). Their responses to such
stimuli often led to dogs being a nuisance to people in the neighborhood (e.g., due to bark-
ing) and potentially disrupting the sleep of owners and non-owners alike. The extent to which
human–animal co-sleeping impacts directly upon human sleep has received little attention.
The aim of this study was to determine the prevalence of human–animal co-sleeping in an
Australian sample, and the extent to which such behaviour impacts on the sleep quality/
quantity of the human bed partner.
Methods
The study used data collected from the 2012 Sealy Sleep Census, a national online survey of
sleep wellness conducted by Sealy Australia (a leading manufacturer of beds and mattresses)
in conjunction with the Appleton Institute at Central Queensland University (see www.sealysleep-
census.com.au). The survey consisted of 47 questions, and took approximately 10 minutes to
complete. Questions specific to the current study included gender and age of respondent; typ-
ical sleep length (“How much sleep have you had in the 24 hours prior to answering this
Census?” and “How long did it take you to get to sleep last time you slept for more than
2 hours?”); quality of sleep (“Do you wake up tired?” “Do you find yourself feeling tired during
the day due to poor sleep?”); sleep disturbances (“Do you generally wake up during sleep from
disturbances?” and if so, “Which of the following scenarios causes you to wake up—noisy
neighbours, traffic, dogs barking/animals making noises, children, garbage trucks, rain, house-
mates, other”); sleeping arrangements (“Which of these options best describes your regular
sleep situation?—I sleep alone, I sleep with a partner, My pet(s) sleep on the bed with me, My
child/children sleep in the bed with me, or other”); and any health conditions that may have
affected their sleep (“Do you have any health conditions that affect your sleep?”).
A total of 13,089 people responded to the survey during February and March, 2012. This
was reduced to 10,128 after data cleaning (i.e., those outside the ages of 17–75 years, with
a sleep latency greater than 3 hours, had more than 12 hours sleep in the past 24 hours, or
had more than 24 hours sleep in the past 48 hours were excluded). A total of 2,036 partici-
pants aged between 18 and 74 (256 male, 1780 female) were selected from the pool of
respondents. This included all 1,018 who reported allowing pets to sleep with them in their bed
(128 male, 890 female; 29% aged 18–34; 48% aged 35–54; and 23% aged 55–74). Pet
co-sleepers were directly compared with non-co-sleepers. That is, the participants reporting
co-sleeping with pets were matched from a randomized pool of participants who did not report
Smith
545 Anthrozoös
AZ 27-4.Text_Layout 1 10/13/14 12:54 PM Page 545

co-sleeping with their pets, according to age and gender (thus, the distribution of age and
gender for non-co-sleepers was identical to those who reported co-sleeping with pets).
Results
Data were analyzed to consider the impacts of human–animal co-sleeping on sleep quality.
This paper reports findings on sleeping arrangements, sleep length, sleep onset, tiredness
upon waking, tiredness during the day, sleep disturbances (including dogs barking), and
human health conditions.
Sleeping Arrangements
A total of 1,018 (or 10% of all respondents) reported that they allowed their pet/s to sleep with
them in their bed at night. Of those who allowed pets in their beds, 57% also slept with a part-
ner, 21% slept only with their pet, 6% slept with child/children in the bed as well as their pet,
and 3% with pet, partner, and child.
Sleep Length and Type
An independent samples t-test revealed no significant differences between those who did
(M= 435.65 min, SD = 84.77) and did not (M= 431.80 min, SD = 86.44) co-sleep with pets,
in relation to the amount of sleep gained in the 24 hours prior to completing the questionnaire
(t(2,034) = 1.01, p= 0.311). Further, Cohen’s effect size was small (d= 0.06), suggesting no
practical difference. There was a significant difference in the time taken to get to sleep, with
those that bed-shared with pets (M= 46.72 min, SD = 42.46) taking longer getting to sleep
than those who did not (M= 42.65 min, SD = 41.50) (t(2,034) = 2.19, p= 0.029). However,
Cohen’s effect size for this comparison was also small (d= 0.10; see Figure 1). Moreover, the
wording of the question, “How long did it take you to get to sleep last time you slept for more
than 2 hours?’ did not discern between time taken “trying” to fall asleep and time spent in bed
prior to falling asleep. The former is of the most significance to sleep latency.
