Communication in Dogs

Mapping of the exterior architecture of the mesocephalic canine brain

Despite extensive studies published on the canine brain, inconsistencies and disagreements in the nomenclature and representation of various cerebral structures continue to exist. This study aimed to create a comprehensive mapping of the external architecture of the mesocephalic canine brain with a focus on the major gyri and sulci. Standardized dissection techniques were used on 20 ethically sourced brains obtained from 6 to 10-year-old dogs that were free of neurological disorders. Distinct gyri and sulci with unique locations and bordering structures were observed. Thus, it was possible to identify the often-ignored subprorean gyrus. In addition, this study was able to illustrate the unique locations and bordering structures of gyri and sulci. The findings can contribute to a consensus among researchers on the canine brain anatomy and assist in clarifying the inconsistencies in cerebral structure representation. Furthermore, the results of this study may hold significant implications for veterinary medicine and neuroscience and serve as a foundation for the development of diagnostic and therapeutic approaches for various neurological diseases in dogs. Our findings offer valuable insights into the unique evolutionary adaptations and specialized behaviors of the canine brain, thereby increasing awareness about the neural structures that enable dogs to demonstrate their unique traits.

The odour of an unfamiliar stressed or relaxed person affects dogs' responses to a cognitive bias test

Dogs can discriminate stressed from non-stressed human odour samples, but the effect on their cognition is unstudied. Using a cognitive bias task, we tested how human odours affect dogs' likelihood of approaching a food bowl placed at three ambiguous locations ("near-positive", "middle" and "near-negative") between trained "positive" (rewarded) and "negative" (unrewarded) locations. Using odour samples collected from three unfamiliar volunteers during stressful and relaxing activities, we tested eighteen dogs under three conditions: no odour, stress odour and relaxed odour, with the order of test odours counterbalanced across dogs. When exposed to stress odour during session three, dogs were significantly less likely to approach a bowl placed at one of the three ambiguous locations (near-negative) compared to no odour, indicating possible risk-reduction behaviours in response to the smell of human stress. Dogs' learning of trained positive and negative locations improved with repeated testing and was significant between sessions two and three only when exposed to stress odour during session three, suggesting odour influenced learning. This is the first study to show that without visual or auditory cues, olfactory cues of human stress may affect dogs' cognition and learning, which, if true, could have important consequences for dog welfare and working performance.

Preliminary Study of Scent Rolling in Captive Wolves (Canis lupus L. 1758) in Response to Olfactory Enrichment

Scent rolling, a behaviour observed in various large carnivores like wolves, entails the animal lowering its chin and neck towards a scent, followed by rubbing the head, neck, shoulders, and back into it. This behaviour is prevalent among wolves exposed to diverse scents, though its exact purpose remains uncertain. In this study, captive wolves at Osijek Zoo responded differently to odours during olfactory enrichment sessions. In the initial year of this study, the highest level of interest, evidenced by both the frequency of responses and scent-rolling behaviour, was noted when the wolves encountered odours such as curry and rosemary, along with deer/mouflon and rat faeces. While certain odours, such as llama faeces and deer/mouflon faeces, garnered longer durations of interest in the second year of study, others, like guinea pig faeces and oregano, elicited shorter responses. Female wolves demonstrated a higher level of engagement with scents compared with males, particularly through scent rolling behaviour, which was exclusively observed in females during the second year of this study. Interestingly, certain odours did not trigger scent rolling, suggesting selective preferences. On the other hand, sheep's wool induced the longest duration of scent rolling, and a lack of significant differences in behaviour was observed between morning and afternoon sessions. Despite the existence of multiple hypotheses put forward to explain the causation of scent rolling in wolves, it seems to be elicited by unfamiliar odours.

Dogs understand the role of a human partner in a cooperative task

Humans are exceptionally flexible in cooperation, partly due to our ability to recognize the roles of cooperative partners. While some non-human animals understand the need for a partner in such interactions, it is unclear whether they grasp the consequences of their partner's actions and adjust accordingly. Previous studies utilizing economic games with non-human animals yielded mixed results. We investigated dogs, known for their close cooperation with humans, in a stag hunt game. Dogs could cooperate for better rewards or defect for lower ones, while their human partners would either cooperate, never cooperate, or act randomly. We control for attraction to food, side bias, and local enhancement. Dogs were more likely to coordinate with their partners when it led to better rewards, suggesting that they understood their partner's actions. By highlighting this cognitive skill in dogs, we advance our knowledge of the intricate mechanisms driving cooperative behavior in non-human animals.

Automatic classification of dog barking using deep learning

Barking and other dog vocalizations have acoustic properties related to emotions, physiological reactions, attitudes, or some particular internal states. In the field of intelligent audio analysis, researchers use methods based on signal processing and machine learning to analyze the digitized acoustic signals' properties and obtain relevant information. The present work describes a method to classify the identity, breed, age, sex, and context associated with each bark. This information can support the decisions of people who regularly interact with animals, such as dog trainers, veterinarians, rescuers, police, people with visual impairment. Our approach uses deep neural networks to generate trained models for each classification task. We worked with 19,643 barks recorded from 113 dogs of different breeds, ages and sexes. Our methodology consists of three stages. First, the pre-processing stage prepares the data and transforms it into the appropriate format for each classification model. Second, the characterization stage evaluates different representation models to identify the most suitable for each task. Third, the classification stage trains each classification model and selects the best hyperparameters. After tuning and training each model, we evaluated its performance. We analyzed the most relevant features extracted from the audio and the most appropriate deep neural network architecture for that feature type. Even if the application of our method is not ready for being used in ethological practice, our evaluation showed an outstanding performance of the proposed method, surpassing previous research results on this topic, providing the basis for further technological development.

Intra and interspecific audience effect on domestic dogs' behavioural displays and facial expressions

The aim of the current study was to investigate the influence of both intra- and interspecific audiences on dogs' facial expressions and behaviours. Forty-six dogs were exposed to three test conditions in which a food reward, initially available, was denied when in the presence of either a human (Human condition) or a dog audience (Dog condition), or in the absence of a visible audience (Non-social condition). Salivary cortisol was collected to evaluate the stress/arousal activation in the different conditions. Compared to the Non-social condition, the presence of a conspecific evoked more facial expressions, according to the DogFACS (Facial Action Coding System, an anatomically based tool to analyze facial expressions in domestic dogs), (EAD105-Ears downward), displacement behaviours (AD137-Nose licking, AD37-Lip wiping), tail wagging, whining, and panting (AD126). When facing a conspecific, dogs assumed a more avoidant attitude, keeping a distance and not looking at the stimuli, compared to when in the presence of the human partner. Dogs also exhibited more facial expressions (EAD102-Ears Adductor, EAD104-Ears Rotator), displacement behaviours (AD137-Nose licking, AD37-Lip wiping), panting (AD126) and whining when facing the conspecific than the human partner. Post-test cortisol was not influenced by any condition, and no association between pre-test cortisol and behavioural variables was found, thus strong differences in the levels of stress/arousal were unlikely to be responsible for differences in behavior between conditions. Considering the current results in the context of the available literature, we suggest that the higher displacement behaviors exhibited with the conspecifics were likely due to an increased level of uncertainty regarding the situations.

