Glucocorticoid response to naturalistic interactions between children and dogs.

Although research has shown that pets appear to provide certain types of social support to children, little is known about the physiological bases of these effects, especially in naturalistic contexts. In this study, we investigated the effect of free-form interactions between children (ages 8-10 years) and dogs on salivary cortisol concentrations in both species. We further investigated the role of the child-dog relationship by comparing interactions with the child's pet dog to interactions with an unfamiliar dog or a nonsocial control condition, and modeled associations between survey measures of the human-animal bond and children's physiological responses. In both children and dogs, salivary cortisol decreased from pre- to post-interaction; the effect was strongest for children interacting with an unfamiliar dog (compared to their pet dog) and for the pet dogs (compared to the unfamiliar dog). We found minimal evidence for associations between cortisol output and behaviors coded from video, but children scoring higher on survey measures of the human-animal bond exhibited the greatest reductions in cortisol when interacting with dogs. Self-reported loneliness was not related to cortisol or the human-animal bond, but measures of both loneliness and the human-animal bond were higher among children who participated after the onset of the COVID-19 pandemic, relative to those who participated before the pandemic. This study builds on previous work that investigated potential stress-buffering effects of human-animal interaction during explicit stressors and demonstrates important physiological correlates of naturalistic interactions between children and dogs, similar to those that occur in daily life.

A comparative evaluation of the role of olfaction in attachment.

Olfactory information plays an important role in the attachment and bonding processes for both humans and non-human animals. Odor cues obtained via individual body odor facilitate attachment and bonding processes across species with regard to both mate selection and mother-infant bonding. The purpose of the present paper is to summarize the role of odor as it pertains to bond formation and maintenance in the mother-infant bond for human infants and non-human animal infants, and for mate selection among human adults and non-human animals. We then synthesize this summary with literature on attachment and existing evidence for the relationships between olfaction and attachment processes. Finally, we suggest avenues for areas of future research.

Dogs distinguish authentic human emotions without being empathic.

Several recent studies have investigated how dogs perceive human emotional expressions. They have measured the reactions of dogs when exposed to stimuli presented in different modalities, such as photographs, audio recordings or odor samples, or to humans simulating various emotional situations. In the current study, dog owners were manipulated to genuinely experience emotions of happiness, sadness, and neutrality. We measured how dogs responded to their owners' authentic emotions in two different natural situations: induction of the emotion through a video clip and training of a new task. Through a detailed analysis of dog behavior in these naturalistic settings, we investigated whether dogs show behavioral responses to genuine human emotions. We found that dogs behaved differently depending on the owner's emotional state: they gazed and jumped less at owners when they were sad, and their compliance with the 'sit' command was also diminished. When owners were happy, dogs performed better in the trained task. These results are discussed in light of how dogs perceive human emotional expressions and the adaptive value of this skill.

Many faces of dominance: the manifestation of cohabiting companion dogs' rank in competitive and non-competitive scenarios.

There are indications that companion dogs of multi-dog households form a hierarchy, maintained by formal and agonistic dominance. Although it was found that the behaviour of dogs depends on their rank in several contexts, so far, the assessment of their rank itself has been based on owner-completed questionnaires. With this research we endeavoured to find associations between rank scores from the Dog Rank Assessment Questionnaire (DRA-Q) and cohabiting dogs' behaviour in a competitive test (Toy Possession test-32 dog pairs) and a non-competitive, citizen science scenario (Greeting test-20 dog pairs). Based on the grabbing the toy first and keeping the toy at the end variables, the dogs' rank score provided a reliable indication of the dominant and subordinate dogs' behaviour in the Toy Possession test. Similarly, the occurrence of dominant and submissive behaviours in the Greeting Test showed a good match with the agonistic and leadership subscores of the composite rank score from the DRA-Q. Our results provide a pioneering case for validating a questionnaire-based rank scoring method with biologically meaningful behavioural tests in the case of companion dogs. The finer analysis of the results highlighted that in the case of a multi-question scoring system, some components might provide more effective prediction of the dogs' rank-related behaviour in some situations, while other components are more relevant in others, with traits related to agonistic dominance having relevance across contexts.

Pet ownership and psychosocial outcomes among the oldest old in Germany during the Covid-19 pandemic. Findings based on the nationally representative "Old Age in Germany (D80+)".

