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Associations between the
Psychological Characteristics
of the Human–Dog
Relationship and Oxytocin
and Cortisol Levels
Linda Handlin*†, Anne Nilsson*†, Mikael Ejdebäck*,
Eva Hydbring-Sandberg‡and Kerstin Uvnäs-Moberg*†
*Systems Biology Research Centre, University of Skövde, Sweden
†Department of Animal Environment and Health, Swedish University
of Agricultural Sciences, Skara, Sweden
‡Department of Anatomy, Physiology, and Biochemistry, Swedish
University of Agricultural Sciences, Uppsala, Sweden
ABSTRACT The aim of the present study was to explore possible correlations
between dog owners’ relationships with their dogs, as measured with the
Monash Dog Owner Relationship Scale (MDORS), and oxytocin and cortisol
levels in both the owners and their dogs. Ten female owners of male Labrador
Retrievers completed the MDORS. The scores obtained from the single items,
subscales, and total score of the MDORS were calculated. Ten blood sam-
ples were collected from each dog owner and her dog during a 60-minute
interaction. Blood samples were analyzed for oxytocin and cortisol by Enzyme
Immuno Assay (EIA) and mean values of oxytocin and cortisol were calcu-
lated in both owners and dogs. The MDORS scores obtained were correlated
with basal and mean oxytocin and cortisol levels. The correlation analysis
revealed some relationships between the scores of items in the MDORS that
reflect the character of the dog–owner-relationship and the owners’ hormone
levels. For example, higher oxytocin levels in the owners were associated with
greater frequency in kissing their dogs (rs= 0.864, p= 0.001). Lower cortisol
levels in the owners were associated with their perception that it will be more
traumatic when their dog dies (rs= –0.730, p= 0.025). The correlation analy-
sis also revealed some relationships between the scores of items in the
MDORS and the dogs’ hormone levels. For example, greater frequency in
owners kissing their dogs was associated with higher oxytocin levels in the
dogs (rs= 0.753, p= 0.029). Six items in the subscale Perceived Costs, as
well as the subscale itself, correlated significantly with the dogs’ oxytocin levels
(rs= 0.820, p= 0.007), that is, the lower the perceived cost, the higher the
215 Anthrozoös DOI: 10.2752/175303712X13316289505468
ANTHROZOÖS VOLUME 25, ISSUE 2 REPRINTS AVAILABLE PHOTOCOPYING © ISAZ 2012
PP. 215–228 DIRECTLY FROM PERMITTED PRINTED IN THE UK
THE PUBLISHERS BY LICENSE ONLY
Address for correspondence:
Linda Handlin,
Systems Biology Research
Centre, University of Skövde,
Box 408, SE-541 28,
Skövde, Sweden.
E-mail: linda.handlin@his.se
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dogs’ oxytocin levels. In addition, significant correlations between the oxytocin levels of the owners
and the dogs were demonstrated. Possible mechanisms behind these correlations are discussed.
In conclusion, the scores of some items and the subscales of the MDORS correlated with oxytocin,
and to a lesser extent cortisol, levels in both the owners and dogs.
Keywords: cortisol, dog, dog owner, MDORS, oxytocin
The relationship between humans and animals, especially between humans and their
companion dogs, can be a close emotional connection. Dogs often have the status
of family members and are frequently described by owners as a source of emotional
support (Walsh 2009).
Attachment, according to Bowlby and Ainsworth (Bowlby 1969; Bowlby 1973; Bowlby
1980; Ainsworth 1989), is a description of the relationship between a child and his/her mother.
Bonding, on the other hand, is used to describe the positive interaction between mothers and
their infants (Kennell and Klaus 1998). Both types of relationships are characterized by positive
emotions in the sense that both individuals experience pleasure and security in the presence
of each other, and anxiety and distress when separated. Lately, it has been suggested that the
relationship between a dog owner and his/her dog might represent expressions of attach-
ment/bonding (Topal et al. 1998; Prato-Previde, Spiezio and Sabatini 2003; Palmer and
Custance 2008).
The neuropeptide oxytocin plays an important role in bonding and attachment between
mother and young in all mammalian species, as well as other types of relationships such as
in pair bonding (Carter 1998; Insel et al. 1998; Uvnäs-Moberg, Arn and Magnusson 2005).
Oxytocin is produced in the supraoptic nucleus (SON) and paraventricular nucleus (PVN) of the
hypothalamus and was originally described as a hormone released into the circulation during
labor and suckling (Richard, Moos and Freund-Mercier 1991). However, oxytocin neurons
from the PVN also project to important regulatory areas within the brain.