Sleep Quality
When asked “Do you wake up tired” respondents were given three choices (often, sometimes,
never). Due to a paucity of “never” responses, responses were reclassified as either “often” or
“sometimes/never.” The unadjusted odds ratios with 95% confidence intervals were calcu-
lated for each of the bed sharing options (alone, partner, pet, child, multiple). As can be seen
The Prevalence and Implications of Human–Animal Co-Sleeping in an Australian Sample
546 Anthrozoös
Figure 1. (a) Mean time taken (minutes) to get to sleep, and (b) the amount of sleep
(minutes) in the past 24 hours for those who did and did not sleep with pets in their
bed. *p< 0.05.
AZ 27-4.Text_Layout 1 10/13/14 12:54 PM Page 546

Smith
547 Anthrozoös
in Table 1, only pet sharers and those sharing the bed with more than one person or pet
reached significance (p< 0.05). A logistic regression analysis was conducted with pet (yes/no),
age (18–34, 35–54, 55–74 years), and gender (male/female) as the predictor variables, and
“wake up tired” (often/sometimes or never) as the dependent variable. This model was sig-
nificant, and is presented in Table 2. All three variables were significant predictors of waking
up tired, with females more likely to report waking up tired than males, younger respondents
more likely to wake up tired than those older, and those who slept with pets more likely to feel
tired upon waking than those who didn’t sleep with pets.
Although those who slept with pets were more likely to feel tired upon waking than those
who did not sleep with pets, they were not more likely to feel tired throughout the day. Only
those who slept with their children and had multiple people or pets in their bed felt tired during
the day (p< 0.05). This is reflected in Table 1.
Participants were also asked, “Do you generally wake up during sleep from disturbances?”
Overall, 72% (1,475/2,036) of respondents reported waking up during the night as the result
of some form of disturbance. As can be seen in Table 1, those who co-slept with their pets
were no more likely to report waking up from sleep disturbances than those who did not sleep
with pets. Again, only those who slept with their children or with multiple people or pets re-
ported being woken up from sleep disturbances.
When prompted for scenarios that caused the disturbances, pet co-sleepers (447
respondents, or 44% of co-sleepers) had a significantly greater chance of being disturbed
by dogs barking/animals making noises than non-co-sleepers (308 respondents, or 30% of
Table 1. Odds ratios for the items “feelings of tiredness upon waking,” “feelings of tiredness dur-
ing the day,” and “waking up from sleep disturbances,” according to co-sleeping arrangements.
Item Sleeping Arrangement
Alone Partner Pet Child Multiple
Do You Wake Up Tired? 0.89 0.95 1.11* 0.98 1.31*
Do You Find Yourself Feeling
Tired during the Day Due
to Poor Sleep? 0.98 0.88 1.11* 2.14* 1.27*
Do You Generally Wake Up
during Sleep from
Disturbances? 0.74 1.10* 1.06* 4.04* 1.32*
*p< 0.05.
Table 2. Logistic regression analysis for feelings of tiredness upon waking according to age,
gender, and co-sleeping with a pet.
Independent Variable
BSE Wald pExp(B)
Co-Sleep with Pet –0.002 0.001 5.057 0.025 0.998
Gender –0.458 0.137 11.107 0.001 0.633
Age 0.446 0.064 49.014 < 0.001 1.562
Note: The dependent variable in this analysis is “wake up tired” (coded 0 = often, 1 = not often).
Model 2= 65.518, p< 0.001; Pseudo R2= 0.042; n= 2,036.
