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Abstract

The aim of this exploratory study was to determine heart rate and the levels of oxytocin, cortisol, and insulin in dogs and their owners in response to a short-term interaction. In addition, the dogs' behavior was studied. The owners' responses were compared with those obtained from a control group. Ten female volunteers and their own male Labrador dogs par-ticipated in an experiment during which the owner stroked, petted, and talked with her dog during the first 3 minutes. Blood samples were collected from both dog and owner before (0) and at 1, 3, 5, 15, 30, and 60 minutes after the start of the interaction. Blood samples were analyzed by EIA. Heart rate was monitored telemetrically. The data were analyzed using linear mixed models and paired t-tests. The dogs' oxytocin levels were significantly increased 3 minutes after the start of the interaction (p = 0.027). Cortisol levels were significantly increased after 15 and 30 minutes (p = 0.004 and p = 0.022, respectively), and heart rate was significantly decreased after 55 minutes (p = 0.008). The dogs displayed normal behaviors during the experiment. The owners' oxytocin levels peaked between 1 and 5 minutes after interaction (p = 0.026). No such effect was seen in the controls. Cortisol levels displayed a significant decrease at 15 or 30 minutes in both owners and controls, and insulin levels did so at 60 minutes (p = 0.030, p = 0.002 and p = 0.002,
Short-Term Interaction
between Dogs and Their
Owners: Effects on Oxytocin,
Cortisol, Insulin and Heart
Rate—An Exploratory Study
Linda Handlin*, Eva Hydbring-Sandberg,
Anne Nilsson, Mikael Ejdebäck*, Anna Jansson§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
§Department of Animal Nutrition and Management, Swedish Univer-
sity of Agricultural Sciences, Uppsala, Sweden
ABSTRACT The aim of this exploratory study was to determine heart rate
and the levels of oxytocin, cortisol, and insulin in dogs and their owners in
response to a short-term interaction. In addition, the dogs’ behavior was
studied. The owners’ responses were compared with those obtained from a
control group. Ten female volunteers and their own male Labrador dogs par-
ticipated in an experiment during which the owner stroked, petted, and talked
with her dog during the first 3 minutes. Blood samples were collected from
both dog and owner before (0) and at 1, 3, 5, 15, 30, and 60 minutes after the
start of the interaction. Blood samples were analyzed by EIA. Heart rate was
monitored telemetrically. The data were analyzed using linear mixed models
and paired t-tests. The dogs’ oxytocin levels were significantly increased 3
minutes after the start of the interaction (p= 0.027). Cortisol levels were
significantly increased after 15 and 30 minutes (p= 0.004 and p= 0.022,
respectively), and heart rate was significantly decreased after 55 minutes
(p= 0.008). The dogs displayed normal behaviors during the experiment. The
owners’ oxytocin levels peaked between 1 and 5 minutes after interaction
(p = 0.026). No such effect was seen in the controls. Cortisol levels displayed
a significant decrease at 15 or 30 minutes in both owners and controls, and
insulin levels did so at 60 minutes (p= 0.030, p= 0.002 and p= 0.002,
301 Anthrozoös DOI: 10.2752/175303711X13045914865385
ANTHROZOÖS VOLUME 24, ISSUE 3 REPRINTS AVAILABLE PHOTOCOPYING © ISAZ 2011
PP. 301–315 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
AZ VOL. 24 (3).qxp:Layout 1 6/29/11 3:35 PM Page 301
302 Anthrozoös
Short-Term Interaction between Dogs and Their Owners…
p< 0.0001, respectively). Heart rate decreased significantly in the owners at 55 and 60 minutes
(p= 0.0008) but not in the controls. In conclusion, short-term sensory interaction between dogs and
their owners influences hormonal levels and heart rate. However, further studies need to be
performed in order to better understand the effects of interaction between dogs and their owners.
Keywords: cortisol, heart rate, human–dog interaction, insulin, oxytocin
Human–animal interaction (HAI) has been shown to have positive effects on health
and well-being in humans. The acquisition of pets can result in a reduction in health
problems and an improvement in perceived health (Serpell 1991). Pet owners have
been shown to have lower levels of risk factors for cardiovascular disease, and after acute
myocardial infarction, dog owners are significantly less likely to die within 1 year, compared with
those who do not own dogs (Friedmann and Thomas 1995). Owning a pet is associated with
lower heart rate and blood pressure during basal and stressed conditions (Allen, Shykoff and
Izzo 2001; Allen, Blascovich and Mendes 2002). In addition, anxiety decreases in the presence
of a dog (Wilson 1991) and children having a dog present in their classroom display increased
social competence (Hergovich et al. 2002; Kotrschal and Ortbauer 2003).
The positive health consequences associated with HAI may be caused by oxytocin re-
lease induced by positive emotions such as affection and love (Uvnäs-Moberg 1997; 1998) and
by the physical interaction that takes place between the human and animal. The physical
interaction between humans and dogs involves various types of non-noxious sensory stimu-
lation such as touch, light pressure, warmth, and stroking as well as olfactory, auditory, and
visual cues.
Non-noxious sensory stimulation gives rise to physiological effects in anesthetized rats; for
example, decreased activity in the hypothalamic pituitary adrenal (HPA)-axis and in the sym-
patho-adrenal system, resulting in decreased cortisol and adrenalin levels and lowered blood
pressure. It further increases oxytocin levels and influences the levels of gastrointestinal hor-
mones, as a consequence of efferent vagal nerve activation (Kurosawa et al. 1982; Araki et al.
1984; Stock and Uvnäs-Moberg 1988; Uvnäs-Moberg et al. 1992; Kurosawa et al. 1995). In
unanesthetized rats, both physiological and behavioral effects are induced by non-noxious
sensory stimulation. Stroking of the abdomen (40 strokes/minute for 5 minutes) decreases
pulse rate and blood pressure for several hours (Lund et al. 1999), pain thresholds are in-
creased, and a sedative effect is induced. In addition, oxytocin is released (Agren et al. 1995;
Uvnäs-Moberg et al. 1996). Repeated exposure to stroking gives rise to long-lasting effects
such as an increased pain threshold, decreased blood pressure, and decreased levels of gas-
trointestinal hormones and energy expenditure, resulting in weight gain (Holst, Uvnäs-Moberg
and Petersson 2002; Lund et al. 2002; Holst et al. 2005). Newborn rats subjected to large
amounts of non-noxious sensory stimulation in the form of maternal sensory interaction dis-
play reduced fear, increased social interaction, and increased function of oxytocin receptors
in the amygdala as adults (Liu et al. 1997; Francis et al. 2002).
Similar effects, including decreased cortisol levels, can be observed in humans in response
to non-noxious sensory stimulation such as massage, skin-to-skin contact between mothers
and infants, and suckling in breastfeeding mothers (Uvnäs-Moberg et al. 1990; Nissen et al.
1996; Uvnäs-Moberg 1996; Uvnäs-Moberg and Eriksson 1996; Handlin et al. 2009). Taken to-
gether, these data show that non-noxious sensory stimulation has stress-reducing effects by
reducing the activity in the HPA-axis and by decreasing and increasing the activity in certain
aspects of the sympathetic and parasympathetic/vagal nervous systems, respectively.
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Oxytocin may mediate some of the effects mentioned above by actions in the brain, in
particular since some of the effects induced by non-noxious sensory stimulation are reversed
following the administration of oxytocin antagonists (Uvnäs-Moberg 1998; Uvnäs-Moberg and
Petersson in press). Oxytocin is produced in the supraoptic nucleus (SON) and paraventricu-
lar 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 is also released into important regulatory areas in the brain from nerves originating in
the PVN. Oxytocin stimulates social interactive behavior and promotes attachment between
individuals (Carter 1998). Oxytocin also induces, for example, anxiolytic-like effects and seda-
tive effects (Uvnäs-Moberg et al. 1994; Amico et al. 2004), decreases cortisol levels and blood
pressure, and influences the release of gastrointestinal hormones, for example, insulin (Pe-
tersson et al. 1996; Petersson, Hulting and Uvnäs-Moberg 1999; Petersson et al. 1999; Holst,
Uvnäs-Moberg and Petersson 2002).