Animal studies have shown that administration of oxytocin induces different types of so-
cial behavior, including maternal behavior, bonding between mother and young, and pair bond-
ing (Carter 1998; Insel et al. 1998). In addition, oxytocin induces anxiolytic-like, pain relieving
and sedative effects (Uvnäs-Moberg et al. 1994; Amico et al. 2004); decreases cortisol levels
(Petersson, Hulting and Uvnäs-Moberg 1999) and blood pressure (Petersson et al. 1996;
Holst, Uvnäs-Moberg and Petersson 2002); and influences the release of gastrointestinal
hormones (Petersson et al. 1999). Some of these effects have been shown to be sustained
for several weeks, even months, after repeated administration of oxytocin (Uvnäs-Moberg
1998; Uvnäs-Moberg and Petersson 2010).
Similar effects as those seen in animals have also been demonstrated in humans following
the administration of oxytocin as a nasal spray. Oxytocin has been shown to increase social
skills, decrease anxiety and stress, and increase trust (Heinrichs et al. 2003; Kosfeld et al. 2005).
The same effects seen in both animals and humans after the administration of oxytocin can
also be seen after endogenous oxytocin release in response to non-noxious stimulation, such
as massage, skin-to-skin contact, breastfeeding, and after positive social interactions (Uvnäs-
Moberg and Petersson 2010). For example, rats exposed to stimulation of the sciatic nerve
or gentle stroking (massage) display increased oxytocin levels (Stock and Uvnäs-Moberg
1988), increased pain thresholds (Lund et al. 2002), decreased pulse and blood pressure
(Lund et al. 1999; Holst, Uvnäs-Moberg and Petersson 2002), and decreased cortisol levels
(Tsuchiya, Nakayama and Sato 1991).
❖
Associations between the Psychological Characteristics…
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Handlin et al.
217 Anthrozoös
In addition, mothers who are breastfeeding or having skin-to-skin contact with their infants
display increased oxytocin levels (Nissen et al. 1996; Matthiesen et al. 2001; Jonas et al. 2009)
and decreased cortisol levels and blood pressure (Liu et al. 1997; Jonas et al. 2008a; Handlin
et al. 2009). They also become less anxious, calmer, and more inclined to social interactions
(Uvnäs-Moberg 1996; Nissen et al. 1998; Jonas et al. 2008b). A similar effect was also
observed in infants (Christensson et al. 1995; Bystrova et al. 2003; Jonas et al. 2007).
In breastfeeding mothers, the oxytocin effects are induced as an acute response to the actual
interaction; but in response to the repeated interaction, and hence repeated exposure to oxy-
tocin, these effects are also transformed into long-term effects. In addition, individual mothers
have their own oxytocin levels, and mothers with higher basal oxytocin levels are more interactive
with their children and more sensitive to their children’s cues (Feldman et al. 2007).
Interaction between humans and dogs is followed by a release of oxytocin in both species
and also by reduced cortisol levels and blood pressure (Odendaal and Meintjes 2003; Miller et
al. 2009; Handlin et al. 2011). It is not known, however, whether the type of relationship a dog
owner has with his/her dog is reflected in endocrine parameters. Owners with high oxytocin lev-
els may hypothetically have a more caring and interactive character or personality and therefore
a more positive attitude towards their dogs, just as mothers with high oxytocin levels are more
interactive and sensitive to their infants’ needs (Feldman et al. 2007). It is also possible that dogs
with high oxytocin levels may be more interactive and more sensitive to their owners’ physiological
and mental status. Alternatively, the interaction between the dog and its owner may induce long-
term, secondary endocrine changes, resulting in increased oxytocin levels.
Since oxytocin is released in response to each positive interaction between a dog and its
owner, and since repeated administration of oxytocin can induce long-term, anti-stress ef-
fects, a long lasting relationship involving repeated close interaction between owners and dogs
might give rise to a reduction in blood pressure and cortisol levels. In fact, interaction between
dog owners and dogs has been shown to result in lower cortisol levels for the dogs. Further-
more, dogs with highly interactive owners have low cortisol levels in comparison with those with
less interactive owners (Kotrschal et al. 2009).
The quality and type of relationship between dog owners and their companion dogs can
be evaluated by inventories such as the Monash Dog Owner Relationship Scale (MDORS),
which concerns both positive and negative aspects of the relationship with a companion dog.