Raising an Eye at Facial Muscle Morphology in Canids

The evolution of facial muscles in dogs has been linked to human preferential selection of dogs whose faces appear to communicate information and emotion. Dogs who convey, especially with their eyes, a sense of perceived helplessness can elicit a caregiving response from humans. However, the facial muscles used to generate such expressions may not be uniquely present in all dogs, but rather specifically cultivated among various taxa and individuals. In a preliminary, qualitative gross anatomical evaluation of 10 canid specimens of various species, we find that the presence of two facial muscles previously implicated in human-directed canine communication, the levator anguli occuli medialis (LAOM) and the retractor anguli occuli lateralis (RAOL), was not unique to domesticated dogs (Canis familiaris). Our results suggest that these aspects of facial musculature do not necessarily reflect selection via human domestication and breeding. In addition to quantitatively evaluating more and other members of the Canidae family, future directions should include analyses of the impact of superficial facial features on canine communication and interspecies communication between dogs and humans.

Primal awareness, evolutionary restriction, life and the origin of quantum mechanics

We consider resemblances between humans and other species, without adopting categorical positions of either anthropomorphism or anti-anthropomorphism. Our target in doing so is to present a basis for the suggestion of a common ancestor for the similar or differing capabilities exhibited by different species. We propose that individual species exhibit a species-specific selection within what we describe as a universally available 'Basic Capacity to Interact with the Environment' (BCIE). We justify this proposition in terms of the ubiquitous presence at all organizational levels of the Universe of a primal awareness - a precursor of Nature. On disassembling natural organic systems - through neurons, biochemistry … down to quantum mechanics, we note that in its suggested position coupling input-to-output in quantum mechanical operations, primal awareness would be the precursor of quantum mechanics itself. We relate ubiquitous primal awareness to the ideas of David Bohm and Charles Peirce. We point out that genetic Evolution not only provides the basis for the implementation of many capabilities through our 'Basic Capacity to Interact with the Environment', but equally excludes numerous others. This then could explain why different species' Evolution fixes their available/unavailable capabilities. Quantum mechanical superposition/coherence/entanglement are related to our universal primal awareness, in its sense as a ubiquitous precursor. We point out that life is dependent on the classical simulation of quantum mechanics.

Mini-review: Wild laughs: Ontogenesis and phylogenesis of humour

This mini-review discusses the existing evidence on various forms of humour and humour-like behaviour in non-human animals, combining ontogenetic and phylogenetic perspectives. The first section describes humour-like behaviours, from the simplest to the most complex form (from laughing, tickling, joking, and chasing to ToM humour). In the second section, we propose the SPeCies (Social, Physiological, and Cognitive) Perspective, which frames the various types of humour based on Social motivation, Physiological state, and Cognitive skills. Finally, in the third section, we discuss future directions for further development.

The Dog Soundscape: Recurrence, Emotional Impact, Acoustics, and Implications for Dog Observations and Dog-Human Interactions

While numerous dog behavioral studies use environmental sounds, the dog soundscape remains undescribed. We proposed a list of 79 sounds classified into six categories: Dog, Dog accessories, Human, city and vehicles, Garden, countryside and weather, and Household. In a survey, 620 dog owners scored the frequency of their dog's exposure to, and thus, the recurrence of, each of the 79 sounds, from never to daily. The survey results also extended to about 25 sounds the number of acknowledged sounds that are likely to elicit stress or fear, that is, negative emotional sensitivity, in dogs. Sound recurrence and emotional sensitivity were not correlated, showing no beneficial effect of frequent exposure to, and no deleterious effect of scarcity of, sound events. We suggest that for the sake of dog welfare, researchers, veterinarians, trainers, and owners may limit dogs' exposure to the sensitive sounds identified in the study during their dog observations and dog-human interactions. A corpus of 84 sounds was collected. The sounds were spectrally analyzed by determining their F0 and 10 dB bandwidth parameters. At the lowest sound frequencies, where canine hearing is poorest, negative emotional sensitivity was generally low. At the middle and high sound center frequencies/F0s, sensitivity greatly varied from lowest to highest, which is incompatible with both the general assumption and dog auditory detection thresholds. How emotional sensitivity relates to F0 (pitch) and hearing sensitivity remains undetermined. Finally, we suggest that future behavioral audiometric studies of dogs may maximize the spectral spread of each sound while minimizing the spectral overlap between sounds so as to reduce both the testing duration and the risk of inadvertently targeting or, conversely, missing frequency-dependent hearing impairments.

Why do dogs wag their tails?

Tail wagging is a conspicuous behaviour in domestic dogs (Canis familiaris). Despite how much meaning humans attribute to this display, its quantitative description and evolutionary history are rarely studied. We summarize what is known about the mechanism, ontogeny, function and evolution of this behaviour. We suggest two hypotheses to explain its increased occurrence and frequency in dogs compared to other canids. During the domestication process, enhanced rhythmic tail wagging behaviour could have (i) arisen as a by-product of selection for other traits, such as docility and tameness, or (ii) been directly selected by humans, due to our proclivity for rhythmic stimuli. We invite testing of these hypotheses through neurobiological and ethological experiments, which will shed light on one of the most readily observed yet understudied animal behaviours. Targeted tail wagging research can be a window into both canine ethology and the evolutionary history of characteristic human traits, such as our ability to perceive and produce rhythmic behaviours.

Modeling SHANK3-associated autism spectrum disorder in Beagle dogs via CRISPR/Cas9 gene editing

Despite intensive studies in modeling neuropsychiatric disorders especially autism spectrum disorder (ASD) in animals, many challenges remain. Genetic mutant mice have contributed substantially to the current understanding of the molecular and neural circuit mechanisms underlying ASD. However, the translational value of ASD mouse models in preclinical studies is limited to certain aspects of the disease due to the apparent differences in brain and behavior between rodents and humans. Non-human primates have been used to model ASD in recent years. However, a low reproduction rate due to a long reproductive cycle and a single birth per pregnancy, and an extremely high cost prohibit a wide use of them in preclinical studies. Canine model is an appealing alternative because of its complex and effective dog-human social interactions. In contrast to non-human primates, dog has comparable drug metabolism as humans and a high reproduction rate. In this study, we aimed to model ASD in experimental dogs by manipulating the Shank3 gene as SHANK3 mutations are one of most replicated genetic defects identified from ASD patients. Using CRISPR/Cas9 gene editing, we successfully generated and characterized multiple lines of Beagle Shank3 (bShank3) mutants that have been propagated for a few generations. We developed and validated a battery of behavioral assays that can be used in controlled experimental setting for mutant dogs. bShank3 mutants exhibited distinct and robust social behavior deficits including social withdrawal and reduced social interactions with humans, and heightened anxiety in different experimental settings (n = 27 for wild-type controls and n = 44 for mutants). We demonstrate the feasibility of producing a large number of mutant animals in a reasonable time frame. The robust and unique behavioral findings support the validity and value of a canine model to investigate the pathophysiology and develop treatments for ASD and potentially other psychiatric disorders.