Since non-noxious sensory stimulation gives rise to a multitude of effects that may in part
be mediated by oxytocin in both humans and animals, it is likely that oxytocin release and
oxytocin-mediated effects are induced during interaction between humans and dogs. Such ef-
fects might explain the health-promoting effects of HAI. This idea is supported by previous
studies which show that oxytocin is released in both dogs and humans when they interact
physically (Odendaal and Meintjes 2003; Miller et al. 2009).
The aim of this exploratory study was to test the hypothesis that oxytocin release and oxy-
tocin-mediated effects are induced in both dogs and their owners during a short period of in-
teraction characterized by caressing and stroking. To test the hypothesis, oxytocin levels were
measured in blood samples collected before, during, and after a short-term interaction be-
tween dogs and their owners. Since oxytocin influences the activity of the HPA axis and the
autonomic nervous system, cortisol levels were measured to reflect the activity in the HPA
axis, and insulin levels were measured to reflect vagal nerve tone. Heart rate was measured
to reflect both sympathetic and parasympathetic activity. The dogs’ behaviors were analyzed
to check that the dogs were well and were not stressed by the experiment.
Methods
Participants
Ten privately owned male Labrador dogs and their female owners were recruited through in-
formation provided at local workplaces and local veterinary clinics. The owners were informed
about the aim of the study and about the experimental setup. Women older than 30 years who
owned a male Labrador older than 1 year were included in the study. Owners and their dogs
who participated in the study did not have any illnesses. Ten female volunteers who did not
own a dog served as controls. The mean age of the owners and controls was 53 years
(SD = 10), and 42 years (SD = 8), respectively, and the mean age of the dogs was 4.7 years
(SD = 2.6). There was no significant difference in age between owners and controls. Due to
ethical and practical reasons, it was not possible to perform control experiments on the
privately owned dogs.
The study was conducted at the Swedish University of Agricultural Sciences in Skara,
Sweden. The experimental procedure for the humans was approved by the Local Ethics Com-
mittee in Uppsala, and the procedure for the dogs was approved by the Animal Ethics Com-
mittee in Uppsala. The use of privately owned dogs was approved by the National Board of
Agriculture. Before the experiment started, the owners were once more informed about the
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study, were given the opportunity to ask any questions regarding the experiment, and were
made aware that they could end their participation at any time. The owner then signed a written
consent form for participation in the study for both the dog and herself.
Experimental Setting
The owner and her dog arrived together at the testing facility, which consisted of a plain room
containing a desk, four chairs, a bookcase, and a water bowl for the dog. The owners sat in
a chair during the entire experiment. In addition, four other people were present in the room
during the experiment: an animal caretaker, a nurse, one person taking care of the blood
samples, and one person videotaping the experiment. None of these four persons were in
contact with the dog or the owner during the experiment except for the animal caretaker and
the nurse during the insertion of catheters and sampling of blood.
Preparations
An indwelling catheter was inserted into the cubital vein of the dog owners and the controls.
In order to facilitate the insertion of catheters and sampling of blood, the dogs were shaved
on the dorsal side of the distal part of a forelimb, where a local anesthetic plaster with prilo-
caine and lidocaine (EMLA®, AstraZeneca) was attached. The plaster was applied for 45 min-
utes and then an intravenous catheter was inserted into the cephalic vein. The catheter was
covered with Vetrap (CM), in order to prevent the dog from licking it.
The dogs were also shaved on a small area on the lateral side of the chest around which
a heart rate monitor (s610i TM, Polar precision performance, Polar Electro) was attached, with
the receiver placed a short distance away. The recording range was 30–240 beats/min and
the accuracy of the recordings was ± 1 beat/min. In order to maximize contact between the
heart rate monitor and the dogs’ skin, electrode gel (Blågel, Cefar) was used.
Heart rate monitors of the same type as for the dogs were attached around the chests of
the dog owners and the controls, with the receivers placed around their wrists. Heart rate was
monitored every 15th second in both dogs and humans. Due to technical problems, heart
rate was only measured in five controls.
The Interaction Experiment
Before the experiment started, the owner sat in a chair with her dog unrestrained, sitting or lying
beside her. The owner approached her dog at time point zero and started to pet and stroke
different parts of the dog’s body and talked to him for 3 minutes. The owner was then in-
structed to remain sitting in her chair and not to touch her dog for the rest of the experiment,
which lasted for a total of 60 minutes. If the dog attempted to interact with the owner during
the remaining time of the experiment, the owner was instructed to ignore this, with the result
that the dog stopped its attempts almost immediately. Verbal communication was allowed
during the whole experiment.
The conditions for the control group were the same as for the owners, with the exception
that there was no dog present: the participants went through the same preparations, sat in the
same chair in the same room with the same people present (except for the animal caretaker),
and blood samples were drawn in the same way at the same time points as for the owners.
The goal was to perform all experiments, for the owners and the controls, during the
evening, but due to the participants’ work schedules, some of the experiments were performed
during the morning (4 owners and 5 controls).
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Blood Sampling
The first blood samples were taken simultaneously from both the dog and the owner 30 min-
utes after insertion of the catheter and just before the owner started to interact with her dog
(basal = 0 min). Blood samples were then taken from both the dog and the owner at 1, 3, 5,
15, 30, and 60 minutes after the start of the interaction. Insertion of catheters and sampling
of blood in the dogs and humans were performed by the same experienced animal caretaker
and experienced nurse, respectively.
The blood samples were collected in 4 ml EDTA tubes containing 0.2 ml aprotinin
(Trasylol®, Bayer AB). The samples were immediately put on ice and then centrifuged at
1600 g for 20 minutes at +4ºC after which the plasma was collected and stored at
–20ºC, until analysis.
Hormone Analysis
Oxytocin levels were determined in humans and dogs using Correlate-EIATM Oxytocin En-
zyme Immunoassay Kit according to the manufacturer’s instructions (Assay Designs, Inc.
Ann Arbor, USA) (sensitivity 11.7 pg/ml, precision 9.1%). Cortisol levels were determined
using the DSL-10-2000 ACTIVE®Cortisol Enzyme Immunoassay Kit according to the man-
ufacturer’s instructions (Diagnostic Systems Laboratories, Inc. Texas, USA) (sensitivity 2.76
nmol/l, precision 10.3%). The dogs’ insulin levels were determined using the Mercodia Ca-
nine Insulin ELISA 10-1203-1 according to the manufacturer’s instructions (Mercodia AB,
Uppsala, Sweden) (sensitivity 0.01g/l, precision 4.6%), and the humans’ insulin levels
were determined using the Mercodia Insulin ELISA 10-1113-10 according to the manu-
facturer’s instructions (Mercodia AB, Uppsala, Sweden) (sensitivity 1 mU/l, precision 5%).
Standards and controls were always included, as recommended by the manufacturers.
Before the oxytocin analysis, the samples from the humans were diluted five times in the
assay buffer. Before the cortisol analysis, the samples from the dogs were diluted two times
in zero standard buffer.
All washing procedures were performed using an Anthos Fluido microplate washer (Anthos
Labtec Instruments GmbH), and the absorbance was read using a Multiskan Ex microplate
photometer (Thermo Electron Corporation). The color development of the samples was read
at 405 nm for oxytocin and at 450 nm for cortisol and insulin, with background correction at
580 nm for oxytocin and 620 nm for cortisol. Ascent software was used for creation of
standard curves, curve fitting, and calculation of concentrations (Ascent software ver 2.6 for
iEMS Reader MF and multiscan).
One dog was excluded from the oxytocin analysis because his hormone levels were out-
side the range of detection.