In the present study, we wanted to investigate whether there are associations between
the quality of the relationship between a dog and its owner and the oxytocin and cortisol lev-
els in both owners and dogs. Ten female dog owners completed the 28-item MDORS ques-
tionnaire, and blood samples from both the owners and the dogs were collected. The answers
from the MDORS questionnaire were then correlated with the owners’ as well as the dogs’
oxytocin and cortisol levels.
Methods
Participants
The study was conducted at the Swedish University of Agricultural Sciences in Skara, Sweden.
Through information gathered at local workplaces and local veterinarian clinics, the prospec-
tive participants were informed of the study and the experimental design. As a result, ten
privately owned male Labrador Retrievers and their female owners were recruited to the study.
Eligible participants were middle-aged women (35–70 years) who owned a male Labrador
older than 1 year, where both owner and dog did not have any current documented illnesses.
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The mean age of the owners was 53 years (SD = 10) and the mean age of the dogs was 4.7
years (SD = 3).
Before the experiment started, the owners were informed about the study; they were given
the opportunity to ask any questions regarding the experiment, and were informed that they
could end their participation at any time. The owners then signed an informed consent form
to participate in the study. The experimental procedure for the human participants was
approved by the Local Ethics Committee in Uppsala, and the procedure for the dogs was ap-
proved by the Animal Ethics Committee in Uppsala. The use of privately owned dogs was
approved by the National Board of Agriculture.
MDORS
The Monash Dog Owner Relationship Scale (MDORS) was developed by Dwyer, Bennett and
Coleman in 2006 to assess the perceived relationship between dog owners and their com-
panion dogs. The scale consists of 28 items where the dog owner selects one of five possi-
ble responses, labeled 1 to 5 for each item, with 1 representing the lowest frequency or the
least positive response and 5 representing the highest frequency or the most positive re-
sponse. The items can then be further arranged into sub-scales. The subscale Dog–Owner
Interaction reflects both general activities related to the care of the dog and more intimate ac-
tivities; this subscale indicates the amount of time spent together as well as the opportunity
for shared emotional experiences and reciprocal interactions. The subscale Perceived
Emotional Closeness contains items relating to social support, affectional bonding, psycho-
logical attachment, companionship, and unconditional love. The subscale Perceived Costs
addresses the cost of caring for a companion dog; this subscale includes the monetary as-
pects and increased responsibility and restrictions placed on the owner because of the dog
(Dwyer, Bennett and Coleman 2006). The MDORS score has no absolute value, so what con-
stitutes an average, high, or low score is not known and probably varies depending on the type
of dogs and groups of humans investigated.
In the present study, the item “My dog gives me a reason to get up in the morning” was
excluded because some owners interpreted it as a positive statement, while others interpreted
it as a negative statement. For a similar reason, the item “There are major aspects of owning
a dog I don’t like” was also excluded due to owners’ different interpretations of the item as ei-
ther a positive or a negative statement. The item “How often do you take your dog in the car?”
was excluded because not all dog owners had a car. Therefore these three items were not in-
cluded in the summarized scores for the different subscales or in the total score of the MDORS.
Experimental Setup
The owner and her dog arrived together at the testing facility. The experiment was performed
in a room located on the second floor of one of the buildings in the university campus. It was
an ordinary room, designed to look like a regular living room with a desk, four chairs, a book
case, and a water bowl for the dog. Both the owner and the dog had a cannula inserted for
blood sampling before the experiment started, according to the procedure described by
Handlin et al. (2011).
The Interaction Experiment and MDORS
The owner sat in a chair during the entire experiment while the dog was let loose (i.e., off-
leash), sitting or lying beside her. At time point zero, the owner sat in close contact with her
dog and started to pet and stroke different parts of the dog’s body and talked to the dog for
218 Anthrozoös
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three minutes. After three minutes of interaction, the owner remained seated in her chair and
did not touch the dog for the rest of the experiment, which lasted 60 minutes. The whole
experiment was videotaped.
Blood samples were collected simultaneously from both owner and dog at 0, 1, 3, 5, 15,
30, and 60 minutes after the start of interaction. According to the analysis of the video record-
ings, the dogs did not experience the collection of blood samples as stressful (data not shown)
and the impact of the blood sampling appeared minimal.
If the dog attempted to interact with the owner during the remaining time of the experiment,
the owner was instructed to ignore the dog. This resulted in the dog immediately stopping its
attempt for contact. Verbal communication between the owner and the other people present
in the room was allowed during the whole experiment.
During the last 30 minutes of the experiment, the owners completed the MDORS, with the
dog still in the room. The MDORS had previously been translated into Swedish from Dwyer,
Bennett and Coleman’s original English version (2006).