Scientific and technical assistance on welfare aspects related to housing and health of cats and dogs in commercial breeding establishments

This Scientific Report addresses a mandate from the European Commission according to Article 31 of Regulation (EC) No 178/2002 on the welfare of cats and dogs in commercial breeding establishments kept for sport, hunting and companion purposes. The aim was to scrutinise recent recommendations made by the EU Platform on Animal Welfare Voluntary Initiative on measures to assist the preparation of policy options for the legal framework of commercial breeding of cats and dogs. Specifically, the main question addressed was if there is scientific evidence to support the measures for protection of cats and dogs in commercial breeding related to housing, health considerations and painful procedures. Three judgements were carried out based on scientific literature reviews and, where possible a review of national regulations. The first judgement addressed housing and included: type of accommodation, outdoor access, exercise, social behaviour, housing temperature and light requirements. The second judgement addressed health and included: age at first and last breeding, and breeding frequency. Judgement 3 addressed painful procedures (mutilations or convenience surgeries) and included: ear cropping, tail docking and vocal cord resections in dogs and declawing in cats. For each of these judgements, considerations were provided indicating where scientific literature is available to support recommendations on providing or avoiding specific housing, health or painful surgical interventions. Areas where evidence is lacking are indicated.

Grey wolves (Canis lupus) discriminate between familiar and unfamiliar human voices

The ability to discriminate between different individuals based on identity cues, which is important to support the social behaviour of many animal species, has mostly been investigated in conspecific contexts. A rare example of individual heterospecific discrimination is found in domestic dogs, who are capable of recognising their owners' voices. Here, we test whether grey wolves, the nearest wild relative of dogs, also have the ability to distinguish familiar human voices, which would indicate that dogs' ability is not a consequence of domestication. Using the habituation-dishabituation paradigm, we presented captive wolves with playback recordings of their keepers' and strangers' voices producing either familiar or unfamiliar phrases. The duration of their response was significantly longer when presented with keepers' voices than with strangers' voices, demonstrating that wolves discriminated between familiar and unfamiliar speakers. This suggests that dogs' ability to discriminate between human voices was probably present in their common ancestor and may support the idea that this is a general ability of vertebrates to recognise heterospecific individuals. Our study also provides further evidence for familiar voice discrimination in a wild animal in captivity, indicating that this ability may be widespread across vertebrate species.

Relationship between asymmetric nostril use and human emotional odours in cats

Cat social behaviour and cognition has received a growing interest during the last decades. Recent studies reported that cats efficiently engage in interspecific communication with humans and suggest that cats are sensitive to human emotional visual and auditory cues. To date, there is no evidence on the social and informative role of human emotional odours, which may affect human-cat communication. In this study, we presented cats with human odours collected in different emotional contexts (fear, happiness, physical stress and neutral) and evaluated the animals' behavioural responses. We found that "fear" odours elicited higher stress levels than "physical stress" and "neutral", suggesting that cats perceived the valence of the information conveyed by "fear" olfactory signals and regulate their behaviour accordingly. Moreover, the prevalent use of the right nostril (right hemisphere activation) with the increase of stress levels, particularly in response to "fear" odours, provides first evidence of lateralized emotional functions of olfactory pathways in cats.

Functionally analogous body- and animacy-responsive areas are present in the dog (Canis familiaris) and human occipito-temporal lobe

Comparing the neural correlates of socio-cognitive skills across species provides insights into the evolution of the social brain and has revealed face- and body-sensitive regions in the primate temporal lobe. Although from a different lineage, dogs share convergent visuo-cognitive skills with humans and a temporal lobe which evolved independently in carnivorans. We investigated the neural correlates of face and body perception in dogs (N = 15) and humans (N = 40) using functional MRI. Combining univariate and multivariate analysis approaches, we found functionally analogous occipito-temporal regions involved in the perception of animate entities and bodies in both species and face-sensitive regions in humans. Though unpredicted, we also observed neural representations of faces compared to inanimate objects, and dog compared to human bodies in dog olfactory regions. These findings shed light on the evolutionary foundations of human and dog social cognition and the predominant role of the temporal lobe.

Visual perception of emotion cues in dogs: a critical review of methodologies

Comparative studies of human-dog cognition have grown exponentially since the 2000's, but the focus on how dogs look at us (as well as other dogs) as social partners is a more recent phenomenon despite its importance to human-dog interactions. Here, we briefly summarise the current state of research in visual perception of emotion cues in dogs and why this area is important; we then critically review its most commonly used methods, by discussing conceptual and methodological challenges and associated limitations in depth; finally, we suggest some possible solutions and recommend best practice for future research. Typically, most studies in this field have concentrated on facial emotional cues, with full body information rarely considered. There are many challenges in the way studies are conceptually designed (e.g., use of non-naturalistic stimuli) and the way researchers incorporate biases (e.g., anthropomorphism) into experimental designs, which may lead to problematic conclusions. However, technological and scientific advances offer the opportunity to gather much more valid, objective, and systematic data in this rapidly expanding field of study. Solving conceptual and methodological challenges in the field of emotion perception research in dogs will not only be beneficial in improving research in dog-human interactions, but also within the comparative psychology area, in which dogs are an important model species to study evolutionary processes.

How Do Dogs Behave When Presented with Situations of Different Emotional Valences?

Dogs are good models for studying behaviour and cognition as they have complex social capabilities. In the current study, we observed how human emotional valences (positive, neutral and negative) affected aspects of dogs' behaviour. We expected that dogs would exhibit more approaching behaviours in the positive condition and more signs of avoidance in the negative one. We analysed videos of 70 adult pet dogs of various breeds taken from an experiment in which one of two actors expressed an emotion and dogs could freely explore the environment for 30 s. Our results show that dogs exhibit differential behaviour when presented with different emotional valences. Two behaviours arose that might be linked to a reciprocal positive emotional state in dogs: tail raised between 90° and 180° and physical contact during sniffing. These behaviours are associated with an active search for information. In the positive conditions, dogs were more willing to explore the social environment and gather information from the actors.

Dogs with cropped ears in the UK: A population-based study using electronic health records

BACKGROUND

Ear cropping for cosmetic purposes was made illegal in the UK in 2006. Despite this, a lack of import regulations and celebrity and media influences mean cropped dogs are increasingly reported.

METHODS

The demographics, temporal trends and patient-level associated factors for dogs with cropped ears were evaluated in a large sentinel population of dogs visiting UK veterinary practices.

RESULTS

A total of 132 dogs with cropped ears were identified, with rates peaking in 2021. In 84 cases (63.6%), there was evidence of importation, most commonly from countries where cropping is also illegal, including Romania, Hungary, Bulgaria, Serbia, Spain, Poland and Ireland. American Bulldogs, Dobermanns, Italian Mastiffs (Cane Corso), Bulldogs and Mastiffs were all significantly overrepresented. Affected dogs were more likely to be unneutered (odds ratio 11.04, 95% confidence interval 5.84-20.90).

LIMITATIONS

The study likely underestimates true levels of ear cropping. Identified cases are from a sentinel network of veterinary practices, and as such may not be representative of the wider UK population.

CONCLUSION

These data suggest a need to educate owners and veterinary surgeons about the welfare and legal implications of ear cropping. The data presented can inform future targeted policies in veterinary practices and at a governmental level.

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.