Observations of the Dogs’ Behaviors
The entire interaction experiment (60 min) was videotaped, in order to control for how the dogs
behaved and experienced the situation. The total time the dog spent sitting, standing, lying
down (i.e., both on the chest and on the side), or walking around was recorded. The total time
the dog was resting (i.e., put his head on the floor) while lying down, the number of times the
dog changed the position of his head while lying down (i.e., when the dog moved his head from
left to right or from right to left), and the number of times the dog changed body positions
while lying down (i.e., how many times the dog moved his whole body from one side to the
other) were recorded. The number of times the dog licked himself around the mouth was also
recorded, since this may be an indicator of stress in dogs.
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Statistical Analysis
The data were analyzed using SAS version 9.1 for Windows (Cary, NC, USA; 2002) and Sta-
tistical Package for the Social Sciences (SPSS/PASW) version 17.0 (Chicago, IL, USA; 2009).
Mean values with corresponding standard errors (SE) were used to describe the hormone lev-
els and the heart rate of the dogs, owners, and controls, as well as to describe the different
behaviors studied in the dogs.
The distributions of hormone levels for dogs and humans were positively skewed and
therefore normalized by logarithmic transformation (log10) before statistical analysis was per-
formed. The heart rate monitors registered the heart rate every 15th second, but only the
recordings obtained at each 5th min were used in the statistical analysis.
Sampling time was considered as a categorical predictor and the change in heart rate and hor-
mone levels at specific time points compared with the start of the dog–owner interaction (0 min)
was analyzed using linear mixed models in the MIXED procedure of SAS, one model for each trait.
For dogs, the models contained sampling time, and the model of cortisol also contained a pre-
dictor representing time of day for blood sampling (morning or evening); timing had no significant
effect on the other traits and was not included in these models. For humans, the models contained
sampling time, a variable representing group (owner or control), and the interaction between time
and group; again, the cortisol model contained a predictor for time of day. Correlation between
samples within participants was accounted for by a REPEATED statement and, due to the rela-
tively large number of unequally distributed time points for hormones, a compound symmetry
correlation structure was applied. Satterthwaite denominator degrees of freedom were specified.
The oxytocin level at 3 min was thus compared with the 0 min level. In contrast, the corti-
sol levels at 15 and 30 min were compared with 0 min. Likewise, the insulin level at 60 min and
heart rate at 55 and 60 min were tested. Time points for comparisons were selected based
on previous research and experience, and predicted values (least-squares means) were
compared using t-tests. P values < 0.05 were considered statistically significant. In dogs, a total
of 63, 70, 70, and 129 observations were used in the models of oxytocin, cortisol, insulin, and
heart rate, respectively; in humans, 139, 139, 137, and 195 observations were used,
respectively. The models were validated by examining the normality of raw residuals.
In a complementary analysis, extreme values of oxytocin and cortisol were considered.
The maximum oxytocin level obtained at 1, 3, or 5 min was recorded for each participant. In
the same way, the maximum (in dogs) and minimum (in humans) cortisol levels obtained at 15
or 30 minutes were recorded. Again, these time points were chosen based on earlier scientific
evidence. Paired t-tests were calculated to test for differences between the extreme values and
the basal values.
Results
Hormone levels and heart rate for all participants are presented in Tables 1 and 2. For
information about differences between least-squares means at selected time points, standard
errors, and p values generated in the linear mixed models, see Table 3.
Dogs
Hormone Levels: The dogs’ oxytocin levels were significantly increased 3 min after the start of
the dog–owner interaction (p= 0.027) (Table 3). In addition, the dogs’ peak oxytocin levels
recorded at 1, 3, or 5 min were significantly higher compared with the levels collected at time
point 0 min (t= 2.99; df = 8; p= 0.017) (Figure 1; Table 1).
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The dogs’ mean cortisol levels exhibited a delayed and protracted rise, and cortisol levels
were significantly increased after 15 and 30 min after the start of the dog–owner interaction,
when compared with levels obtained before the interaction started (p= 0.004 and p= 0.022,
respectively) (Table 3). A significant peak in the dogs’ cortisol levels during the same time period
could not be demonstrated with the paired t-test (p= 0.146) (Figure 2; Table 1). The levels of
cortisol were 41% higher in the morning than in the evening (p= 0.048).
Insulin levels did not change significantly during the experiment (Figure 3; Tables 1 and 3).
Heart Rate: There was a significant decrease in the dogs’ heart rate at 55 min compared with
at the start of the interaction (p= 0.008). In contrast, there was no significant change at 60 min
(Figure 4; Tables 2 and 3).
Behavioral Observations: These were made from the videotapes and the results are summa-
rized in Table 4. The dogs displayed normal behaviors during the experiment. They walked
around for a short while but were mostly resting.
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Handlin et al.
Table 1. Hormone concentrations during the interaction experiment, and maximum levels of
oxytocin and maximum levels (in case for the dogs) and minimum levels (in case of the
humans) of cortisol for the participants (10 male Labrador dogs, 10 female owners, and 10
control persons). Means (SE) are shown and are based on non-transformed data.
0 min 1 min 3 min 5 min 15 min 30 min 60 min Min/Max
Values
Oxytocin Levels (pmol/l)
Dogs 155.8 211.2 236.9 178.6 163.5 157.5 157.5 251.8
(26.9) (30.7) (38.7) (29.6) (34.5) (36.0) (41.1) (34.5) (max)
Owners 168.5 169.8 180.6 170.2 146.4 171.3 165.1 187.0
(34.6) (34.1) (34.4) (27.8) (34.7) (34.2) (26.3) (33.6) (max)
Controls 208.6 208.2 212.1 212.5 215.6 198.0 212.4 166.1
(62.0) (64.3) (68.2) (70.0) (68.0) (62.9) (67.4) (43.7) (max)
Cortisol Levels (nmol/l)
Dogs 168.4 169.4 168.1 180.1 224.1 202.8 190.2 237.3
(14.8) (16.1) (15.3) (17.8) (32.5) (18.3) (18.8) (30.3) (max)
Owners 389.8 382.7 382.7 387.6 362.1 331.6 305.2 316.9
(119.7) (107.4) (109.9) (119.6) (107.9) (80.1) (62.6) (80.5) (min)
Controls 381.5 379.4 375.5 371.9 352.7 332.6 345.5 319.9
(30.9) (25.9) (27.8) (28.9) (24.2) (33.5) (37.2) (26.5) (min)
Insulin Levels (pmol/l)
Dogs 37.5 32.6 28.5 30.8 34.6 32.4 42.9
(7.8) (5.4) (3.4) (3.8) (8.9) (6.7) (8.6)
Owners 159.6 149.0 142.5 151.8 142.2 126.8 101.4
(42.5) (36.8) (31.7) (38.8) (53.9) (44.4) (35.2)
Controls 155.2 159.4 154.7 148.1 159.0 114.1 51.4
(67.6) (68.4) (58.4) (48.7) (44.9) (42.3) (32.7)
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Dog Owners and Controls
Hormone Levels: Neither owners nor controls showed a significant change in oxytocin levels
after 3 min of dog–owner interaction (Table 3). However, the owners’ peak oxytocin levels
recorded at 1, 3, or 5 min were significantly higher compared with the levels collected at time
point 0 min (t= 2.66; df = 9; p= 0.026). Such an effect was not seen in the controls (p=
0.417) (Figure1; Tables 1 and 3).
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Short-Term Interaction between Dogs and Their Owners…
Table 2. Heart rate (beats/min) during the interaction experiment for the participants (10 male
Labrador dogs, 10 female owners, and 10 control persons). Mean (SE) values are shown and
are based on non-transformed data.