Only one dog–owner pair performed the experiment at a time. In addition to the owner and
the dog, four other persons were present in the room during the entire experiment: one ani-
mal caretaker, one nurse, one person preparing the blood samples for hormone analysis, and
one person videotaping the experiment. The animal caretaker and the nurse were in contact
with the dog or owner during cannula insertion and blood sampling. None of the other persons
were in physical contact with either the dog or the owner during the experiment.
Hormonal Analysis
Oxytocin and cortisol levels from both owners and dogs were analyzed by enzyme
immunoassay, as described by Handlin et al. (2011).
Statistical Analysis
The data were analyzed using the Statistical Package for the Social Sciences (SPSS/PASW)
software, version 18.0 (Chicago, IL, USA).The mean scores and standard deviations were
calculated for each item in the MDORS. The items were then arranged into subscales, as pro-
posed by Dwyer, Bennett and Coleman (2006), and the mean score and standard deviation
for each subscale, as well as the total mean score, were also calculated for each owner. The
three excluded items were not included in any of the calculations.
For each hormone and participant, mean values with corresponding SD based on all sam-
ples collected during the experiment (0–60 minutes) were calculated. The non-parametric
Spearman rank coefficient was used to calculate correlations because the number of partici–
pants in the present study was relatively small and a normal distribution of data could not be
assumed. Correlations were calculated between MDORS scores and the mean and basal lev-
els of the owners’ and the dogs’ oxytocin and cortisol levels. Correlations were also calculated
between the owners’ and the dogs’ oxytocin and cortisol levels at each individual time point
of the interaction experiment. The statistical significance level was set at p< 0.05.
Results
MDORS
Owners’ itemized scores of single items, the subscales, and the total MDORS score are sum-
marized in Table 1. The scores of the three subscales, Dog–Owner Interaction (DOI), Emotional
Closeness (EC), and Perceived Costs (PC), were 4.1 (SD = 0.4), 3.8 (SD = 0.4), and 3.8
(SD = 0.4), respectively, and the mean total MDORS score was 4.0 (SD = 0.4).
219 Anthrozoös
Handlin et al.
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Table 1. The scores of the single items, subscales, and total MDORS score are presented as
mean values (SD).
Items/Subscales Answering Alternatives Mean Score
1) How hard is it to look after 1 = very easy, 2 = easy, 3 = neither hard nor easy, 4 = hard, 1.8 (0.8)
your dog? (PC) 5 = very hard
2) My dog gives me a reason Excluded due to the owners’ different interpretations —
to get up in the morning. (EC) of the item as either a positive or a negative statement
3) There are major aspects of Excluded due to the owners’ different interpretations of the —
owning a dog I don’t like. (PC) item as either a positive or a negative statement
4) How often do you kiss your 1 = never, 2 = once a month, 3 = once a week, 4 = once 4.1 (1.4)
dog? (DOI) every few days, 5 = at least once a day
5) I wish my dog and I never 1 = strongly disagree, 2 = disagree, 3 = neither agree nor 3.3 (1.2)
had to be apart. (EC) disagree, 4 = agree, 5 = strongly agree
6) My dog makes too much 1 = strongly disagree, 2 = disagree, 3 = neither agree nor 1.9 (1.0)
mess. (PC) disagree, 4 = agree, 5 = strongly agree
7) How often do you play 1 = never, 2 = once a month, 3 = once a week, 4 = once every 4.4 (1.0)
games with your dog? (DOI) few days, 5 = at least once a day
8) It bothers me that my dog 1 = strongly disagree, 2 = disagree, 3 = neither agree nor 1.5 (0.5)
stops me from doing things I disagree, 4 = agree, 5 = strongly agree
enjoyed before I owned it. (PC)
9) How often do you take your 1 = never, 2 = few times each year, 3 = once a month, 4.3 (0.9)
dog to visit people? (DOI) 4 = once a fortnight, 5 = once a week
10) It is annoying that I 1 = strongly disagree , 2 = disagree, 3 = neither agree nor 2.0 (0.9)
sometimes have to change my disagree, 4 = agree, 5 = strongly agree
plans because of my dog. (PC)