Appeasement function of displacement behaviours? Dogs' behavioural displays exhibited towards threatening and neutral humans

Appeasement signals are behavioural patterns displaying an animal's non-aggressive attitude and are hypothesized to reduce the aggressive behaviours in the receiver. In domestic dogs, specific displacement behaviours (i.e., behavioural patterns exhibited without an apparent function related to the ongoing situation), have been suggested to function as appeasement signals. To test this possibility, we assessed whether the occurrence of these behaviours was dependent on a social conflict context, predicting that, if displacement behaviours also function as appeasement signals, they should be more prevalent in a conflict vs. non-conflict context. Fifty-three dogs were exposed to two unfamiliar humans approaching them in either a mildly threatening or neutral way. We categorized the attitude of the dogs towards the strangers as "reactive", i.e., barking and lunging towards the stimulus, and "non-reactive", i.e., remaining passive in front of the stimuli. We coded dogs' displacement activities and modelled their duration or frequency as a function of the interaction between the test condition and the attitude of the dog. Displacement behaviours of "blinking", "nose licking" and "lip wiping" were associated with a "non-reactive" attitude, independently from the test condition, confirming an association with a non-aggressive intention. "Head turning" was associated with a "non-reactive" attitude in the threatening condition. In conclusion, dogs with a non-aggressive attitude exhibited more putative appeasement signals; however, these were not strictly associated with a conflict-ridden situation, calling for further investigation of their function.

Facial asymmetry in dogs with fear and aggressive behaviors towards humans

There is now scientific evidence that, in dogs, distinctive facial actions are produced in response to different emotionally-arousing stimuli suggesting a relationship between lateralized facial expressions and emotional states. Although in humans, relationships between facial asymmetry and both emotional and physiological distress have been reported, there are currently no data on the laterality of dogs' facial expressions in response to social stimuli with respect to canine behavioral disorders. The aim of the present work was to investigate the facial asymmetries of dogs with fear and aggressive behavior towards humans during two different emotional situations: (1) while the dogs were alone in the presence of their owners and (2) during the approach of an unfamiliar human being. Overall, our results demonstrated high levels of asymmetries in facial expressions of dogs displaying fear and aggressive behaviors towards humans indicating that measuring facial asymmetries in dogs could prove to be a useful non-invasive tool for investigating physiology-based behavioral disorders.

Comparison of behavioural tendencies between "dangerous dogs" and other domestic dog breeds - Evolutionary context and practical implications

Aggressive behaviour by dogs is a considerable social problem, but the ability to predict which individuals may have increased aggressive tendencies is very limited, restricting the development of efficient preventive measures. There is a common perception that certain breeds are more likely to exhibit aggressive behaviour, which has contributed to the introduction of breed-specific legislation. The rationale for such legislation explicitly assumes high heritability of this trait while also implying relatively little variation within breeds; these assumptions are largely untested. We compared behavioural tendencies between 8 breeds that are subject to legislation in at least one country and 17 breeds that are not subject to legislation using two validated psychometric tools: the Dog Impulsivity Assessment Scale (DIAS), which scores elements of impulsivity, including a tendency for aggressive behaviour, and Positive and Negative Activation Scale (PANAS), which scores sensitivity to positive and negative stimuli (which may trigger aggressive responses). We found that the two groups of breeds do not differ significantly in the specific DIAS factor relating to aggressive behaviour, "Aggression Threshold and Response to Novelty", or any other DIAS and PANAS factors. We found large variations in all behavioural tendencies measured by both psychometric scales within both groups and within each breed studied. Taken together, our findings indicate that breed alone is not a reliable predictor of individual behavioural tendencies, including those related to aggression, and therefore breed-specific legislation is unlikely to be an effective instrument for reducing risk.

Pet ownership, feelings of loneliness, and mood in people affected by the first COVID-19 lockdown

The outbreak of the COVID-19 pandemic has caused dramatic changes to our lifestyle, particularly affecting our ability to interact "in person" with our social network. These changes have had a detrimental effect on the mental welfare of the global population. The international questionnaire "Pets in Lockdown" was designed to investigate whether feelings of loneliness were affecting the mood of people during the COVID-19 lockdown and whether pet ownership may have had a positive influence on both loneliness and general mood. As expected, higher loneliness scores were associated with higher negative and lower positive affective states. In addition, lower loneliness scores were associated with pet ownership and living with other people, but not with more frequent interactions with people from outside the household, suggesting that physical and close contact has an important role in decreasing feelings of loneliness. Besides the effects on the loneliness score, pet ownership was not associated with positive or negative affective states. The strength of the attachment to animals, measured as the amount of comfort that people obtain from their pets, was stronger in people with potentially limited access to affiliative physical human contact and was associated with both higher positive and negative affective states. Additionally, people obtained significantly more comfort from dogs and horses compared with other pet species. The results suggest that during the confinement period, pets may have benefited people with smaller social networks by alleviating loneliness and offering comfort and embodied close contact.

Effects of a Novel Gel Formulation of Dog Appeasing Pheromone (DAP) on Behavioral and Physiological Stress Responses in Dogs Undergoing Clinical Examination

Simple Summary

Safeguarding the health of dogs presupposes undergoing regular veterinary visits (VVs). However, the VV can be emotionally challenging, thus impairing the welfare of the patient, also reducing dog and owner compliance. The fear and anxiety experienced by the dogs evokes behavioral and physiological stress responses for adaptive purposes. It is therefore desirable to lower the stress from the visit. With this intent, we tested a gel formulation of a synthetic analogue of the appeasing pheromone secreted by bitches, the dog appeasing pheromone (DAP), as a situational support to improve the perception of the stay in the waiting room and the physical examination. In the waiting room, the dogs exposed to DAP exhibited changes in their behavior, namely significant decrease in lip licking, increase in panting, and nearly significant reduction of low body postures. On the examination table, neither behavioral nor physiological differences were found. DAP did not alter markedly the stress behavior and physiology of dogs during a VV, maybe due to a stress level exceeding the potential efficacy of the product. However, the change of a few stress-associated behaviors suggests that DAP could contribute to improving the welfare of dogs staying in the waiting room before the physical examination.

Abstract

The veterinary visit is necessary for safeguarding the health of dogs, but it can be stressful and threaten both the welfare of the patient and the accuracy of the examination. This randomized, triple-blind, placebo-controlled, crossover study aims at evaluating how dog appeasing pheromone (DAP) in a novel gel formulation influences the behavioral and physiological stress responses of 28 dogs undergoing a standardized clinical examination, while staying in the waiting room (WR) and visited in the examination room (ER). Behavioral responses were studied through behavioral categories and subjective scales (WR and ER). Autonomic response considered heart rate (WR and ER), blood pressure (WR and ER), respiratory rate (ER), and rectal temperature (ER). Neuroendocrine response considered salivary cortisol (WR and ER). In the waiting room, the use of DAP was associated with a significant reduction of lip licking (p = 0.0189), an increase in panting (p = 0.0276), and a reduction close to significance (p = 0.0584) of low body postures. No significant differences were observed within the physiological responses. In the examination room, neither behavioral nor physiological differences were found.