OBJECTIVES: To examine the association between pet ownership and psychosocial outcomes among the oldest old in Germany during the Covid-19 pandemic. METHODS/DESIGN: Data from the "Old Age in Germany (D80+)" study were used, a large, nationwide representative study covering both individuals living at home and individuals in nursing homes aged 80 years and above (n = 2867 individuals). The telephone interviews were conducted from May to October 2021. Established tools (e.g., "Short Form of the Depression in Old Age Scale", DIA-S4) were used to quantify the outcomes. Five groups were generated: (1) no pet ownership, (2) having at least one dog (but no other pets), (3) having at least one cat (but no other pets), (4) having at least one other pet (but neither dogs nor cats), (5) having at least two different types of pets (in any combination). RESULTS: Multiple linear regressions showed that compared to individuals without a pet, individuals having at least one dog had significantly lower loneliness levels (ß = -0.21, p < 0.01). In the fully-adjusted models, other forms of pet ownership were not significantly associated with the outcomes examined. CONCLUSION: Particularly living with a dog was associated with lower loneliness among the oldest old people in Germany. If living with a dog is in line with the preferences and attitudes of the very old, this could be a strategy for reducing loneliness in this age group.

Exploring frailty in apparently healthy senior dogs: a cross-sectional study.

BACKGROUND: As dogs age, they face various health challenges, and preventive care may be overlooked, impacting their quality of life. Frailty, a concept established in human medicine, has recently been applied to dogs using validated tools like the frailty index and frailty phenotype. This study aims to characterize frailty in senior pet dogs and investigate associated factors. To achieve this goal, 88 apparently healthy dogs, as reported by their owners, voluntarily participated in thorough consultations. These consultations included supplementary examinations such as urinary analyses, hematological assessments, and blood biochemistry. Additionally, owners completed questionnaires addressing their dog's overall health, cognitive and locomotor status, as well as their own attachment to the dog and personality traits. Subsequently, each dog was classified as robust or frail based on the presence of multiple criteria out of a set of five. All collected data underwent preliminary screening by a multiple factorial analysis, followed by binomial logistic regression to model frailty. RESULTS: The final population consisted of 74 dogs, with a frailty prevalence of 41.9% (95% CI: 30.5 - 53.9). In the statistical analysis, older age of the dog, lower owner attachment score, lack of regular deworming, and a disparity in extraversion between owner and dog were identified as contributing factors to frailty. CONCLUSIONS: This study emphasizes the importance of regular deworming and strong owner-pet attachment in reducing frailty in dogs. It underscores the significance of proactive pet care and highlights the complex relationship between owner-dog personalities and canine frailty. This research advocates for a holistic approach that considers both human and canine traits to promote better health outcomes.

Walk or be walked by the dog? The attachment role.

BACKGROUND: The human-animal bond has been recognized as having positive effects on the health and well-being of both humans and pets. The present study aims to explore the influence of attachment on physical activity (PA), lifestyle, and health outcomes of dog owners (DO), highlighting the mutual benefits resulting from the relationship between DO and dogs. METHODS: Thirty-eight DO and their dogs participated in this study. Socio-demographic data, the Self-Rated Health (SRH), FANTASTICO Lifestyle Scale, and the Lexington Attachment Pet Scale (LAPS) were assessed. PA was measured in both the DO and the dogs, using an ActiGraph GT3X accelerometer in the context of daily routine. Descriptive statistics and Spearman rank correlation analyses were performed to examine the associations between LAPS, PA levels, socio-demographic variables, lifestyle behaviors, and SRH. RESULTS: Significant correlations were found between the dog owners' light-level PA and the pets' vigorous level of PA (rho = 0.445, p = 0.01). Furthermore, the importance of the pets' health (rho = -0.785, p = 0.02) and the LAPS subscales, namely proximity (rho = 0.358, p = 0.03), and attachment (rho = 0.392, p = 0.01), were related to taking the pet for a walk. Regarding lifestyle, DO with a healthier lifestyle had a better self-assessment of their health using the SRH (rho = 0.39, p = 0.02). Moreover, DO with better lifestyles also exhibited greater concern for their pet's health (rho = 0.398, p = 0.01). CONCLUSIONS: This study emphasizes that individuals who adopt healthier habits tend to perceive themselves as healthier and exhibit greater concern for their pets' health. The attachment between DO and dogs is important in promoting healthy lifestyle behaviors and engagement in PA. Our results highlight that the presence of a dog is associated with a higher level of PA in DO, depending on the strength of the human-animal bond.