AZ 27-4.Text_Layout 1 10/13/14 12:54 PM Page 547

The Prevalence and Implications of Human–Animal Co-Sleeping in an Australian Sample
548 Anthrozoös
non co-sleepers) (2(1,1475) = 42.533, p< 0.001). No significant differences (p> 0.05) were
found for any other scenario, including noisy neighbors, traffic, garbage trucks, rain,
housemates, or other.
Health Conditions
Thirty-two percent of participants reported having a health condition that affected their sleep
in some way. Those who had a health condition were more likely to sleep with a pet in their
bed (59%) than those who did not (41%). When controlling for health conditions (i.e., remove
those with health condition from the sample), a significant difference between pet (n= 641) and
not-pet sleepers (n= 752) was found for waking up tired as well as for being disturbed by
dogs barking/animals making noises (p< 0.05). No significant difference was found for amount
of sleep obtained in the past 24 hours, time taken getting to sleep, feelings of tiredness during
the day, or waking up during sleep from disturbances (p> 0.05).
Discussion
According to this survey, 1 in 10 Australians co-sleep with at least one pet. This figure does
not account for those that allow pets in the bedroom during the night. It is expected that the
rate of human–animal co-sleeping amongst pet owners is considerably higher than the general
population studied in this questionnaire.
There were three ways in which human sleep practices were impacted by human–animal
co-sleeping. First, there was a significant impact on the time it took pet co-sleepers to get to
sleep (4.07 minutes longer than non-pet co-sleepers, which although statistically significant,
is unlikely to be clinically significant). The reasons for this difference are unclear. Whilst the
presence of pets may have made it more difficult to fall sleep, additional time could have been
used to attain mutually convenient sleeping positions, to interact with the pet, or to settle it be-
fore sleeping. Nonetheless, participants may have valued some of these potential time uses
positively. The sleep latency reported by the total number of respondents (those who slept
with pets and those who did not) was higher than would be expected in a normal adult
population (i.e., 15 minutes; Dement and Vaughan 1999). This apparent over-reporting of sleep
latency across the survey may have resulted from a misunderstanding of the question. That
is, respondents may have reported the time spent in bed prior to falling asleep, rather than the
time taken trying to fall asleep.
Second, human–animal co-sleepers were significantly more likely to wake up tired than
those who did not co-sleep with pets. However, no difference was found when comparing
feelings of sleepiness during the day. The manner in which a person is woken may play a role
in the level of sleepiness experienced upon waking. For example, being woken by a pet be-
fore an alarm or natural wake cycle may contribute to a perceived lack of sleep or feelings of
tiredness or sleep inertia (Tassi and Muzet 2000). This may occur when pets disrupt owners
for attention, toileting, or feeding, and may reflect asynchronous human and animal circadian
rhythms (Campbell and Tobler 1984; Adams and Johnson 1994). Another possibility may be
that pet owners wake earlier in order to exercise their pets before work.
Third, we found that human–animal co-sleepers were more likely to report sleep
disturbances from dogs barking and animal noises. However, as the survey did not distinguish
the source of the animal disturbance, it may not have come directly from the participants’ pets.
For example, animal noises could originate from the participants’ own bedroom, other rooms
in the house, their roof cavities (e.g., possums, a small to medium-sized arboreal marsupial
AZ 27-4.Text_Layout 1 10/13/14 12:54 PM Page 548

species native to Australia), animals in the backyard, or animals in the neighborhood. It is pos-
sible that those who own pets live in neighborhoods with similar animal ownership trends,
leading to increased exposure of pet owners to animal noises. Pet owners may be more sen-
sitized to animal noises or more likely to worry that their own pet may need attention. It follows
that they may be more likely to be disturbed by sounds from their own animals or those in the
broader neighborhood.
Clinical Implications
Our findings have some very relevant implications for clinical practice and sleep research.
Sleep researchers should be aware that at least 10% of their participants may be accustomed
to sleeping with a pet(s) in their bed. As this is a relatively common practice that may have neg-
ative effects on sleep, sleep researchers should take into account human–animal co-sleeping
when collecting patient sleep history and behavior (four demographic questions are suggested
below). Moreover, researchers collecting data on sleep disturbances should consider
delineating various sources of animal noises.