Audience effect on domestic dogs' behavioural displays and facial expressions

In the present study we investigated the influence of positive and negative arousal situations and the presence of an audience on dogs’ behavioural displays and facial expressions. We exposed dogs to positive anticipation, non-social frustration and social frustration evoking test sessions and measured pre and post-test salivary cortisol concentrations. Cortisol concentration did not increase during the tests and there was no difference in pre or post-test concentrations in the different test conditions, excluding a different level of arousal. Displacement behaviours of “looking away” and “sniffing the environment” occurred more in the frustration-evoking situations compared to the positive anticipation and were correlated with cortisol concentrations. “Ears forward” occurred more in the positive anticipation condition compared to the frustration-evoking conditions, was positively influenced by the presence of an audience, and negatively correlated to the pre-test cortisol concentrations, suggesting it may be a good indicator of dogs’ level of attention. “Ears flattener”, “blink”, “nose lick”, “tail wagging” and “whining” were associated with the presence of an audience but were not correlated to cortisol concentrations, suggesting a communicative component of these visual displays. These findings are a first step to systematically test which subtle cues could be considered communicative signals in domestic dogs.

Dog-Owner Relationship, Owner Interpretations and Dog Personality Are Connected with the Emotional Reactivity of Dogs

We evaluated the effect of the dog-owner relationship on dogs' emotional reactivity, quantified with heart rate variability (HRV), behavioral changes, physical activity and dog owner interpretations. Twenty nine adult dogs encountered five different emotional situations (i.e., stroking, a feeding toy, separation from the owner, reunion with the owner, a sudden appearance of a novel object). The results showed that both negative and positive situations provoked signs of heightened arousal in dogs. During negative situations, owners' ratings about the heightened emotional arousal correlated with lower HRV, higher physical activity and more behaviors that typically index arousal and fear. The three factors of The Monash Dog-Owner Relationship Scale (MDORS) were reflected in the dogs' heart rate variability and behaviors: the Emotional Closeness factor was related to increased HRV (p = 0.009), suggesting this aspect is associated with the secure base effect, and the Shared Activities factor showed a trend toward lower HRV (p = 0.067) along with more owner-directed behaviors reflecting attachment related arousal. In contrast, the Perceived Costs factor was related to higher HRV (p = 0.009) along with less fear and less owner-directed behaviors, which may reflect the dog's more independent personality. In conclusion, dogs' emotional reactivity and the dog-owner relationship modulate each other, depending on the aspect of the relationship and dogs' individual responsivity.

Tail posture and motion in relation to natural behaviour in juvenile and adult pigs

The tail of pigs has been suggested as a welfare indicator as it can provide insight into a pig's behavioural and emotional states. Tail posture and motion have so far mainly been studied in the context of tail biting behaviour. The aim of this study was to investigate the relationship between pigs' natural behaviour and their tail posture and tail motion. This was studied in a free-range farm in which tail biting is absent. In total 214 pigs of different age categories were observed individually (sows, gilts, boars, and 6-month old pigs) or by group (6-month and 1-year old pigs) for their tail posture, tail motion and behaviour, using live observations and videos obtained by drone. Results showed that a fully curled tail occurred most during locomotion (P < 0.001); and an actively hanging tail occurred more during foraging (P < 0.001), excavation (P = 0.006), feeding (P = 0.017), receipt of agonistic behaviour (P = 0.036), and non-agonistic social interactions (P = 0.046). A fully curled tail (P < 0.001) and a half curled tail (P < 0.005) occurred least in the group of sows. Tail motion was infrequent (6.7% of observations), and involved mainly loosely wagging, which occurred more during locomotion (P = 0.006) and non-agonistic social interactions (P = 0.006). A higher temperature-humidity index increased the probability of half curled tails (P < 0.001) and loose wagging (P < 0.001), while reducing the probability of active (P < 0.001) and passive hanging tails (P = 0.013). These results provide insight into tail posture and tail motion in pigs under semi-natural conditions, showing especially that hanging tails are not primarily associated with tail biting, and that the use of tail postures for welfare assessment should be in consideration with the context in which the animals are kept.

Motivations of Human Helping Behavior towards Dogs

Human–dog interactions have a positive effect on human sociality and health. The relationship with dogs helps humans to cope with stress during an emotionally challenging period, such as the COVID-19 pandemic. During this period, a growing global interest in pets has been registered, including the volunteering for shelter/stray dog protection. However, a considerable increase of human dysfunctional interventions toward dogs has been observed in Southern Italy. In this study, we investigated the psychological characteristics of humans volunteering at animal shelter or engaged in stray dog protection. The effect of psychological training and education about dog ethological needs on volunteers’ helping behavior was also analyzed. We report that the intervention can improve volunteers’ physiological features and, consequently, may enhance human management and dog welfare.

Pet-directed speech improves horses' attention toward humans

In a recent experiment, we showed that horses are sensitive to pet-directed speech (PDS), a kind of speech used to talk to companion animals that is characterized by high pitch and wide pitch variations. When talked to in PDS rather than adult-directed speech (ADS), horses reacted more favorably during grooming and in a pointing task. However, the mechanism behind their response remains unclear: does PDS draw horses’ attention and arouse them, or does it make their emotional state more positive? In this study, we used an innovative paradigm in which female horses watched videos of humans speaking in PDS or ADS to better understand this phenomenon. Horses reacted differently to the videos of PDS and ADS: they were significantly more attentive and their heart rates increased significantly more during PDS than during ADS. We found no difference in the expressions of negative or positive emotional states during PDS and ADS videos. Thus, we confirm that horses’ perception of humans can be studied by means of video projections, and we conclude that PDS attracts attention and has an arousing effect in horses, with consequences on the use of PDS in daily interactions with them.

Handlers' Representations on Therapy Dogs' Welfare

While research on the benefits of animal-assisted interventions is beginning to build a significant body of work, studies on the well-being of therapy dogs are still in their infancy. Since handlers are the people responsible for their therapy dog's welfare, we interviewed 111 French handlers through an online questionnaire. Our results underlined that (i) therapy dogs' welfare is multidimensional when physical and psychological welfare, a balance between work and dog life and the settings and interactions of sessions are all taken into consideration. (ii) The response of our handlers emphasized that considering therapy dog welfare is important for the quality and safety of AAI. (iii) Three categories of risks factors were highlighted: the spatio-temporal framework (planning and environment), the interactions with beneficiaries and the handler themselves. It is particularly important that handlers talk about the negative impact of interactions with beneficiaries since they are at the heart of AAI, however there are few studies focusing on interactions as a stressor for dogs in this practice. Moreover, since there is a potential for positive bias in the handlers' representations, it is important that they be trained to identify and manage the stress in their dogs. Future research is particularly needed on the impact of interactions during sessions on therapy dog welfare.

Review on Selected Aggression Causes and the Role of Neurocognitive Science in the Diagnosis

Simple Summary

Aggression in dogs is often a reason for abandonment and/or euthanasia. Recently, knowledge about aggression has been subjected to more detailed analysis. In recent years, it has been studied in terms of factors affecting it, such as diet (especially nutritional supplements) and physiology (endocrine system). In addition, recently, new methods of brain research, such as neurocognitive research, have appeared, which enable a significant increase in knowledge about dog behavior, including aggression.

Abstract

Aggression as a behavior is not always desirable, often ends in abandonment and/or euthanasia. However, it is possible to prevent the occurrence of unwanted aggression in domestic dogs. Aggression is not a fully understood phenomenon. In recent years, many studies have focused on the influence of diet and physiology (including the endocrine system) on the emergence of behavioral disorders. In particular, the emphasis was put on nutritional additives such as fatty acids, amino acids, and probiotics. In addition, the possibility of using neurocognition in the observation of abnormal behavior in dogs has also been discussed, which may allow for a more detailed determination of the basis of aggressive behavior in dogs. In this review, the concepts related to aggression and its potential causes have been gathered. In addition, the possible influence of diet and hormones on aggression in dogs has been discussed, as well as the application of neurocognition in the possibility of its diagnosis.