0 51015202530354045505560
min min min min min min min min min min min min min
Dogs 94 94 83 88 84 67 75 88 87 82 80 67 76
(11) (8) (9) (9) (9) (7) (3) (10) (14) (15) (15) (8) (4, 2)
Owners 78 78 78 76 74 74 74 71 72 71 72 71 71
(5) (5) (4) (4) (4) (4) (4) (4) (3) (3) (4) (4) (4)
Controls 74 68 70 70 72 68 70 72 73 70 73 71 71
(6) (5) (5) (5) (6) (6) (5) (6) (6) (5) (3) (6) (4)
Table 3. Back-transformed least-squares means (LSM) at start of dog–owner interaction
(0 min) and at selected time points, standard errors (SE), and pvalues generated from the
linear mixed models of hormone levels and heart rate.
Trait and Time Point LSM SE p
Dogs
Oxytocin at 0 and 3 min (pmol/l) 139.5; 210.1 1.20 0.027
Cortisol at 0 and 15 min (nmol/l) 162.2; 205.1 1.08 0.004
Cortisol at 0 and 30 min (nmol/l) 162.2; 195.0 1.08 0.022
Insulin at 0 and 60 min (pmol/l) 32.4; 31.4 1.22 0.882
Heart rate at 0 and 55 min (beats/min) 94.2; 66.9 10.02 0.008
Heart rate at 0 and 60 min (beats/min) 94.2; 83.1 10.32 0.283
Owners
Oxytocin at 0 and 3 min (pmol/l) 147.2; 160.3 1.07 0.191
Cortisol at 0 and 15 min (nmol/l) 297; 263.5 1.06 0.055
Cortisol at 0 and 30 min (nmol/l) 297; 271.6 1.06 0.136
Insulin at 0 and 60 min (pmol/l) 129.5; 69.8 1.21 0.002
Heart rate at 0 and 55 min (beats/min) 78.1; 71.4 1.96 0.0008
Heart rate at 0 and 60 min (beats/min) 78.1; 71.4 1.96 0.0008
Controls
Oxytocin at 0 and 3 min (pmol/l) 159.2; 155.2 1.07 0.697
Cortisol at 0 and 15 min (nmol/l) 369.0; 345.1 1.06 0.266
Cortisol at 0 and 30 min (nmol/l) 369.0; 318.4 1.06 0.015
Insulin at 0 and 60 min (pmol/l) 84.4; 28.4 1.23 < 0.0001
Heart rate at 0 and 55 min (beats/min) 73.8; 71.2 2.77 0.350
Heart rate at 0 and 60 min (beats/min) 73.8; 71.0 2.77 0.314
AZ VOL. 24 (3).qxp:Layout 1 6/29/11 3:35 PM Page 308
The owners’ cortisol levels tended to be decreased at 15 min after the start of the inter-
action with the dog (p= 0.055) but not at 30 min (p= 0.14) (Table 3). Their minimum cortisol
309 Anthrozoös
Handlin et al.
220
195
170
145
120
0
Oxytocin (pmol/l)
Dogs
10 20 30 40 50 60
Time (min)
Owners
Controls
Figure 1. Predicted levels of oxytocin (pmol/l) in 10 male Labrador dogs,
10 female owners, and 10 female control persons; back-transformed
least-squares means from a linear mixed model. The first blood sample
was taken immediately before the owner started to interact with her dog
(0 min) and other samples were taken 1, 3, 5, 15, 30, and 60 min later.
Standard errors for oxytocin levels at 0 and 3 minutes in dogs = 1.2, in
owners = 1.22, and in controls = 1.22.
400
350
300
250
200
150
100
0
Cortisol (nmol/l)
Dogs
10 20 30 40 50 60
Time (min)
Owners
Controls
Figure 2. Predicted levels of cortisol (nmol/l) in 10 male Labrador dogs,
10 female owners, and 10 female control persons; back-transformed
least-squares means from a linear mixed model. The first blood sample
was taken immediately before the owner started to interact with her dog
(0 min) and other samples were taken 1, 3, 5, 15, 30, and 60 min later.
Standard errors for cortisol levels at 0, 15 and 30 minutes in dogs = 1.1,
in owners = 1.18, and in controls = 1.18.
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310 Anthrozoös
Short-Term Interaction between Dogs and Their Owners…
140
120
100
80
60
40
20
0
Insulin (pmol/l)
Dogs
10 20 30 40 50 60
Time (min)
Owners
Controls
Figure 3. Predicted levels of insulin (pmol/l) in 10 male Labrador dogs,
10 female owners, and 10 female control persons; back-transformed
least-squares means from a linear mixed model. The first blood sample
was taken immediately before the owner started to interact with her dog
(0 min) and other samples were taken 1, 3, 5, 15, 30, and 60 min later.
Standard errors for insulin levels at 0 and 60 minutes in dogs = 1.22, in
owners = 1.03, and in controls = 1.03.
100
95
90
85
80
75
70
65
60
0
Heart Rate (beats/min)
Dogs
10 20 30 40 50 60
Time (min)
Owners
Controls
Figure 4. Predicted levels of heart rate (beats/min) in 10 male Labrador
dogs, 10 female owners, and 10 female control persons; least-squares
means from a linear mixed model. Standard errors at 0, 55, and 60
minutes in dogs = 10.08, in owners = 4.00, and in controls = 5.66.
levels reached at 15 or 30 min were significantly decreased compared with the levels collected
at time point 0 min (t= –2.573; df = 9; p= 0.030) (Figure 2; Table 1).
The controls did not display a significant decrease in cortisol levels at 15 min (p= 0.266),
but did so at 30 min (p= 0.015) (Table 1). In addition, their minimum cortisol levels recorded
at 15 or 30 min were significantly decreased compared with the levels collected at time point
AZ VOL. 24 (3).qxp:Layout 1 6/29/11 3:35 PM Page 310
0 min (t= –4.275; df = 9; p= 0.002) (Figure 2; Table 1). The levels of cortisol for both owners
and controls were 80% higher in the morning than in the evening (p= 0.010).
In both owners and controls, there was a significant decrease in insulin levels at 60 min
(p= 0.0018 and p< 0.001, respectively) (Figure 3; Table 3).
Heart Rate: Heart rate was significantly decreased at 55 and 60 min in the owners (p= 0.0008
and p= 0.0008, respectively). In contrast, no change in heart rate was seen in the controls
(Figure 4; Table 3).
Differences between Owners and Controls Over Time
There was a significant statistical interaction between time and group for insulin and heart
rate (p= 0.045 and p= 0.011, respectively) but not for oxytocin and cortisol (p= 0.650 and
p= 0.906, respectively).
Discussion
The aim of this exploratory study was to test the hypothesis that oxytocin release and oxytocin-
mediated effects are induced in both dogs and their owners in response to physical interac-
tion. The results show that short-term interaction between a dog and its owner is associated
with a significant increase in oxytocin and cortisol levels in the dog. In addition, oxytocin in-
creased significantly in the owners but not in the controls, cortisol and insulin levels decreased
in both the owners and the controls, while heart rate decreased significantly only in the own-
ers. To our knowledge, the present study is unique since it was performed under standard-
ized conditions with an equal focus on the humans and dogs, and repeated observations
were made before, during, and after interaction between the dog and its owner.
We chose to study male Labrador dogs and their female owners in order to keep variation
due to breed and sex steroid levels to a minimum. In addition, Labradors are one of the most
common companion dogs and are friendly and prone to interaction with humans, which is ad-
vantageous when studying human–animal interaction
In a previous study performed by Odendaal and Meintjes in 2003, some effects were noted
in response to interaction between dogs and humans. The levels of -endorphin, oxytocin,
prolactin, phenyl acetic acid, and dopamine all increased in the dogs and humans after inter-
action, whereas cortisol increased in the dogs and decreased in the humans (Odendaal and
Meintjes 2003). Although the results from that study display effects of interaction, the differ-
ences between it and our study regarding participants, experimental layout (only two blood
311 Anthrozoös
Handlin et al.
Table 4. Behavior of 10 male Labrador dogs during 60 min of human
interaction; means and their standard errors (SE).