People staying overnight in clinical settings (such as hospitals) may experience some
distress at leaving their pet at home or with a friend or family member. Similarly, clinicians
should be aware of, and sympathetic to, pet owners’ desires to co-sleep with animals when
providing recommendations for sleep hygiene. For patients who allow pets in the bed and are
experiencing sleep problems, it may be recommended that the pet be relocated to another
room. As human–animal co-sleepers are unlikely to alter their behavior, incremental behavior
change strategies may be most appropriate, such as allowing pets to sleep in the same room
rather than in or on the bed. In such cases, a multidisciplinary approach may be required
whereby medical professions (e.g., medical doctors and psychologists) can support human
behavior change whilst veterinarians or others trained in animal behavior may be able to assist
with changing the pet’s nocturnal behavior, in an effort to limit disturbances or negative health
effects associated with human–animal co-sleeping.
Limitations and Directions for Future Research
This survey used a non-representative sample, was not pet specific, and our use of pet re-
lated data was post-hoc and opportunistic. Therefore the survey was not able to distinguish
between pet owners and non-pet owners. In relation to sleeping arrangements, neither did
the survey determine the age of the children co-sleepers, how bed-sharers were occupied
in the time spent in bed prior to sleep, how this time-use was valued, the exact impact of a
pet on sleep onset latency, the type of pet that each participant slept with, the number of
animals on the bed, the location of the pet (in the bed or bedroom), or the consistency of
the reported human–animal co-sleeping practices (they may change when a child is pres-
ent in the home, for example). In relation to sleep disturbances, the survey did not discern
the sources of animal noises. This information seems important, given trends toward in-
creased urban density, alongside a greater recognition of the social, mental, and physical
benefits of pet ownership (Smith 2012). Future studies should determine causes of sleep dis-
turbances within the bedroom, and ascertain, for example, whether humans (adult or child),
cause more disturbances than pets when in the same sleeping space. In addition, the self-
selected sample used is likely biased toward people who were experiencing sleep
disturbances, as they had a high incidence of sleep disruption compared with the normal
population. Also, given that participants in our survey were 18 years of age and over, the
impact of human–animal co-sleeping behaviors on younger pet co-sleepers also remains
Smith
549 Anthrozoös
AZ 27-4.Text_Layout 1 10/13/14 12:54 PM Page 549

unknown. To gain an accurate representation of the Australian population, a stratified,
matched sample is required.
To address these shortcomings and more comprehensively understand human–animal
co-sleeping practices and their impacts, there is a need for a dedicated and comprehensive
survey of human–animal co-sleeping practices. Such a survey tool should include questions
designed to provide greater understanding of the sleeping arrangements and disturbances
as listed above. However, as a minimum data set, we recommend that the following four
demographic questions be included in basic sleep research as well as research on human–
animal co-sleeping: 1) Do you own a pet? 2) Do you co-sleep with your pet? 3) Where in the
room is your pet (on floor, on bed, in bed)? and 4) Can your pet toilet independently? (i.e., can
it let itself in and out of the room for toileting without waking the respondent.) Animal attach-
ment scales may also be included, as the concept of attachment is based on the assumption
that anxiety is experienced in the absence of the attachment figure.
Acknowledgements
The authors thank Sealy Cooperation Australia for supporting the project, as well as the public
who took the time to complete the survey. Thanks also to the editor and two anonymous
reviewers for their helpful comments on earlier versions of the manuscript.
References
Adams, G. and Johnson, K. 1994. Behavioural responses to barking and other auditory stimuli during night-time
sleeping and waking in the domestic dog (Canis familiaris). Applied Animal Behaviour Science 39: 151–162.
Albert, A. and Bulcroft, K. 1987. Pets and urban life. Anthrozoös 1: 9–25.