Impact of Classical Counterconditioning (Quiet Kennel Exercise) on Barking in Kenneled Dogs—A Pilot Study

Simple Summary

Barking is a major source of noise pollution in dog kennels and negatively impacts the welfare of anyone within earshot, especially the dogs in the kennels themselves. It is crucial to have solutions to help reduce barking quickly and humanely that are easy to understand and put into place that also do not require a lot of resources such as time, expertise, or money. This study looked at the use of an exercise (Quiet Kennel Exercise—QKE) that uses classical counterconditioning (Pavlov) to help change the way the dogs feel when a person enters the kennel area from unpleasant to pleasant. This should help to reduce barking, especially that which is caused by negative emotions such as fear and frustration. After the initial baseline period of 5 days, people passing through the kennel tossed treats to the dogs no matter what the dogs did for 10 days. Data was collected three times a day for the entire study period. Sound level readings (decibels), number of dogs present, and number of dogs barking were recorded. Results showed improvement in the loudest volume recorded after the exercise was in place, fewer dogs barking over time, and each dog barking less each time. The most improvement was noticed in the afternoon.

Abstract

Excessive barking is a major source of noise pollution in dog kennels and negatively impacts welfare. Because resources are often limited, minimizing barking in the simplest and most easily implementable way is imperative. This pilot study implemented a Quiet Kennel Exercise (QKE) that utilized classical counterconditioning to change the dogs’ negative emotional state (which can lead to barking) to a more positive emotional state. Therefore, barking motivation is reduced, so barking should decrease. This study aims to show proof of concept that decreasing barking through classical counterconditioning is effective. It was conducted in one ward of day-time boarding kennels at North Carolina State University College of Veterinary Medicine. Data was collected three times per day and included decibel readings, number of dogs present, and number of dogs barking during a 5-day initial baseline and 10-day intervention period. During baseline, people passing through the ward acted as they normally would. During intervention, passersby were asked to simply toss each dog a treat regardless of the dogs’ behaviors in the kennel. Descriptive results show improvement in maximum level of barking after QKE, fewer dogs barking over time, dogs barking less each time, and the most improvement noted in the afternoon.

How Parents Perceive the Potential Risk of a Child-Dog Interaction

Dog attacks on children are a widespread problem, which can occur when parents fail to realise a potentially dangerous interaction between a dog and a child. The aim of the study was to evaluate the ability of parents to identify dangerous situations from several everyday child–dog interactions and to determine whether the participants connected these situations to a particular breed of dog. Five sets of photographs depicting potentially dangerous interactions from everyday situations between children and three dogs (one of each breed) were presented via an online survey to parents of children no more than 6 years old. Data from 207 respondents were analysed using proc GLIMMIX in SAS program, version 9.3. The probability of risk assessment varied according to dog breed (p < 0.001) as well as to the depicted situation (p < 0.001). Results indicated that Labrador Retriever was considered the least likely of the three dogs to be involved in a dangerous dog-child interaction (with 49% predicting a dangerous interaction), followed by Parson Russell Terrier (63.2%) and American Pit Bull Terrier (65%). Participants considered one particular dog-child interaction named ‘touching a bowl’ a dangerous interaction at a high rate (77.9%) when compared with the other presented situations, which were assessed as dangerous at rates of 48.4% to 56.5%. The breed of dog seems to be an influential factor when assessing a potentially dangerous outcome from a dog-child interaction. Contrary to our hypothesis, interactions involving the small dog (Russell Terrier) were rated more critically, similarly to those of the Pit Bull Terrier. These results suggest that even popular family dog breeds, such as Labrador Retrievers, should be treated with more caution.

OUP accepted manuscript

Mesenchymal stem cell-based therapy has emerged as a great potential approach to treat individuals with autism spectrum disorders (ASD), a group of developmental disabilities characterized by impairments in social interaction and communication. Stem cells from human exfoliated deciduous teeth (SHED), holding earlier developing characteristics, have immune-modulatory and anti-inflammatory properties. To investigate whether SHED transplantation can rescue autistic-like symptoms in SHANK3 mutant beagle dogs, 12 SHANK3 mutant beagle dogs were randomly assigned into 2 groups according to their behavior evaluated by social interaction tests. Six mutant dogs received 6 intravenous infusions of SHED and were followed up for 3 months by testing social interaction and inflammatory cytokine levels. We found that infusion of SHED significantly improved impaired social novel preference of SHANK3 mutant beagle dogs at 1- and 3-month follow-ups. Social intimacies (following, sniffing, and licking) between mutant beagle dogs and human experimenters were partly improved. Stressed tail posture, indicating social stress, was also significantly alleviated. In addition, we showed that the levels of serum interferon-γ and interleukin-10 were notably increased and decreased, respectively, in SHANK3 mutant beagle dogs. Infusion of SHED was able to rescue altered interferon-γ and interleukin-10 levels. We failed to observe any serious adverse events after infusion of SHED. In summary, SHED transplantation may be a safe and effective therapy for ASD. The correction in the levels of serum interferon-γ and interleukin-10 may serve as an index to predict autistic severity and therapeutic outcomes.

Canine and Feline Parasitology: Analogies, Differences, and Relevance for Human Health

Cats and dogs are treated as family members by most pet owners. Therefore, a high quality of veterinary care and preventive medicine is imperative for animal health and welfare and for the protection of humans from zoonotic pathogens. There is a general perception of cats being treated as "small dogs," especially in the field of clinical parasitology. As a result, several important differences between the two animal species are not taken into proper consideration and are often overlooked. Dogs and cats are profoundly different under evolutionary, biological, ethological, behavioral, and immunological standpoints. These differences impact clinical features, diagnosis, and control of canine and feline parasites and transmission risk for humans. This review outlines the most common parasitoses and vector-borne diseases of dogs and cats, with a focus on major convergences and divergences, and discusses parasites that have (i) evolved based on different preys for dogs and cats, (ii) adapted due to different immunological or behavioral animal profiles, and (iii) developed more similarities than differences in canine and feline infections and associated diseases. Differences, similarities, and peculiarities of canine and feline parasitology are herein reviewed in three macrosections: (i) carnivorism, vegetarianism, anatomy, genetics, and parasites, (ii) evolutionary adaptation of nematodes, including veterinary reconsideration and zoonotic importance, and (iii) behavior and immune system driving ectoparasites and transmitted diseases. Emphasis is given to provide further steps toward a more accurate evaluation of canine and feline parasitology in a changing world in terms of public health relevance and One Health approach.