11) My dog costs too much 1= strongly disagree , 2 = disagree , 3 = neither agree nor 1.6 (0.7)
money. (PC) disagree, 4 = agree, 5 = strongly agree
12) How often do you buy your 1 = never , 2 = few times each year , 3 = once a month, 3.2 (1.1)
dog presents? (DOI) 4 = once a fortnight, 5 = once a week
13) My dog is constantly 1 = strongly disagree, 2 = disagree, 3 = neither agree nor 3.9 (0.9)
attentive to me. (EC) disagree, 4 = agree, 5 = strongly agree
14) How often do you give your 1 = never, 2 = once a month, 3 = once a week, 4 = once every 4.2 (0.6)
dog food treats? (DOI) few days, 5 = at least once a day
15) How often do you tell your 1 = never, 2 = once a year, 3 = once a month, 4 = once a week, 2.7 (0.9)
dog things you don’t tell anyone 5 = once a day
else? (EC)
16) How often do you feel that 1 = never, 2 = once a year, 3 = once a month, 4 = once a week, 1.6 (1.1)
looking after your dog is a 5 = once a day
chore? (PC)
17) How often do you take your Excluded since not all dog owners had a car —
dog in the car? (DOI)
18) How often does your dog 1 = never, 2 = once a year, 3 = once a month, 4 = once a week, 1.8 (0.8)
stop you from doing things you 5 = once a day
want to? (PC)
19) I would like to have my dog 1 = strongly disagree, 2 = disagree, 3 = neither agree nor 3.3 (1.2)
near me all the time. (EC) disagree, 4 = agree, 5 = strongly agree
20) How often do you groom 1 = never, 2 = once a month, 3 = once a week, 4 = once every 2.4 (0.7)
your dog? (DOI) few days, 5 = at least once a day
21) If everyone else left me, my 1 = strongly disagree, 2 = disagree, 3 = neither agree nor 4.4 (1.0)
dog would still be there for me. disagree, 4 = agree, 5 = strongly agree
(EC)
Associations between the Psychological Characteristics…
220 Anthrozoös
AZ VOL. 25(2).qxp:Layout 1 3/30/12 10:15 AM Page 220
Items/Subscales Answering Alternatives Mean Score
22) How often do you feel that 1 = never, 2 = once a year, 3 = once a month, 4 = once a week, 1.4 (1.0)
having a dog is more trouble 5 = once a day
than it is worth? (PC)
23) My dog helps me get 1 = strongly agree, 2 = disagree, 3 = neither agree nor 4.3 (0.7)
through tough times. (EC) disagree, 4 = agree, 5 = strongly agree
24) How often do you hug 1 = never, 2 = once a month, 3 = once a week, 4 = once 4.9 (0.3)
your dog? (DOI) every few days, 5 = at least once a day
25) My dog provides me with 1 = strongly disagree, 2 = disagree, 3 = neither agree nor 4.6 (0.7)
constant companionship. (EC) disagree, 4 = agree, 5 = strongly agree
26) How often do you have your 1= never, 2 = once a month, 3 = once a week, 4 = once 4.9 (0.3)
dog with you while relaxing, i.e., every few days, 5 = at least once a day
watching TV? (DOI)
27) My dog is there whenever 1 = strongly disagree, 2 = disagree, 3 = neither agree nor 4.5 (0.7)
I need to be comforted. (EC) disagree, 4 = agree, 5 = strongly agree
28) How traumatic do you 1= not traumatic at all, 2 = not traumatic, 3 = neither traumatic 4.7 (0.5)
think it will be for you when nor not traumatic, 4 = traumatic, 5 = very traumatic
your dog dies? (EC)
Dog–Owner Interaction 1 = less interaction … 5 = much interaction 4.1 (0.4)
Emotional Closeness 1 = less emotional closeness … 5 = strong emotional
closeness 3.8 (0.4)
Perceived Costs 1 = high perceived cost … 5 = low perceived cost 3.8 (0.4)
Total 1 = less positive relationship … 5 = very positive relationship 4.0 (0.4)
DOI: Dog–Owner Interaction subscale.
EC: Perceived Emotional Closeness subscale.
PC: Perceived Costs subscale.
Table 2. Mean hormone concentrations (SD) by time for owners and dogs dyads (n= 10).
0 min 1 min 3 min 5 min 15 min 30 min 60 min Mean
Oxytocin Levels (pmol/l)
Dogs 155.8 211.2 236.9 178.6 163.5 157.5 157.5 180.0
(80.8) (92.0) (116.1) (88.7) (103.4) (108.0) (123.3) (102.1)
Owners 168.5 169.8 180.6 170.2 146.4 171.3 165.1 170.0
(109.5) (107.8) (108.8) (88.1) (104.2) (108.3) (83.2) (97.4)
Cortisol Levels (nmol/l)
Dogs 168.4 169.4 168.1 180.1 224.1 202.8 190.2 186.0
(46.8) (50.9) (48.3) (56.3) (102.7) (58.0) (59.4) (63.3)
Owners 389.8 382.7 382.7 387.6 362.1 331.6 305.2 363.0
(378.4) (339.7) (347.5) (378.1) (341.3) (253.2) (197.9) (312.2)
Handlin et al.