Companion animals and child development outcomes: longitudinal and cross-sectional analysis of a UK birth cohort study.

BACKGROUND: Research into the impact of social relationships on childhood and adolescent health and wellbeing has been largely limited to children's relationships with other humans, while studies into the impact of pet ownership are sparse and have generally not adjusted for potential confounders. This study aimed to investigate the association between pet ownership and a range of developmental outcomes in childhood and adolescence. METHODS: Data were self-reports and direct assessments of approx. 14,000 children from the Avon Longitudinal Study of Parents and Children (ALSPAC). Multivariable regression models adjusting for confounding factors examined associations between developmental outcome measures (emotional health, behavioural development, cognitive development, language development, educational attainment) and concurrent pet ownership, including species, and also longitudinal pet ownership history and pet-interaction where possible. Analyses model numbers using multiple imputation varied from n = 393-8963. RESULTS: In cross-sectional analyses, owning a dog (b = 0.24, [0.06-0.41], p = .004) and owning other/miscellaneous pets (b = 0.18, [0.03-0.33], p = .021) at age 3 were associated with higher prosocial behaviour score. Owning a pet was associated with a higher non-verbal communication score at age 2 (cross-sectional, b = 0.18, [0.04-0.32], p = .014), and a higher language development score at age 5 (cross-sectional, b = 1.01, [0.18-1.83], p = .017). However, pet ownership was associated with lower educational attainment across a number of academic subjects and timepoints, in both cross-sectional and longitudinal analyses. It was also cross-sectionally linked to hyperactivity at age 3 and conduct problems at age 3 and 11. Furthermore, at age 8, cross-sectional analysis showed that children who owned any pets (OR [95% CI]: 0.85 [0.73-0.98], p= ·026) or cats (0.83, [0.73-0.95], p= ·006) had lower odds of high self-esteem (scholastic competence). CONCLUSIONS: Using a large, well-designed longitudinal study and adjusting for key confounders, we found little evidence of cross-sectional or longitudinal associations between pet ownership and emotional health or cognitive outcomes in children. There may, however, be some cross-sectional and longitudinal association with poorer educational attainment and a positive impact on social interactions as seen through associations with enhanced language development and prosocial behaviour. This study demonstrates the importance of adjustment for confounding variables and suggests that, contrary to popular belief, positive impacts of pet ownership on childhood development may be mainly limited to social behaviour and language development.

Keeper effect: Animals are more active in the presence of their caretakers.

Zookeepers are the primary caretakers of animals, providing daily care through frequent and close interactions. From the animal's perspective, most of these daily interactions are likely to have positive outcomes. With consistent and reliable interactions, a human-animal relationship is expected to develop. Our aim of this study was to investigate if the presence of the primary keeper in the public viewing area of zoo exhibits impacts the behavior of animals. We observed the behavior of 15 individuals of six species in the presence and absence of their primary keeper. Overall, we observed animals being more active in their keeper's presence than when the keeper was not present. When we considered if the keeper was nearby around times of offered opportunities to animals (e.g., feeding, enrichment, and training), our results showed that animals were equally as active when the keeper was present before an opportunity and when no opportunity was offered. These equal activity levels imply that the keeper is a cue for a forthcoming event to the animals, which reflects anticipatory behavior. Overall, we demonstrate that keeper presence is an environmental context in which animals behave differently than in keeper absence.

Behavioural synchronization and social referencing of dogs and humans: walking in dyad vs in group.

Recent studies have demonstrated that dogs synchronize their locomotor behaviour with that of their owners. The present study aims to improve our understanding of the sensorimotor processes underlying interspecific behavioural synchronization by testing the influence of the number of humans on dogs' behavioural synchronization. We used Global Positioning System (GPS) devices in an outdoor environment to measure dogs' behavioural synchronization to humans during a locomotor activity involving three speeds (static, slow walking and fast walking). For half of the dogs, only their owner was walking, while for the other half, the owner walked with two familiar people. We also tested the effect of dog breeds by involving 30 shepherd dogs and 30 molossoids. Our results showed that dogs exhibited the same level of behavioural synchronization with their owner if alone or if surrounded by two familiar people. Though the presence of a group of humans did not strengthen the dogs' locomotor synchronization, it did produce another effect: dogs gazed at their owners more frequently in the presence of a group compared to their owner alone. This result suggests the same level of locomotor social entrainment but a difference in social referencing depending on the number of humans.