Current Advances in Assessment of Dog's Emotions, Facial Expressions, and Their Use for Clinical Recognition of Pain

Animals' facial expressions are involuntary responses that serve to communicate the emotions that individuals feel. Due to their close co-existence with humans, broad attention has been given to identifying these expressions in certain species, especially dogs. This review aims to analyze and discuss the advances in identifying the facial expressions of domestic dogs and their clinical utility in recognizing pain as a method to improve daily practice and, in an accessible and effective way, assess the health outcome of dogs. This study focuses on aspects related to the anatomy and physiology of facial expressions in dogs, their emotions, and evaluations of their eyebrows, eyes, lips, and ear positions as changes that reflect pain or nociception. In this regard, research has found that dogs have anatomical configurations that allow them to generate changes in their expressions that similar canids-wolves, for example-cannot produce. Additionally, dogs can perceive emotions similar to those of their human tutors due to close human-animal interaction. This phenomenon-called "emotional contagion"-is triggered precisely by the dog's capacity to identify their owners' gestures and then react by emitting responses with either similar or opposed expressions that correspond to positive or negative stimuli, respectively. In conclusion, facial expressions are essential to maintaining social interaction between dogs and other species, as in their bond with humans. Moreover, this provides valuable information on emotions and the perception of pain, so in dogs, they can serve as valuable elements for recognizing and evaluating pain in clinical settings.

Emotions and Dog Bites: Could Predatory Attacks Be Triggered by Emotional States?

Simple Summary

Dog bites are a worldwide problem that have severe consequences for both the animal and the victim involved in the incident. Epidemiological studies have analyzed the victim features, the characteristics of biting dogs and the context in which attacks occur. Little is known regarding the role of emotions in predatory attacks toward humans and conspecifics in dogs. This paper aims at proposing the potential involvement of emotions for the expression of predatory motor patterns. It is suggested that the reporting of dog biting episodes needs to consider this crucial factor, which is fundamental for providing a realistic and reliable picture of the dog bite phenomenon.

Abstract

Dog biting events pose severe public health and animal welfare concerns. They result in several consequences for both humans (including physical and psychological trauma) and the dog involved in the biting episode (abandonment, relocation to shelter and euthanasia). Although numerous epidemiological studies have analyzed the different factors influencing the occurrence of such events, to date the role of emotions in the expression of predatory attacks toward humans has been scarcely investigated. This paper focuses on the influence of emotional states on triggering predatory attacks in dogs, particularly in some breeds whose aggression causes severe consequences to human victims. We suggest that a comprehensive analysis of the dog bite phenomenon should consider the emotional state of biting dogs in order to collect reliable and realistic data about bite episodes.

Hunting dogs bark differently when they encounter different animal species

Previous studies have shown that vocalizations of dogs can provide information to human companions. While acoustic signals of dogs have been intensively studied during the last decade, barking during hunting activities remains unstudied. The experiences of hunters indicate that owners can recognize what animal species has been found based on the bark of their dog. Such a phenomenon has never been tested before. We tested such an ability by comparing barks that were produced when dogs encountered four different animal species: wild boar, red fox, rabbit and fowl. Classification results of a discrimination analysis showed, that based on barks of dachshunds and terriers, it is possible to categorize towards which animal species barks were produced. The most distinctive barks were produced during encounters with the most dangerous of these animals, the wild boar. On the contrary, barks evoked by red fox encounters were classified similarly as those towards other smaller and non-dangerous animals like rabbits and fowl. Although the red fox represents a potentially dangerous species, the barking provoked was not classified with a much higher result than barking at animals that pose no threat. This might indicate that the key parameter could be the body size of the animal the dog meets. We further tested whether the degree of threat from the species of animal the dog encounters is reflected in the structure of the acoustic parameters based on the valence-arousal model. We found that barks produced in contact with a wild boar showed significantly lower frequency parameters and longest duration compared to other barks. According to these results, it seems that the variability of barking depending on the species of animal a dog encounters is an expression of the dogʼs inner state rather than functionally reference information.

Cognition and the human-animal relationship: a review of the sociocognitive skills of domestic mammals toward humans

In the past 20 years, research focusing on interspecific sociocognitive abilities of animals toward humans has been growing, allowing a better understanding of the interactions between humans and animals. This review focuses on five sociocognitive abilities of domestic mammals in relation to humans as follows: discriminating and recognizing individual humans; perceiving human emotions; interpreting our attentional states and goals; using referential communication (perceiving human signals or sending signals to humans); and engaging in social learning with humans (e.g., local enhancement, demonstration and social referencing). We focused on different species of domestic mammals for which literature on the subject is available, namely, cats, cattle, dogs, ferrets, goats, horses, pigs, and sheep. The results show that some species have remarkable abilities to recognize us or to detect and interpret the emotions or signals sent by humans. For example, sheep and horses can recognize the face of their keeper in photographs, dogs can react to our smells of fear, and pigs can follow our pointing gestures. Nevertheless, the studies are unequally distributed across species: there are many studies in animals that live closely with humans, such as dogs, but little is known about livestock animals, such as cattle and pigs. However, on the basis of existing data, no obvious links have emerged between the cognitive abilities of animals toward humans and their ecological characteristics or the history and reasons for their domestication. This review encourages continuing and expanding this type of research to more abilities and species.

Evaluating the accuracy of facial expressions as emotion indicators across contexts in dogs

Facial expressions potentially serve as indicators of animal emotions if they are consistently present across situations that (likely) elicit the same emotional state. In a previous study, we used the Dog Facial Action Coding System (DogFACS) to identify facial expressions in dogs associated with conditions presumably eliciting positive anticipation (expectation of a food reward) and frustration (prevention of access to the food). Our first aim here was to identify facial expressions of positive anticipation and frustration in dogs that are context-independent (and thus have potential as emotion indicators) and to distinguish them from expressions that are reward-specific (and thus might relate to a motivational state associated with the expected reward). Therefore, we tested a new sample of 28 dogs with a similar set-up designed to induce positive anticipation (positive condition) and frustration (negative condition) in two reward contexts: food and toys. The previous results were replicated: Ears adductor was associated with the positive condition and Ears flattener, Blink, Lips part, Jaw drop, and Nose lick with the negative condition. Four additional facial actions were also more common in the negative condition. All actions except the Upper lip raiser were independent of reward type. Our second aim was to assess basic measures of diagnostic accuracy for the potential emotion indicators. Ears flattener and Ears downward had relatively high sensitivity but low specificity, whereas the opposite was the case for the other negative correlates. Ears adductor had excellent specificity but low sensitivity. If the identified facial expressions were to be used individually as diagnostic indicators, none would allow consistent correct classifications of the associated emotion. Diagnostic accuracy measures are an essential feature for validity assessments of potential indicators of animal emotion.

The Untrained Response of Pet Dogs to Human Epileptic Seizures

Epilepsy is a debilitating and potentially life-threatening neurological condition which affects approximately 65 million people worldwide. There is currently no reliable and simple early warning seizure-onset device available, which means many people with unstable epilepsy live in fear of injury or sudden death and the negative impact of social stigmatization. If anecdotal claims that untrained dogs anticipate seizures are found to be true, they could offer a simple and readily available early warning system. We hypothesized that, given the extraordinary olfactory ability of dogs, a volatile organic compound exhaled by the dog's epileptic owner may constitute an early warning trigger mechanism to which make dogs react by owner-directed affiliative responses in the pre-seizure period. Using 19 pet dogs with no experience of epilepsy, we exposed them to odours that were deemed to be characteristic of three seizure phases, by using sweat harvested from people with epilepsy. The odours were delivered to a point immediately under a non-epileptic and seated pet dog owner's thighs. By altering the alternating odours emerging from sweat samples, captured before seizure, during a seizure and after a seizure, and two nonseizure controls, we were able to record the response of the 19 pet dogs. Our findings suggest that seizures are associated with an odour and that dogs detect this odour and demonstrate a marked increase in affiliative behaviour directed at their owners. A characteristic response of all 19 dogs to seizure odour presentation was an intense stare which was statistically significant, (p < 0.0029), across the pre-seizure, seizure and post-seizure phases when compared to control odours of nonseizure origin.