221 Anthrozoös
In response to some of the items, almost all owners gave a maximal score. This resulted
in mean scores of almost 5. Due to the lack of spread, the scores of these items did not allow
for correlation analysis (for details, see Table 1).
Owners’ and Dogs’ Oxytocin and Cortisol Levels
Data on the owners’ and dogs’ oxytocin and cortisol levels have been described previously
(Handlin et al. 2011) but are summarized in Table 2.
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Associations between the Psychological Characteristics…
222 Anthrozoös
Correlations between the Owners’ MDORS Scores and Their Oxytocin and
Cortisol Levels
There was a significant correlation between the owners’ oxytocin levels and how often the
owners kissed their dogs (rs= 0.864, p= 0.001), that is, more frequent kissing was associated
with higher oxytocin levels in the owners. In addition, there was a tendency towards a
significant negative correlation between the owners’ oxytocin levels and how difficult the
owners thought it was to look after their dogs (rs= –0.571, p= 0.085).
Significant correlations were also observed between the scores of some items of the
MDORS and the owners’ cortisol levels. Lower cortisol levels in the owners were related to the
following: being less bothered about their dog stopping them from doing things, increased fre-
quency in bringing their dogs to visit people, and the increased perception of trauma in the
event that the dog dies (rs= 0.661, p= 0.037; rs= –0.645, p= 0.044; and rs= –0.730,
p= 0.025, respectively) (Table 3).
Correlations between the Owners’ MDORS Scores and the Dogs’ Oxytocin and
Cortisol Levels
The dogs’ mean oxytocin levels correlated significantly with three items indicating the inten-
sity of the dog–owner relationship. The higher the dogs’ oxytocin levels, the greater the fre-
quency of owners kissing their dogs, the lower the frequency in giving food treats to their dog,
and the stronger was the perceived bond with the dog (rs= 0.753, p= 0.019; rs= –0.757,
p= 0.018; and rs= 0.708, p= 0.033, respectively) (Table 3).
In addition, significant negative correlations and tendencies towards significant correla-
tions were observed between scores obtained in several items of the Perceived Costs sub-
scale and the dogs’ oxytocin levels. Higher oxytocin levels in the dogs were associated with
the owners having a perception of the dog being less difficult to look after and less thought of
as making a mess (rs= –0.846, p= 0.004 and rs= –0.763, p= 0.017, respectively). In addi-
tion, higher oxytocin levels in the dogs were associated with the owners having a perception
of becoming less annoyed that they sometimes had to change plans because of their dog, a
lower frequency among the owners in feeling that looking after their dog was a chore, and a
perception of there being less trouble in having a dog (rs= –0.647, p= 0.059; rs= –0.614,
p= 0.079; and rs= –0.639, p= 0.064, respectively) (Table 3). One item in the PC subscale also
correlated significantly with the dogs’ mean cortisol levels (r= –0.701, p= 0.024): higher
cortisol levels in the dogs were associated with greater perception in owners that there was
less trouble in having a dog (Table 3).
The dogs’ mean oxytocin levels also correlated significantly with the entire PC subscale
(rs= –0.820, p= 0.007) and, additionally, the dogs’ mean oxytocin levels correlated significantly
with the mean total MDORS score (rs= 0.753, p= 0.019), that is, the higher the dogs’ oxy-
tocin levels, the lower the owners’ perceived cost, and the higher the mean total score. This
indicates a more positive evaluation of the relationship in total (Table 4).
Correlations between the Dog Owners’ and the Dogs’ Hormone Levels
The owners’ mean oxytocin levels at each time point (0, 1, 3, 5, 15, 30, and 60 minutes) and
their mean oxytocin level between 0 and 60 minutes correlated positively, some of which were
statistically significant, with the mean oxytocin level of the dogs at 60 minutes. The higher the
owners’ oxytocin levels were during the interaction experiment, the higher the dogs’ oxytocin
levels were at the end of the experiment (for rs- and p-values, see Table 5). In addition, there
was a significant positive correlation between the dogs’ and the owners’ oxytocin levels at 15
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Table 3. Correlations of single item scores from the MDORS with owner and dog hormone
levels. Only significant correlations (p< 0.05) and those that tended towards significance
(p< 0.10) are shown.