Behavior Mean (SE)
Total time sitting (min:sec) 4:30 (1:24)
Total time standing (min:sec) 2:00 (0:42)
Total time lying down (min:sec) 52:00 (2:00)
Total time walking around (min:sec) 2:00 (0:36)
Total time resting while lying down (min:sec) 30:00 (4:14)
Licking around mouth (number of times) 44 (13)
Position changes of the head while lying down (number of times) 27 (4)
Position changes total (number of times) 17 (4)
AZ VOL. 24 (3).qxp:Layout 1 6/29/11 3:35 PM Page 311
samples collected before interaction and one collected between 4 and 24 minutes versus
repeated blood samples collected at different time points during the experiment), and differ-
ent methods for analyzing hormone levels (yielding extremely different hormone levels) makes
further comparisons difficult.
Recently, Miller et al. (2009) showed that women increase their oxytocin levels significantly
after interaction with their own dog. However, the same response was not observed in men.
That study focused only on humans, and only pre- and post observations were made (Miller
et al. 2009).
Nagasawa et al. (2009) reported increased oxytocin levels in the urine of humans in re-
sponse to gaze and touch (Nagasawa et al 2009). However, the relationship between oxytocin
levels in plasma, which mainly reflect oxytocin release from the pituitary, and oxytocin detected
in urine is at present unclear (Uvnäs-Moberg, Handlin and Petersson 2011).
Touch and massage-like stroking of rats and close physical contact in humans increases
oxytocin levels (Stock and Uvnäs-Moberg 1988; Nissen et al. 1995; Lund et al. 2002). Against
this background, it is likely that the distinct and short-lasting rise of oxytocin levels in the dogs
and the increased peak levels in the owners during our experiment were caused by the stroking
and petting performed by the owner.
In addition, non-noxious sensory stimulation induces stress-reducing effects in many dif-
ferent species. Rats being stroked on the abdomen show decreased blood pressure (Lund et
al. 1999). Cows being brushed on the abdomen show decreased heart rate and cortisol lev-
els (E. Wredle, personal communication). Skin-to-skin contact between mother and infant in-
duces lowering of blood pressure and cortisol levels in mothers and decreases cortisol levels
and increases cutaneous circulation in the infants (Nissen et al 1996; Uvnäs-Moberg 1996;
Uvnäs-Moberg and Eriksson 1996; Morelius, Theodorsson and Nelson 2005; Jonas et al.
2008; Handlin et al. 2009). Further, the levels of gastrointestinal hormones, including insulin,
are also influenced by stroking (Uvnäs-Moberg et al. 1992; Holst et al. 2005).
Since oxytocin is released by sensory stimulation, the interaction between the dogs and
owners may have decreased cortisol levels and heart rate via oxytocin released into the brain.
During the interaction experiment, though, the dogs displayed an increase in cortisol levels. A
rise in cortisol levels is often connected with high stress levels. It may, however, also reflect ini-
tiation of physical activity. In the present experiment, the dogs were behaviorally activated in
response to the interaction. Since cortisol levels in the circulation rise with a 15 to 20 min delay,
we suggest that the increase in the dogs’ cortisol levels reflect an increase in the locomotor
activity induced by the interaction with the owner. The increase was not confirmed by the com-
plementary paired t-test of maximum values at 15 or 30 min, which is probably explained by
the small number of participants.
The expected fall in insulin levels normally induced by sensory stimulation was not ob-
served in the present study. The owners were instructed not to feed their dogs just before ar-
riving at the testing facility. However, it turned out that some dogs had received food just before
arriving. A different pattern of insulin levels might have been obtained if all dogs had either
been fasted or fed before the start of the experiment, since feeding influences insulin levels.
The dogs’ heart rate was significantly decreased after 55 but not after 60 minutes. Oxytocin
induces, via effects in the brain, a decrease in sympathetic and an increase in parasympathetic
nervous tone. These changes influence cardiovascular function and hence oxytocin released
in the brain may have contributed to the temporary decrease in heart rate observed. The rea-
son for not seeing a significant decrease also after 60 minutes is probably due to the fact that
312 Anthrozoös
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a blood sample was collected at this time point, which may have resulted in a slight activation
of the sympathetic nervous system.
It is clear that the response in dogs to dog–owner interaction is complex and involves en-
docrine and physiological reactions reflecting both activation and relaxation. In the present study,
the interaction experiment was performed in an unfamiliar room. However, the time that had
elapsed from entering the room until the start of the experiment gave the dogs time to adjust to
the unfamiliar surroundings. The results from the behavior analysis indicated that the dogs dis-
played normal behavior and therefore they seemed to tolerate the experimental situation well.
The owners’ oxytocin levels peaked between 1 and 5 min after interaction. This was not
seen in the controls. These data confirm the results of Miller et al. (2009) and Odendaal and
Meintjes (2003). The design of the present experiment, allowing the owner to be in the same
room as the dog as well as being aware of the interaction before it started, might explain why
the rise in circulating oxytocin levels occurred at different time points.
Both owners and controls displayed decreased cortisol levels over time. Perhaps the ex-
perimental situation, involving blood sampling, was perceived as stressful, which might have
caused a rise in cortisol levels in both groups, and then a decrease over time in both.
In addition, insulin levels fell over time in both owners and controls. Since feeding was not
controlled for, any effects caused by the sensory interaction in the owners might have been
concealed by parallel feeding-related changes in glucose and insulin levels.
The observation that the owners’ heart rate decreased significantly suggests that interaction
with the dog might have induced a slight anti-stress effect in the owners. This effect may be a
consequence of the oxytocin released in the brain caused by the sensory interaction. This find-
ing may be of great importance, since it may be easier to demonstrate a decreased activity in
the sympathetic nervous system than in the HPA-axis as a consequence of (sensory) interaction.
The ambition was to perform all experiments, for the owners and the controls, during the
evening, but due to the participants’ work schedules’ some of the experiments were per-
formed during the morning (4 owners and 5 controls). Oxytocin and insulin are not known to
have circadian rhythms, and hence the results for these hormones are not likely to have been
affected by the experiment being conducted at different times of day. In contrast, cortisol has
a circadian rhythm, with levels being highest in the morning and decreasing throughout the day
(Arlt and Stewart 2005). In line with this, cortisol levels were significantly higher in the morning
than in the afternoon in both humans and dogs.
Our results show that there is a release of oxytocin and that some oxytocin-mediated ef-
fects can be observed in dogs and their owners when they interact with each other. Since this
is an exploratory study with only 10 dog–owner pairs participating, the results need to be
interpreted with caution and further studies need to be performed with a larger number of par-
ticipants and under even more standardized conditions. This will facilitate better recording and
understanding of the physiological and behavioral responses in dogs and their owners as a
consequence of interaction. In addition, it would be interesting to study the consequences of
interaction between both female and male dogs and female and male owners, as well as
interaction with dogs and an unfamiliar person.
Acknowledgements
We thank all the dogs and humans who participated in the study and also Ulla Nilsson, Thomas
Gustavsson, and Sara Magnusson for assisting during the experiment. A special thank you to
Jan Hultgren for the statistical analysis.
313 Anthrozoös
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... Within the broader human-dog interaction literature, a larger number of studies have examined peripheral oxytocin's relationship with human-dog interaction, particularly within an affiliative context. In this literature, there is substantial heterogeneity in sample collection methods to ascertain peripheral oxytocin concentration within dogs (37), with blood sampling previously appearing to be the most frequently used [e.g., (83)(84)(85)(86)(87)] followed by urine sampling [e.g., (88)(89)(90)(91)]. Recently, saliva sampling has emerged as a leading method [e.g., (36)(37)(38)]. ...