Still-face Effect in Dogs (Canis familiaris). A Pilot Study

The Still-face Paradigm has been widely used for the assessment of emotion regulation in infants, as well as for the study of the mother-child relationship. Given the close bond that dogs have with humans, the purpose of this research was to evaluate, through an exploratory descriptive study, the presence of the Still-face effect in dogs. To this end, a group of Beagle dogs were exposed to three one-minute phases in which first, an unknown experimenter interacted actively and positively with each dog (Interaction). Then, suddenly, she interrupted the interaction and remained passive, with a non-expressive face and without speaking or petting the dog (Still-face). Finally, the experimenter reestablished the interaction (Reunion). Our results showed a decrease in affiliative behaviors in dogs during the Still-face phase according to changes in the human's behavior, a pattern similar to the one previously found in infants. Contrary to expectations, no stress-related behaviors were shown during that phase. A carry-over effect was also observed in the Reunion phase. This study provides information about the human-dog interaction and the effects of its disruption on dogs' behaviors.

Artificially elevated oxytocin concentrations in pet dogs are associated with higher proximity-maintenance and gazing towards the owners

The relationship between dogs and their owners is characterized by an affective and enduring bond. It has been suggested that oxytocin might be the underlying mechanism driving this relationship, however evidence is mixed. In this study we tested whether intranasally administered oxytocin (compared to saline) would influence dogs' behavioural synchrony and shared attention towards their owners. Each individuals' pre and post administration oxytocin concentrations (measured in urine) were included in the analyses. Urinary oxytocin concentrations after administrations were positively associated with dogs' duration of social proximity and looking behaviours towards their owners supporting the role of oxytocin in modulating dogs' human-directed social behaviours.

Turning preference in dogs: North attracts while south repels

It was shown earlier that dogs, when selecting between two dishes with snacks placed in front of them, left and right, prefer to turn either clockwise or counterclockwise or randomly in either direction. This preference (or non-preference) is individually consistent in all trials but it is biased in favor of north if they choose between dishes positioned north and east or north and west, a phenomenon denoted as "pull of the north". Here, we replicated these experiments indoors, in magnetic coils, under natural magnetic field and under magnetic field shifted 90° clockwise. We demonstrate that "pull of the north" was present also in an environment without any outdoor cues and that the magnetic (and not topographic) north exerted the effect. The detailed analysis shows that the phenomenon involves also "repulsion of the south". The clockwise turning preference in the right-preferring dogs is more pronounced in the S-W combination, while the counterclockwise turning preference in the left-preferring dogs is pronounced in the S-E combination. In this way, south-placed dishes are less frequently chosen than would be expected, while the north-placed dishes are apparently more preferred. Turning preference did not correlate with the motoric paw laterality (Kong test). Given that the choice of a dish is visually guided, we postulate that the turning preference was determined by the dominant eye, so that a dominant right eye resulted in clockwise, and a dominant left eye in counterclockwise turning. Assuming further that magnetoreception in canines is based on the radical-pair mechanism, a "conflict of interests" may be expected, if the dominant eye guides turning away from north, yet the contralateral eye "sees the north", which generally acts attractive, provoking body alignment along the north-south axis.

Cortisol Levels of Shelter Dogs in Animal Assisted Interventions in a Prison: An Exploratory Study

Simple Summary

Animal Assisted Interventions (AAI) are growing in popularity among professionals of psychological therapies due to their clear benefit for human health. However, to date, little attention has been paid to the welfare of the animals involved in the interventions. In this study we evaluated the potential impact of such activities on the welfare of dogs living in a kennel, which had weekly interactions with inmates held at a prison. To assess their stress levels, we analyzed their physiological response to a stressful situation by measuring the cortisol levels in saliva samples. We found a significant decrease in cortisol concentration at the end of the AAI program measured in the dogs’ living environment (i.e., kennel), which suggests a positive effect of the AAI activities on the welfare of kennel dogs. The results also suggest that transportation from the kennel to the prison could be perceived as a stressful event since it significantly increased dogs’ cortisol levels. Therefore, particular care should be taken in the management of this phase.

Abstract

Previous studies regarding the Animal Assisted Interventions (AAI) have mainly focused on the beneficial effects of human–animal interactions on human health; whereas the impact of such activities on the welfare of the animals involved has received limited attention. So far, few studies have addressed this issue by evaluating the physiological and behavioral reactions of therapy dogs during the interventions. The aim of this study was to evaluate the potential effect of AAI on the cortisol levels of shelter dogs. Five dogs participated in weekly AAI working activities with adult inmates held at a prison of the South of Italy for two months. Saliva samples were collected every two weeks in three conditions: at the kennel (baseline), after transportation and at the end of the working sessions. The results revealed a significant decrease in the cortisol baseline at the end of the AAI program, suggesting that the activities carried out with humans and in a different environment could improve the welfare of dogs housed in kennels. Moreover, we found that transportation significantly increased subjects’ cortisol levels, suggesting that it is a critical phase that deserves particular care.

Odour-Evoked Memory in Dogs: Do Odours Help to Retrieve Memories of Food Location?

Simple Summary

The ability of odors to evoke past memories has been widely reported in humans. Although olfaction is generally considered as the most important sense in dogs, little is known about its relationship with memory in this species. To investigate this issue, we trained dogs to memorize the location of five rewards while a specific odor (i.e., vanilla) was dispersed in the environment. After 24 h delay, dogs were divided in three groups, which performed two trials of the same spatial task in different conditions. The first group received a control odor (i.e., apple) in the first trial and the vanilla odor in the second trial; vice versa, the second group was exposed to the vanilla odor in the first test and to the apple odor in the second one. The third group, instead, performed the tests with no odors. We found that the exposure to vanilla odor significantly improved dogs’ performance in the spatial task, suggesting that the odor aided dogs to recall specific and detailed memories originally formed in its presence.

Abstract

The ability of odors to spontaneously trigger specific memories has been widely demonstrated in humans. Although increasing evidence support the role of olfaction on dogs’ emotions and cognitive processes, very little research has been conducted on its relationship with memory in this species. The present study aimed at investigating the role of olfaction in the recall of detailed memories originally formed in the presence of a specific odor (i.e., vanilla). To test this, three groups of participants were trained with the same spatial learning task while a specific odor (i.e., vanilla) was dispersed in the testing room. Subjects were then divided in three experimental groups and after 24 h delay, they were presented with the same spatial task. The first group (Group 1) performed the task in the presence of a novel odor (i.e., control), whereas the second (Group 2) and the third group (Group 3) carried out the test in the presence of the vanilla odor and no odor (Group 3), respectively. After a brief delay, the test was presented again to the three groups of dogs: subjects of Group 1 were now tested in the presence of the vanilla odor, whereas the Group 2 was tested with the control odor. The Group 3 received no odor in both tests. A significant improvement of dogs’ performance was registered in the control-vanilla odors condition (Group 1), suggesting that the exposure to the odor presented at the encoding time would prompt the recall of spatial memories in dogs.