American Pet Product Manufacturer Association (APPMA). 2013. 20013/2014 APPMA National Pet Owners
Survey. Greenwich, CT: APPMA.
Archer, J. 1997. Why do people love their pets? Evolution and Human Behavior 18: 237–259.
Australian Bureau of Statistics. 1995. Australian Social Trends 1995. Canberra, Australia: Australian Bureau of
Statistics.
Australian Companion Animal Council. 2010. Contribution of the pet care industry to the Australian Economy.
7th edn. http://www.acac.org.au/pdf/ACAC%20Report%200810_sm.pdf. Accessed on September 5, 2013
Beck, A. and Katcher, A. 1996. Between Pets and People: The Importance of Animal Companionship. West
Lafayette, IN: Purdue University Press.
Breckwoldt, R. 1988. A Very Elegant Animal: The Dingo. North Ryde, Australia: Angus and Robertson Publishers.
Brown S. 2002. Ethnic variations in pet attachment among students at an American school of veterinary
medicine. Society & Animals 10: 249–266.
Brown, S. E. 2007. Companion animals as selfobjects. Anthrozoös 20: 329–343.
Campbell, S. and Tobler, I. 1984. Animal sleep: A review of sleep duration across the phylogeny. Neuroscience
and Behavioral Reviews 8: 269–300.
Dement, W. and Vaughan, C. 1999. The Promise of Sleep: A Pioneer in Sleep Medicine Explores the Vital
Connection between Health, Happiness, and a Good Night’s Sleep. New York: Dell Trade Paperbacks.
Eckstein, S. 2012. Pets in your bed. http://pets.webmd.com/features/pets-in-your-bed. Accessed on
September 5, 2013.
Fayerman, P. 2002. Pet’s love outweighs other factors for owners. North Bay Nugget, March 2.
Franklin, A. 2006. Animal Nation: The True Story of Animals and Australia. Sydney: UNSW Press.
Jagoe, J. A. and Serpell, J. 1996. Owner characteristics and interactions and the prevalence of canine behaviour
problems. Applied Animal Behaviour Science 47: 31–42.
Katcher, A., Friedmann, E., Goodman, M. and Goodman, L. 1983. Men, women, and dogs. Californian
Veterinarian 2: 14–16.
The Prevalence and Implications of Human–Animal Co-Sleeping in an Australian Sample
550 Anthrozoös
AZ 27-4.Text_Layout 1 10/13/14 12:54 PM Page 550

Overgaauw, P., van Zutphen, L., Hoek, D., Yaya, F., Roelfsema, J., Pinelli, E., van Knapen, F. and Kortbeek, L.
2009. Zoonotic parasites in fecal samples and fur from dogs and cats in The Netherlands. Vet Parasitology
163: 115–122.
Plaut, M., Zimmerman, E. and Goldstein, R. 1996. Health hazards to humans associated with domestic pets.
Annual Review of Public Health 17: 221–245.
Serpell, J. A. 1989. Pet-keeping and animal domestication: A reappraisal. In The Walking Larder: Patterns of
Domestication, Pastorialism and Predation, 11–21, ed. J. Clutton-Brock. London: Unwin Hyman.
Smith, B. 2012. “The pet effect”: Health related aspects of companion animal ownership. Australian Family
Physician 41: 439–442.
Smith, B. and Litchfield, C. 2009. A review of the relationship between Indigenous Australians, dingoes (Canis
dingo) and domestic dogs (Canis familiaris). Anthrozoös 22: 111–128.
Tassi, P. and Muzet, A. 2000. Sleep inertia. Sleep Medicine Reviews 4: 341–353.
Westgarth, C., Pinchbeck, G., Bradshaw, J., Dawson, S., Gaskell, R. and Christley, R. 2008. Dog–human and
dog–dog interactions of 260 dog-owning households in a community in Cheshire. Veterinary Record 162:
436–442.
Smith
551 Anthrozoös
AZ 27-4.Text_Layout 1 10/13/14 12:54 PM Page 551