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... To shed light on the mechanisms of canine social susceptibility, the same experimental paradigm was used to test the effect of intranasal oxytocin treatment. It has been suggested that positive social interactions with the owner increase endogenous oxytocin levels of both the dogs and their owners [21][22][23], although recent research suggest that such effects are conditional on the life experiences of the individuals [24]. At the same time, intranasal oxytocin administration has been shown to influence many aspects of dogs' social behaviour (e.g., affiliative behaviour [25], positive expectation bias [26], use of human pointing [27], processing of emotional faces [28], gazing and social proximity [24]). ...
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Recent evidence suggests a human-like susceptibility to social influence in dogs. For example, dogs tend to ignore their ‘natural’ preference for the larger amount of food after having seen a human’s explicit preference for a smaller quantity. However, it is still unclear whether this tendency to conform to the partner’s behaviour can be influenced by social stimuli and/or the neurohormone oxytocin as primers to prosocial predispositions. In Experiment I, eighty two dogs were tested using Prato-Previde et al.’s food quantity preference task. In Experiment I, we investigated in a 2 × 2 design how (i) a 10-minute-long social stimulation by the owner versus a socially ignoring pre-treatment as well as (ii) on-line ostensive communications versus no communication during task demonstration affect dogs’ (N = 82) choices in the abovementioned food choice task. Results indicate that the owners’ pre-treatment with social stimuli (eye contact, petting) increased dogs’ susceptibility to the experimenter’s food preference, but the salient ostensive addressing signals accompanying human demonstration masked this social priming effect. In Experiment II, N = 32 dogs from the subjects of Experiment I were retested after oxytocin (OT) or placebo (PL) pre-treatments. This experiment aimed to study whether intranasal administration of oxytocin as compared to placebo treatment would similarly increase dogs’ tendency to re-enact the human demonstrator’s counterproductive choice in the same task. Results showed an increased susceptibility to the human preference in the OT group, suggesting that both socially stimulating pre-treatment and the intranasal administration of oxytocin have similar priming effects on dogs’ social susceptibility.
... Marcus and colleagues [56] propose a more direct relationship, suggesting that this occurs by the interaction exerting an effect on certain biological markers that correspond to pain, such as cortisol, as well as the cardiac indicators of stress, such as blood pressure and heart rate. It has also been suggested that pain reduction may be influenced by the release of beneficial hormones and neurochemicals (e.g., oxytocin), as well as decreased levels of stress hormones (i.e., cortisol) when petting an animal [57][58][59][60]. Central nervous system mechanisms may be involved through activation of endogenous pain inhibitory processes, and release of pain relieving neurochemicals such as endogenous opioids and oxytocin [59,61,62]. ...
... It has also been suggested that pain reduction may be influenced by the release of beneficial hormones and neurochemicals (e.g., oxytocin), as well as decreased levels of stress hormones (i.e., cortisol) when petting an animal [57][58][59][60]. Central nervous system mechanisms may be involved through activation of endogenous pain inhibitory processes, and release of pain relieving neurochemicals such as endogenous opioids and oxytocin [59,61,62]. ...
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Context Pain is a primary reason individuals attend an Emergency Department (ED), and its management is a concern. Objectives Change in symptoms and physiologic variables at 3 time points pre-post a ten-minute St. John Ambulance therapy dog team visit compared to no visit in ED patients who experienced pain. Design, setting and participants Using a controlled clinical trial design, pain, anxiety, depression and well-being were measured with the Edmonton Symptom Assessment System (revised version) (ESAS-r) 11-point rating scales before, immediately after, and 20 minutes post- therapy dog team visit with Royal University Hospital ED patients participating in the study (n = 97). Blood pressure and heart rate were recorded at the time points. Control data was gathered twice (30 minutes apart) for comparison (n = 101). There were no group differences in age, gender or ethnicity among the control and intervention groups (respectively mean age 59.5/57.2, ethnicity 77.2% Caucasian/87.6%, female 43.6% /39.2%, male 56.4%/60.8%,). Intervention 10 minute therapy dog team visit in addition to usual care. Main outcome measures Change in reported pain from pre and post therapy dog team visit and comparison with a control group. Results A two-way ANOVA was conducted to compare group effects. Significant pre- post-intervention differences were noted in pain for the intervention (mean change int. = -0.9, SD = 2.05, p = .004, 95% confidence interval [CI] = [0.42, 1.32], η p ² = 04) but not the control group. Anxiety (mean change int. = -1.13, SD = 2.80, p = .005, 95% CI = [0.56, 1.64], η p ² = .04), depression (mean change int. = -0.72, SD = 1.71, p = .002, 95% CI = [0.39, 1.11], ηp ² = .047), and well-being ratings (mean change int. = -0.87, SD = 1.84, p < .001, 95% CI = [0.49, 1.25], ηp ² = .07) similarly improved for the intervention group only. There were no pre-post intervention differences in blood pressure or heart rate for either group. Strong responders to the intervention (i.e. >50% reduction) were observed for pain (43%), anxiety (48%), depression (46%), and well-being (41%). Conclusions Clinically significant changes in pain as well as significant changes in anxiety, depression and well-being were observed in the therapy dog intervention compared to control. The findings of this novel study contribute important knowledge towards the potential value of ED therapy dogs to affect patients’ experience of pain, and related measures of anxiety, depression and well-being. Trial registration This controlled clinical trial is registered with ClinicalTrials.gov, registration number NCT04727749 .
... Participants experienced three minutes of either the HAI or control condition. We based this timing on changes observed in cortisol, oxytocin, and heart rate after a three-minute dog interaction in Handlin et al. (2011). Participants were not informed which of the three-minute conditions they were assigned to experience until the pre-condition phase was completed. ...
... Perhaps exposure to nature can reach the threshold for triggering these effects easily, but the threshold is higher or harder to reach for animal interactions. Or the time lag for these effects may be delayed (e.g., Handlin et al., 2011). Thus, experimental design could be critical for studying HAI effects on cognition. ...
Article
Human-animal interaction has clear positive effects on people’s affect and stress. But less is known about how animal interactions influence cognition. We draw parallels between animal interactions and exposure to natural environments, a research area that shows clear improvements in cognitive performance. The aim of this study is to investigate whether interacting with animals similarly enhances cognitive performance, specifically executive functioning. To test this, we conducted two experiments in which we had participants self-report their affect and complete a series of cognitive tasks (long-term memory, attentional control, and working memory) before and after either a brief interaction with a dog or a control activity. We found that interacting with a dog improved positive affect and decreased negative affect (in one of the two experiments), stress, and anxiety compared to the control condition. However, we did not find effects of animal interaction on long-term memory, attentional control, or working memory. Thus, we replicated existing findings providing evidence that interacting with animals can improve affect, but we did not find similar improvements in cognitive performance. These results suggest that either our interaction was not of sufficient dose or timed appropriately to elicit effects on cognition or the mechanisms underlying effects of human-animal interaction on cognition differ from effects generated by other cognition-enhancing interventions such as exposure to nature. Future research should continue to increase knowledge of the connection between nature exposure and human-animal interaction studies to build our understanding of cognition in response to animal interactions.
... An increasing number of papers suggest that canine-assisted interventions (CAI) may have physical and psychological benefits for numerous target groups of varying ages and diagnoses (1)(2)(3)(4)(5). Neutral or positive impacts of CAI sessions on dog welfare are documented, based on physiological parameters (e.g., oxytocin levels, a negative feedback regulator that culminates with a decrease in cortisol, heart rate or blood pressure (6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17) and behaviors such as playing, leaning toward, nudging, sniffing or licking the client (18)(19)(20)(21)(22). The dog's temperament and individuality is seldom investigated, although it is likely that this influences physiological and behavioral outcomes (23). ...