Items Owners’ Owners’ Owners’ Dogs’ Dogs’
Mean Mean Basal Mean Mean
Oxytocin Cortisol Cortisol Oxytocin Cortisol
(pmol/l) (nmol/l) (nmol/l) (pmol/l) (nmol/l)
Dog–Owner Interaction
4) How often do you kiss your dog? rs= 0.864 ns ns rs= 0.753 ns
p= 0.001 p= 0.019
9) How often do you take your dog ns ns r= –0.645 ns ns
to visit people? p= 0.044
14) How often do you give your dog ns ns ns rs= –0.757 ns
food treats? p= 0.018
Emotional Closeness
21) If everyone else left me, my dog ns ns ns rs= 0.708 ns
would still be there for me. p= 0.033
28) How traumatic do you think it will ns r= –0.730 ns ns ns
be for you when your dog dies? p= 0.025
Perceived Costs
1) How hard is it to look after rs= –0.571 ns ns rs= –0.846 ns
your dog? p= 0.085 p= 0.004
6) My dog makes too much mess. ns ns ns rs= –0.763 ns
p= 0.017
8) It bothers me that my dog stops ns ns rs= 0.661 ns ns
me from doing things I enjoyed before p= 0.037
I owned it.
10) It is annoying that I sometimes have ns ns ns rs= –0.647 ns
to change my plans because of my dog. p= 0.059
16) How often do you feel that looking
after your dog is a chore? ns ns ns rs= –0.614 ns
p= 0.079
22) How often do you feel that having a
dog is more trouble than it is worth? ns ns ns rs= –0.639 rs= –0.701
p= 0.064 p= 0.024
Perceived Costs Total Score ns ns ns rs= –0.820 ns
p= 0.007
Total MDORS Score ns ns ns rs= 0.753 ns
p= 0.019
ns = non significant.
Handlin et al.
223 Anthrozoös
minutes (rs= 0.857, p= 0.007) (Table 5). No significant correlations were found between the
owners’ and the dogs’ cortisol levels.
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224 Anthrozoös
Associations between the Psychological Characteristics…
Table 4. Correlations of subscales and total MDORS scores with owner and dog hormone
levels. Significant correlations (p< 0.05) are in bold.
Subscale Owners’ Owners’ Owners’ Dogs’ Dogs’
Mean Mean Basal Mean Mean
Oxytocin Cortisol Cortisol Oxytocin Cortisol
(pmol/l) (nmol/l) (nmol/l) (pmol/l) (nmol/l)
Dog–Owner Interaction rs= 0.299 rs= –0.218 rs= –0.195 rs= –0.135 rs= –0.135
p= 0.402 p= 0.572 p= 0.589 p= 0.729 p= 0.711
Emotional Closeness rs= 0.391 rs= –0.035 rs= 0.130 rs= 0.519 rs= –0.391
p= 0.263 p= 0.930 p= 0.719 p= 0.152 p= 0.263
Perceived Costs rs= 0.238 rs= –0.301 rs= –0.341 rs= 0.820 rs= 0.177
p= 0.508 p= 0.431 p= 0.334 p= 0.007 p= 0.625
Total MDORS Score rs= 0.472 rs= –0.356 rs= –0.313 rs= 0.753 rs= –0.092
p= 0.168 p= 0.347 p= 0.379 p= 0.019 p= 0.800
Table 5. Significant correlations (p< 0.05) between the owners’ and the dogs’ oxytocin levels
during the interaction experiment.
Owners’ Oxytocin Levels at Dogs’ Oxytocin Levels at rsp
0 min 60 min 0.733 0.025
1 min 60 min 0.800 0.010
3 min 60 min 0.683 0.042
5 min 60 min 0.900 0.001
30 min 60 min 0.700 0.036
60 min 60 min 0.700 0.036
15 min 15 min 0.857 0.007
Mean (0–60 min) 60 min 0.783 0.013
Discussion
Given that oxytocin levels have been demonstrated to correlate with some maternal physio-
logical and behavioral variables, including the level of maternal interaction and sensitivity to the
infant’s cues, this study explored whether the scores obtained on the MDORS correlated with
oxytocin and cortisol levels in dogs and their owners. In the present study, we demonstrated
that the scores of some items and subscales in the MDORS, describing the quality of the
relationship between dog owners and their dogs, correlated significantly with the owners’ as
well as their dogs’ oxytocin and cortisol levels.