Pet dogs (Canis familiaris) re-engage humans after joint activity.

Joint intentionality, the mutual understanding of shared goals or actions to partake in a common task, is considered an essential building block of theory of mind in humans. Domesticated dogs are unusually adept at comprehending human social cues and cooperating with humans, making it possible that they possess behavioral signatures of joint intentionality in interactions with humans. Horschler and colleagues (Anim Behav 183: 159-168, 2022) examined joint intentionality in a service dog population, finding that upon interruption of a joint experience, dogs preferentially re-engaged their former partner over a passive bystander, a behavior argued to be a signature of joint intentionality in human children. In the current study, we aimed to replicate and extend these results in pet dogs. One familiar person played with the dog and then abruptly stopped. We examined if dogs would preferentially re-engage the player instead of a familiar bystander who was also present. Consistent with the findings of Horschler and colleagues (Anim Behav 183: 159-168, 2022), pet dogs preferentially gazed toward and offered the toy to the player significantly more than the familiar bystander. However, no difference was observed in physical contact. These findings provide preliminary evidence for behavioral signatures of joint intentionality in pet dogs, but future work is needed to understand whether this phenomenon extends to other contexts.

Does Pet Parenting Style predict the social and problem-solving behavior of pet dogs (Canis lupus familiaris)?

The behavior and cognition of pet domestic dogs (Canis lupus familiaris) has drawn increasing scientific attention over the last several decades. One area of focus has been the influence of lifetime variables, including the home environment and prior experiences, on the social and problem-solving behavior of dogs. While the human-dog relationship has become an important area of study, only a few studies have empirically investigated how the quality of that relationship may influence a dog's performance on behavioral or cognitive tasks. In the current study, we asked if a human caretaker's self-reported expectations and patterns of responding towards their dog (Pet Parenting Style) would predict the dog's social and problem-solving behavior. Owners who had previously been asked to complete a Pet Parenting Style survey were later invited to have their dogs participate in three behavioral tests: The Secure Base Test, a Sociability Test and the Solvable Task. Consistent with the human development literature, results indicated that Pet Parenting Styles did predict patterns of dog behavior and cognition on these tests. On average, dogs with authoritative owners (high expectations, high responsiveness) had the highest rate of secure attachment, were highly social, sensitive to social context and were more persistent and successful on the problem-solving task than dogs with authoritarian owners (high expectations and low responsiveness) and permissive owners (low expectations, low responsiveness). These findings suggest that the quality and style of individual dog-human relationships, including Pet Parenting Style, may be relevant when evaluating and interpreting outcomes of canine cognition research.

When the owner does not know: comparing puppies and adult dogs' showing behavior.

Domestic dogs have been shown to engage in interspecific communication with their owners using a flexible repertoire of signals (i.e., gaze, vocalizations, and postures). This ability is influenced by ontogenetic development as well as breed selection. Different aspects of this phenomenon have been studied using the out of reach/hidden object task in which a piece of food is shown to the dog and then hidden in an unreachable spot by the experimenter. Dogs' behavioral displays toward the target and the owner (ignorant about the location of the food) have been observed. The complex communicative behavior dogs exhibit in this context is defined as showing behavior and includes attention-getting components directed toward the owner, and directional components directed toward the target. No study has investigated the ontogenetic development of this behavior. In the current study, we compared the showing behavior in 4-6 month old puppies and 2-11 year old adults in an out of reach task involving the hiding of a food reward in one of two cabinets. Dogs were exposed to three conditions: (1) Owner with Food (OF), (2) Owner No Food (ONF), and (3) Alone with food (AF). Dogs showed more gaze alternations when both the food and the owner were present confirming the intentional and referential nature of this behavior. Contrary to our expectations, we found no differences between the showing behaviors of 4-6 month old puppies and adult dogs. This study provides interesting preliminary evidence of showing behavior in puppies. Further studies are needed to gain a deeper understanding of the factors influencing this communicative behavior (i.e., breed, level of training). Furthermore, longitudinal studies should be performed from the age of 2 months up to 1 and 2 years to better clarify the influence of development and experience on showing behavior in domestic dogs.