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CAIs (canine-assisted interventions) include “canine-assisted therapy” in which a therapist sets client-oriented goals, ’canine-assisted activities’ with recreational goals for clients, and ’canine-assisted education/learning’ in which teachers or coaches create learning goals for students or clients. CAIs vary in nearly every way; their only common trait is the involvement of dogs to respond to human need. However, the benefits of involving dogs are highly dependent on the animal’s health and behavior. A dog exhibiting negative behavior or an unwell dog might pose a risk, especially for CAI target groups, specifically individuals with immunosuppression, chronic illness, children, elderly, etc. Therefore, positive animal welfare as preventative medicine to avoid incidents or transmission of zoonosis is an attractive hypothesis, with implications for human and animal, health and well-being. This review aims to summarize the current published knowledge regarding different aspects of welfare in CAIs and to discuss their relevance in the light of health and safety in CAI participants. As method for this study, a literature search was conducted (2001–2022) using the Prisma method, describing issues of dog welfare as defined in the Welfare Quality® approach. This welfare assessment tool includes 4 categories related to behavior, health, management, and environment; it was, therefore, applicable to CAIs. Results indicate that dogs working in CAIs are required to cope with diverse variables that can jeopardize their welfare. In conclusion, we propose regular welfare assessments for dogs in CAIs, which would also protect the quality of the CAI sessions and the clients’ safety and well-being.
... Friendly interaction between humans and animals is linked to oxytocin release and oxytocin associated effects (Handlin et al., 2011;Beetz et al., 2012). In this issue interaction between elderly humans and dogs was demonstrated to be linked to increased finger temperature (Nilsson et al.). ...
... A paucity of research has highlighted the psychosocial and psychophysiological effects of HAIs [35,36] and has pointed to the positive impacts of childhood pets for socioemotional and behavioural development [10,37]. For example, it has been suggested that engagement with animals can help children to self-regulate, including fostering the social regulation of emotion and enhancing cognitive control through the animals' ability to respond to the child's attachment-related behaviour [23,38,39]. ...
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Emerging evidence suggests that pet dogs can offer features of a secure attachment which has been associated with healthy psychological development across the lifespan. Limited research has investigated the underpinning mechanisms that may contribute to the benefits and risks of child–dog attachment during childhood. This study aimed to test the potential mediating role of caregiver-observed positive and negative child–dog behaviours, on the relationship between child-reported child–dog attachment, and caregiver-reported child psychopathology and emotion regulation. Data from 117 caregiver reports and 77 child self-reports were collected through an online survey in the context of the COVID-19 pandemic. Parallel mediation analyses indicated that child–dog attachment had a significant indirect effect on conduct problems through negative child–dog behaviours only. Child–dog attachment had a significant indirect effect on emotional symptoms, peer problems, prosocial behaviour, emotion regulation, and emotional lability/negativity through both positive and negative child–dog behaviours. Although this study found modest effect sizes, the findings suggest that the types of interactions that children engage in with their pet dogs may be important mechanisms through which pet attachment contributes to psychological development throughout childhood, and therefore further attention is warranted. Positive and safe child–dog interactions can be facilitated through education and intervention, which may have implications for promoting positive developmental outcomes.
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Lay abstract: Children with autism typically experience difficulties interacting socially with others when compared to their non-autistic peers. Establishing how effective interventions are for improving social functioning is important to help inform what should be offered to children with autism. This study reviewed how effective interventions that involved interaction with a live animal, known as animal-assisted interventions, are in improving social functioning in children with autism. A systematic search of the evidence on this topic found nine studies, which were explored for the effectiveness of animal-assisted interventions and the quality of methods used. Overall, these studies showed improvements in social functioning following equine-assisted or therapeutic horse-riding interventions, with initial evidence showing improvements are sustained in the short and medium term. However, several issues were identified, which limit the strength of any conclusions that can be drawn from this evidence. For example, in many studies people assessing the children were aware that they received the intervention or were in a control group. There was also not enough evidence available to draw conclusions on the effectiveness of other animal-assisted interventions. Future research should address the limitations that were common in the designs of these studies and investigate the potential benefit of other animal populations, such as dogs and cats.
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The Animals and Society Institute facilitates an annual interdisciplinary meeting of emerging scholars from around the world, encouraging attendees to interrogate what it means to be a scholar, with an emphasis on animal studies within our respective disciplines. In that vein, we assess what it means to be an emerging animal-studies scholar in three interconnected but distinct academic disciplines: anthropology, sociology, and social work. We elaborate on three dominant themes: (1) the place of animals or the “animal turn”; (2) our subjectivity and how we find unorthodox networks or what Donna Haraway refers to as our “oddkin”; (3) and our inherent roles as interdisciplinary scholars and the liminal positions we occupy, as we address complex social problems like climate change. By reflecting on how we have encountered barriers and overly strict binaries collectively and as individuals, we can begin to deconstruct these obstacles and create opportunities.
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A 10-month prospective study was carried out which examined changes in behaviour and health status in 71 adult subjects following the acquisition of a new pet (either dogs or cats). A group of 26 subjects without pets served as a comparison over the same period. Both pet-owning groups reported a highly significant reduction in minor health problems during the first month following pet acquisition, and this effect was sustained in dog owners through to 10 months. The pet-acquiring groups also showed improvements in their scores on the 30-item General Health Questionnaire over the first 6 months and, in dog owners, this improvement was maintained until 10 months. In addition, dog owners took considerably more physical exercise while walking their dogs than the other two groups, and this effect continued throughout the period of study. The group without pets exhibited no statistically significant changes in health or behaviour, apart from a small increase in recreational walking. The results provide evidence that pet acquisition may have positive effects on human health and behaviour, and that in some cases these effects are relatively long term.
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Variations in maternal care affect the development of individual differences in neuroendocrine responses to stress in rats. As adults, the offspring of mothers that exhibited more licking and grooming of pups during the first 10 days of life showed reduced plasma adrenocorticotropic hormone and corticosterone responses to acute stress, increased hippocampal glucocorticoid receptor messenger RNA expression, enhanced glucocorticoid feedback sensitivity, and decreased levels of hypothalamic corticotropin-releasing hormone messenger RNA. Each measure was significantly correlated with the frequency of maternal licking and grooming (all r's > −0.6). These findings suggest that maternal behavior serves to “program” hypothalamic-pituitary-adrenal responses to stress in the offspring.
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Oxytocin (OT) is a neuropeptide increasingly recognized for its role in bonding, socialization, and stress relief. Previous research has demonstrated participants' OT levels increased after interacting with or petting a dog, suggesting OT is at least partially responsible for the calm, relaxing feeling that participants experienced during this intervention. The purpose of our study was to more closely examine changes in oxytocin levels in men and women in response to interaction with their own dog after being separated from the dog while at work all day. This condition was compared with a reading control condition, without the presence of the dog. Because the workplace is a common stressor, participants were examined after work to evaluate how interacting with a pet may help decrease stress, as evidenced by increases in serum oxytocin levels. Ten men and ten women participated in the study. Serum oxytocin levels were obtained before the participants had contact with their dogs and then again after 25 minutes of interaction with their dog. The same protocol was followed for the reading condition except that instead of interacting with their dog, participants read nonfiction materials selected by the researchers. Serum oxytocin levels increased statistically more for women who interacted with their dog when compared with women in the reading condition (p = 0.003). There was no significant increase in oxytocin level in men after interaction with the bonded dog compared with the reading condition; in fact, male oxytocin levels decreased after both the dog and reading conditions. These results suggest that men and women may have different hormonal responses to interaction with their dogs. It is unclear to what degree OT reactivity was affected by hormones, personality traits, or interpersonal relationships; factors which warrant further research.