The characteristics of the relationship between humans and dogs can be described by in-
ventories such as the MDORS. The items in this scale address both the positive and the neg-
ative aspects of the dog–owner relationship and they have been arranged into three subscales:
Dog–Owner Interaction, Perceived Emotional Closeness, and Perceived Costs (Dwyer, Bennett
and Coleman 2006). There are no normative values for the MDORS and so the results obtained
in the present study cannot be compared with those obtained in other studies.
In general, the owners participating in the present study described their relationship with
their dogs in very positive terms. In response to some of the items, almost all owners gave a
maximal score. For example, “How often do you hug your dog?” and “How often do you have
AZ VOL. 25(2).qxp:Layout 1 3/30/12 10:15 AM Page 224
your dog with you while relaxing, i.e., watching TV?” (mean of 4.9 out of 5 for both items),
supporting the premise that these owners had a close relationship with their dogs.
The correlation analysis showed that higher oxytocin levels in the owners were associated
with greater frequency in kissing their dogs and a perception that looking after their dog was
not difficult. It also showed that lower cortisol levels in the owners were associated with a per-
ception of being less bothered about the dog stopping them from doing things, a greater fre-
quency in bringing their dogs when visiting people, and a perception that the dog’s death
would be traumatic. Taken together, these results indicate that high levels of oxytocin and low
levels of cortisol in dog owners are related to owners having a perception of the relationship
with their dogs as pleasant and interactive and associated with few problems.
The scores obtained from the MDORS were also correlated with the dogs’ oxytocin and
cortisol levels. The correlation analysis showed that higher oxytocin levels in the dogs were
associated with greater frequency in being kissed by their owners and lower frequency in
getting food treats from their owners. In addition, the strength of the perceived bond corre-
lated with the dogs’ oxytocin levels. Higher oxytocin levels in the dogs were associated with
lower perceived cost by the owners and a more positive overall evaluation of the relationship
by the owners. These results indicate that high levels of oxytocin in the dogs are related to
increased interaction with the owner and with the owners seeing their dog as a positive and
pleasant companion.
The previous findings of positive correlations between maternal oxytocin levels and moth-
ers being more interactive with their children and also more sensitive to their children’s cues
(Feldman et al. 2007) give support to the idea that owners with high oxytocin levels may inter-
act more with their dogs. The positive relationships between the owners’ and the dogs’ oxy-
tocin levels indicate that there is a mutual relationship between dog owners and their dogs and
that this relationship influences their oxytocin levels, and perhaps also their cortisol levels. How-
ever, due to the correlational nature of this study, it cannot be concluded whether it is the high
oxytocin levels that generate the close and frequent interaction between owners and their dogs
or if it is the close and frequent interaction that generates the increased oxytocin levels.
While statistically significant positive relationships existed between the owner’s and the
dog’s oxytocin levels, no significant relationships were identified for cortisol. The reason why
no correlations were found for their cortisol levels is not known. However, cortisol levels are
easily affected by various kinds of stimuli, such as movement and activity, which might be the
case in this study.
Oxytocin is released not only in response to interactions between humans but also in re-
sponse to interactions between dogs and their owners (Odendaal and Meintjes 2003; Miller
et al. 2009; Handlin et al. 2011). Since cortisol levels are lowered by oxytocin, the correlations
between the MDORS scores and oxytocin and cortisol levels may both reflect the interaction
between dogs and their owners.
In the present study, we chose to study middle-aged (35–70 years) women and their
male Labrador Retriever, in order to keep variation due to gender, sex -steroid levels, and
breed to a minimum. Labradors are one of the most common companion dogs and are
considered friendly and easy to work with. In future studies, it would be interesting to study
other breeds, as well as to study both female and male owners, to see if the results differ.
Future studies should also include a larger number of participants compared with the pres-
ent study, in order to further evaluate the role of oxytocin and other hormones in the quality
of the human–dog relationship.
225 Anthrozoös
Handlin et al.
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If the MDORS continues to be used as a tool to evaluate the relationship between dog
owners and their companion dogs, it would be helpful to validate it across cultures and to
evaluate the effects of excluding single items.
In conclusion, the results from the present study suggest that owners’ perceptions of their
relationship with their dogs are related to the oxytocin, and to lesser extent cortisol, levels in
both owners and dogs. Whether the responses identified are innate or acquired over time
through the interaction with the dog cannot be determined by a correlational study and requires
further investigation.
Acknowledgements
We thank all the dogs and people who participated in the study and also Ulla Nilsson, Thomas
Gustavsson, and Sara Magnusson for assisting during the experiment.
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