Discrimination of cat-directed speech from human-directed speech in a population of indoor companion cats (Felis catus).

In contemporary western cultures, most humans talk to their pet companions. Speech register addressed to companion animals shares common features with speech addressed to young children, which are distinct from the typical adult-directed speech (ADS). The way dogs respond to dog-directed speech (DDS) has raised scientists' interest. In contrast, much less is known about how cats perceive and respond to cat-directed speech (CDS). The primary aim of this study was to evaluate whether cats are more responsive to CDS than ADS. Secondarily, we seek to examine if the cats' responses to human vocal stimuli would differ when it was elicited by their owner or by a stranger. We performed playback experiments and tested a cohort of 16 companion cats in a habituation-dishabituation paradigm, which allows for the measurement of subjects' reactions without extensive training. Here, we report new findings that cats can discriminate speech specifically addressed to them from speech addressed to adult humans, when sentences are uttered by their owners. When hearing sentences uttered by strangers, cats did not appear to discriminate between ADS and CDS. These findings bring a new dimension to the consideration of human-cat relationship, as they imply the development of a particular communication into human-cat dyads, that relies upon experience. We discuss these new findings in the light of recent literature investigating cats' sociocognitive abilities and human-cat attachment. Our results highlight the importance of one-to-one relationships for cats, reinforcing recent literature regarding the ability for cats and humans to form strong bonds.

Still-face effect in domestic dogs: comparing untrained with trained and animal assisted interventions dogs.

The still-face effect has been extensively studied in human infants and comprises the reduction in affiliative behaviors and increased stress that occurs after a sudden interruption of social interaction with a caregiver. Domestic dogs (Canis familiaris) are model candidates for showing this effect, as they form deep bonds with their owners and interspecific social interaction is reinforcing to them. The aim of these studies was to assess if companion dogs exhibit the still-face effect and whether prior experiences during ontogeny modulate this effect. To this end, Study 1 compared dogs with different levels of training (untrained, intermediate, and advanced), while Study 2 assessed dogs that participated in Animal Assisted Interventions (AAIs) and companion dogs (CDs). The procedure was carried out virtually and comprised three phases lasting 1 min: interaction, still-face (the owner turned suddenly indifferent), and reunion (the interaction was resumed). Dogs exhibited a decrease in proximity to and contact with the owner, as well as an increase in begging and stress behaviors during the still-face phase. Moreover, this was not observed in a control condition in which the interaction continued in the same way during all three phases, discarding alternative explanations for these changes. These results show that dogs experience a still-face effect in a similar way to infants, highlighting the value interspecific social interaction has for dogs. Nevertheless, the absence of differences according to their training level or participation in AAIs suggests this is a robust phenomenon, which appears to be less susceptible to the influences of ontogenetic experiences.

Breed group differences in the unsolvable problem task: herding dogs prefer their owner, while solitary hunting dogs seek stranger proximity.

The communicating skills of dogs are well documented and especially their contact-seeking behaviours towards humans. The aim of this study was to use the unsolvable problem paradigm to investigate differences between breed groups in their contact-seeking behaviours towards their owner and a stranger. Twenty-four dogs of ancient breeds, 58 herding dogs, and 17 solitary hunting dogs were included in the study, and their behaviour when presented with an unsolvable problem task (UPT) was recorded for 3 min. All breed groups interacted with the test apparatus the same amount of time, but the herding dogs showed a longer gaze duration towards their owner compared to the other groups and they also preferred to interact with their owner instead of a stranger. Interestingly, the solitary hunting dogs were more in stranger proximity than the other groups, and they also showed a preference to make contact with a stranger instead of their owner. Hence, we found differences in contact-seeking behaviours, reflecting the dog-human relationship, between breed groups that might not only be related to their genetic similarity to wolves, but also due to the specific breeding history of the dogs.

Is this love? Sex differences in dog-owner attachment behavior suggest similarities with adult human bonds.