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Massage-like stroking induces acute antinociceptive effects that can be reversed by an oxytocin antagonist, indicating activation of oxytocin on endogenous pain controlling systems. We now demonstrate an increase in hindpaw withdrawal latencies (HWLs), in response to thermal and mechanical stimuli, which was present after six treatments of massage-like stroking every other day and which continued to increase through the remaining seven treatments. Repeated massage-like stroking also resulted in increased oxytocin-like immunoreactivity (oxytocin-LI) levels in plasma and periaquaductal grey matter (PAG). Furthermore, increases in HWLs were also present after injections of oxytocin into the PAG (0.1, 0.5 and 1.0 nmol). Intra-PAG oxytocin injection of 1 nmol followed by 1 or 20 nmol of naloxone attenuated the increments in HWL. Also, there was a dose-dependent attenuation of the oxytocin-induced antinociceptive effects following intra-PAG injection of the µ-opioid antagonist β-funaltrexamine (β-FNA) and the κ-opioid antagonist nor-binaltorphimine (nor-BNI) but not the δ-antagonist naltrindole. The long-term antinociceptive effects of massage-like stroking may be attributed, at least partly, to the oxytocinergic system and its interaction with the opioid system, especially the µ- and the κ-receptors in the PAG.
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The aim of the present investigation was to explore whether the personality characteristics of women who have recently given birth differ from those of a control group of similar aged women and if so, whether such deviations are related to the pregnancy- and lactation-associated hormones oxytocin and prolactin which in animal experiments have been shown to play a role in maternal behavior. Thereforethe Karolinska Scales of Personality (KSP) were used in 50 women 4 days postpartum and in addition 18 blood samples were drawn in connection with breastfeeding. Oxytocin and prolactin levels were measured by radioimmunoassay. The women investigated scored lower in Muscular Tension (p < 0.05), in Monotony Avoidance (p < 0.001) and Psychasthenia (p < 0.01) and higher in Social Desirability (p < 0.001) than a reference material. Plasma levels of oxytocin and prolactin rose as expected in response to breastfeeding. When the average prolactin and oxytocin levels obtained at the 18 different timepoints of each woman were correlated with the scores obtained in the various KSP items, some significant relationships were found. Significant positive correlations were found between prolactin and the KSP dimensions Social Desirability and Inhibited Aggression and negative correlations with Psychasthenia. Significant inverse relationships between oxytocin and several Anxiety and Aggression variables, Guilt in particular, were also found. Correlations with oxytocin and prolactin levels were as a rule particularly clear in samples collected during breastfeeding. The data obtained are discussed from a biological point of view in relation to the specific 'maternal behavior' described in other mammals. It is suggested that subtle psychological and behavioral changes occur in women during motherhood and that these changes may in part be related to prolactin and oxytocin.
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To test the idea that dogs have a positive influence on the social behavior of school children, one of three dogs was introduced alternately into a class at an elementary school in Vienna, attended by 24 children (mean age: 6.7 years). Most of the 14 boys and ten girls came from first-generation immigrant families. With parental consent, their behavior was videotaped for two hours every week, during “open teaching situations,” first during a one-month control period in the absence of dogs, followed by an experimental period of similar duration, when a dog was present in the classroom. Frequency and duration of all observable behaviors of individuals and their interactions were coded from these tapes. Although major individual differences were found in the children's interest in the dog and their behavioral responses, the group became socially more homogenous due to decreased behavioral extremes, such as aggressiveness and hyperactivity; also, formerly withdrawn individuals became socially more integrated. Effects were more pronounced in the boys than the girls. Even though the children spent considerable time watching and making contacting with the dog, they also paid more attention to the teacher. We conclude that the presence of a dog in a classroom could positively stimulate social cohesion in children and provide a relatively cheap and easy means of improving teaching conditions.
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This study examined the effects of the presence of a dog in the classroom on field independence, social competence, empathy with animals and social-emotional atmosphere. The participants were 46 first-graders (43 of them immigrants) of two school classes (control and experimental). In the experimental group, a dog was present in the classroom for three months. Multivariate analyses revealed significant enhancement of field independence and empathy with animals in the experimental group in comparison to the control group (no dog). Thus, the presence of the dog fostered the development of autonomous functioning and a better segregation of self/non-self, which is the foundation of sensitivity towards the needs and moods of other people. Moreover, according to the views of the teachers, the children in the experimental group exhibited higher social integration, and there were fewer aggressive children, compared with the children in the control group. In sum, the results indicate that a dog can be an important factor in the social and cognitive development of children.
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The specific aim of the present study was to determine if stroking in conscious rats can influence spontaneous locomotor behavior in an open-field arena. For this purpose, conscious rats were held across the scapula and the ventral side of the abdomen was stroked at a pressure of 100–150 mm H2O and at a speed of approximately 20 cm/s. The stimulation frequency was approximately 40 strokes/min and the duration 2, 5, and 10 min. Animals held for 10 min served as controls. There was a significant decrease in rearing and locomotion and a significant increase in peripheral activity in the open-field arena after the treatment. Maximal effects were obtained after 5 min of stroking. These effects were consistent with a stroking-induced sedative effect similar to that seen in this open-field arena model following neuroleptics or large doses of oxytocin.
Article
The aim of this study was to determine how massage-like stroking of the abdomen in rats influences arterial blood pressure. The participation of oxytocinergic mechanisms in this effect was also investigated. The ventral and/or lateral sides of the abdomen were stroked at a speed of 20 cm/s with a frequency of 0.017–0.67 Hz in pentobarbital anesthetized, artificially ventilated rats. Arterial blood pressure was recorded with a pressure transducer via a catheter in the carotid artery. Stroking of the ventral, or both ventral and lateral sides of the abdomen for 1 min with a frequency of 0.67 Hz caused a marked decrease in arterial blood pressure (approx. 50 mmHg). After cessation of the stimulation blood pressure returned to the control level within 1 min. The maximum decrease in blood pressure was achieved at frequencies of 0.083 Hz or more. Stroking only the lateral sides of the abdomen elicited a significantly smaller decrease in blood pressure (approx. 30 mmHg decrease) than stroking the ventral side. The decrease in blood pressure caused by stroking was not altered by s.c. administration of an oxytocin antagonist (1-deamino-2-d-Tyr-(Oet)-4-Thr-8-Orn-oxytocin, 1 mg/kg) directed against the uterine receptor. In contrast, the administration of 0.1 mg/kg of oxytocin diminished the effect, which was antagonized by a simultaneous injection of the oxytocin antagonist. These results indicate that the massage-like stroking of the abdomen decreases blood pressure in anesthetized rats. This effect does not involve intrinsic oxytocinergic transmission. However, since exogenously applied oxytocin was found to diminish the effect of stroking, oxytocin may exert an inhibitory modulatory effect on this reflex arc.
Article
The objective of this study was to investigate how sensory stimulation by massage-like stroking influences blood pressure and heart rate in conscious rats. Also, the influence of different locations and durations of the stimulation were assessed. For this purpose, the ventral side of the abdomen or the dorsal side of the back was manually stroked at a speed of approximately 20 cm/s, with a frequency of 0.67 Hz and at an estimated pressure of 100 mm H2O. During the treatment, the rats were held across the scapula and the neck region. Blood pressure and heart rate were measured with the cuff technique before treatment and repeatedly during the post-stimulatory period. Massage-like stroking for 5 min of the abdominal area produced a maximum decrease of approximately 20 mm Hg in blood pressure and 60 beats/min in heart rate. This reduction remained significant at 3 and 4 h after stimulation, respectively. Stimulation of the abdominal area for 2 min produced a less pronounced decrease in blood pressure as compared to the 5-min stroking. Stroking of the back resulted in a short-lasting blood pressure increase that gradually returned to the baseline level within the post-stimulatory observation time. Control animals that were handled in the same way as the experimental animals except for the stroking showed an increase of approximately 20 mm Hg in blood pressure and 60 beats/min for about 1 h after the cessation of the handling. The responses of the blood pressure and heart rate to both abdominal and back massage were significantly inhibited as compared to the control animals. These results suggest that massage-like stroking of the skin produces an inhibitory effect on the cardiovascular excitatory responses in rats. Especially, the results of the present study demonstrate that massage-like stroking of the abdomen reduces both blood pressure and heart rate below the pre-stimulus baseline levels.