Sex differences in the behavioral responses of Labrador Retriever dogs in the Strange Situation Test were explored. Behaviors expressed by dogs during seven 3-min episodes were analyzed through a Principal Component Analysis (PCA). The scores of factors obtained were analyzed with a Generalized Linear Mixed Model to reveal the effects of the dog's sex and age and the owner's sex. In Episode 1 (dog and owner) and 5 (dog alone), the PCA identified three and two factors, respectively, which overall explained 68.7% and 59.8% of the variance, with no effect of sex. In Episodes 2 (dog, owner, and stranger), 3 and 6 (dog and stranger), and 4 and 7 (dog and owner), the PCA identified four factors, which overall explained 51.0% of the variance. Effects of sex were found on: Factor 1 (distress), with lower scores obtained by females in Episode 2 and higher in Episode 3; Factor 2 (sociability), which was overall higher in females; Factor 3 (separation-distress), with females, but not males, obtaining higher scores when left with the stranger than when with the owner. Therefore, females were overall more social but seemed more affected than males by the owner's absence. Parallels can be traced between our results and sex differences found in adult human romantic attachment, suggesting that the dog-owner bond has characteristics that are not found in the infant-mother relationship.

Evolution of facial muscle anatomy in dogs.

Domestication shaped wolves into dogs and transformed both their behavior and their anatomy. Here we show that, in only 33,000 y, domestication transformed the facial muscle anatomy of dogs specifically for facial communication with humans. Based on dissections of dog and wolf heads, we show that the levator anguli oculi medialis, a muscle responsible for raising the inner eyebrow intensely, is uniformly present in dogs but not in wolves. Behavioral data, collected from dogs and wolves, show that dogs produce the eyebrow movement significantly more often and with higher intensity than wolves do, with highest-intensity movements produced exclusively by dogs. Interestingly, this movement increases paedomorphism and resembles an expression that humans produce when sad, so its production in dogs may trigger a nurturing response in humans. We hypothesize that dogs with expressive eyebrows had a selection advantage and that "puppy dog eyes" are the result of selection based on humans' preferences.

Affective Recommender System for Pet Social Network.

In this new era, it is no longer impossible to create a smart home environment around the household. Moreover, users are not limited to humans but also include pets such as dogs. Dogs need long-term close companionship with their owners; however, owners may occasionally need to be away from home for extended periods of time and can only monitor their dogs' behaviors through home security cameras. Some dogs are sensitive and may develop separation anxiety, which can lead to disruptive behavior. Therefore, a novel smart home solution with an affective recommendation module is proposed by developing: (1) an application to predict the behavior of dogs and, (2) a communication platform using smartphones to connect with dog friends from different households. To predict the dogs' behaviors, the dog emotion recognition and dog barking recognition methods are performed. The ResNet model and the sequential model are implemented to recognize dog emotions and dog barks. The weighted average is proposed to combine the prediction value of dog emotion and dog bark to improve the prediction output. Subsequently, the prediction output is forwarded to a recommendation module to respond to the dogs' conditions. On the other hand, the Real-Time Messaging Protocol (RTMP) server is implemented as a platform to contact a dog's friends on a list to interact with each other. Various tests were carried out and the proposed weighted average led to an improvement in the prediction accuracy. Additionally, the proposed communication platform using basic smartphones has successfully established the connection between dog friends.

Military Dogs and Their Soldier Companions: The More-than-human Biopolitics of Leishmaniasis in Conflict-torn Colombia.

Cutaneous leishmaniasis is a vector-borne disease that produces growing skin ulcers. In Colombia, the transmitting phlebotomine sandfly is native to the same jungles that have been the primary theater of war. Although combatants are the most affected by leishmaniasis, military landmine detection dogs are also significantly impacted. This article draws on ethnographic field research with human and canine members of the Colombian military. While their leishmaniasis ulcers constitute a shared expression of violence that makes evident the closeness of the human-dog bond, differences in their state-provided health care reveal the production of shifting species hierarchies. I argue that war scrambles both human-dog affective relationships and biopolitically configured interspecies hierarchies in ways that produce suffering, not just for humans and dogs separately, but also for the bonds they forge together. Building peace through health care demands repairing the ways in which armed violence has rendered the bonds between humans and nonhumans pathological.