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Spatial judgement bias tests (JBTs) can involve teaching animals that a bowl provides a reward in one location but does not in another. The animal is then presented with the bowl placed between the rewarded and the unrewarded locations (i.e., ambiguous locations) and their latency to approach reflects expectation of reward or 'optimism'. Some suggest that greater 'optimism' indicates better welfare. Performance in JBTs, however, may also indicate a learning history independently from welfare determinants. We hypothesized that dogs' 'optimism' in a follow-up JBT may be impacted by a learning treatment involving additional trials of a different discrimination task. Once enrolled, companion dogs (n = 16) were required to complete three study phases: (1) a pre-treatment JBT, (2) a learning treatment, and (3) a post-treatment JBT. During the JBTs, dogs were presented with five locations: one rewarded, one unrewarded, and three ambiguous (all unrewarded). Dogs were randomly assigned to a trial-based learning task-a nose-touch to the palm of the hand. In the Experimental discrimination treatment phase (n = 8), dogs were presented with two hands in each trial and only rewarded for touching one specific hand. In the Control treatment phase (n = 8), dogs were presented with one hand per trial in alternating sequence and were yoked to dogs in the Experimental group to receive the same number of rewarded and unrewarded trials (to control for possible frustration). Using a repeated measures mixed model with JBT repeated within dog, we found no difference in the change in approach latency to the ambiguous locations between the dogs across treatments. 'Optimism' as measured in this JBT was not altered by the additional discrimination trials used in our study., (© 2024. The Author(s).)

Introduction: The aim of the present study was to determine the views and thoughts of dog owners in Türkiye on animal welfare. The research material consisted of data obtained from face-to-face surveys with 172 randomly selected dog owners. Half of the dog owners (54,7 %) were aware of the concept of animal welfare, and almost two-thirds (61,6 %) organized their dogs' living spaces according to animal welfare principles. Participants most associated the concept of animal welfare with the concept of animal quality of life (47,7 %). Gender (p.

Objective: To investigate the prevalence of firework-associated fear in dogs in Sydney, owner perception of their dog's response to fireworks, perceived efficacy of interventions to manage fearful behaviours and the frequency of dog owners seeking professional advice for these behaviours., Methods: Dog owners in the Greater Sydney area were invited to complete an anonymous online survey., Results: From 387 valid responses, 44.4% (171 of 385) reported their dogs were fearful of fireworks. The most common fear-related behaviour was seeking an owner or caretaker (120 of 161, 74.5%). Most owners responded by bringing their dog inside or trying to comfort or reassure their dog. Only 22.5% of owners sought professional advice for their dog's fear of fireworks, but of these, 65.5% considered that advice to be effective. Source and breed group were significantly associated with fear of fireworks (P = 0.011, P = 0.036 respectively). Fear of fireworks was also significantly associated with fear of thunder (P < 0.0001), gunshots (P < 0.0001) and vehicles (P = 0.0009)., Conclusion: Fear of fireworks and other loud noises negatively impacts canine welfare, yet only a small percentage of owners sought professional advice. There is scope for veterinarians to educate owners and raise awareness about the identification and management of noise-associated fear and reduce the risk of escalation of fearful behaviours., (© 2024 The Author(s). Australian Veterinary Journal published by John Wiley & Sons Australia, Ltd on behalf of Australian Veterinary Association.)

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., (© 2024. The Author(s).)

Georgina Mills discusses research into the effects of human stress on dogs, and how this might lead to them being more pessimistic., (© 2024 British Veterinary Association.)

Citizen science approaches have grown in popularity over the years, partly due to their ability to reach a wider audience and produce more generalizable samples. In dogs, these studies, though, have been limited in their controls over materials or experimental protocols, with guardians typically reporting results without researcher supervision. Over two studies, we explored and validated a synchronous citizen science approach. We had dog guardians act as experimenters while being supervised by a researcher over Zoom. In study 1, we demonstrated that synchronous citizen science produced equivalent levels of performance to in-lab designs in a choice task. Consistent with past in-lab research, dogs selected a treat (vs. an empty plate) in a two-alternative forced-choice task. In study 2, we showed that Zoom methods are also appropriate for studies utilizing looking time measures. We explored dogs' looking behaviors when a bag of treats was placed in an unreachable location, and dogs' guardians were either attentive or inattentive while dogs attempted to retrieve the treats. Consistent with past work, dogs in the attentive condition looked at their guardian for longer periods and had a shorter latency to first look than dogs in the inattentive condition. Overall, we have demonstrated that synchronous citizen science studies with dogs are feasible and produce valid results consistent with those found in a typical lab setting., (© 2024. The Author(s).)

In this column, a dog owner discusses why she thinks the criticism levelled at vets as a consequence of the CMA review is unfair., (© 2024 British Veterinary Association.)

A recent study has used scalp-recorded electroencephalography to obtain evidence of semantic processing of human speech and objects by domesticated dogs. The results suggest that dogs do comprehend the meaning of familiar spoken words, in that a word can evoke the mental representation of the object to which it refers., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)

An important question in the study of canine cognition is how dogs understand humans, given that they show impressive abilities for interacting and communicating with us. In this review, we describe and discuss studies that have investigated dogs' perspective-taking abilities. There is solid evidence that dogs are not only sensitive to the gaze of others, but also their attention. We specifically address the question whether dogs have the ability to take the perspective of others and thus come to understand what others can or cannot perceive. From the latter, they may then infer what others know and use this representation to anticipate what others do next. Still, dogs might simply rely on directly observable cues and on what they themselves can perceive when they assess what others can perceive. And instead of making inferences from representations of others' mental states, they may have just learned that certain behaviours of ours lead to certain outcomes. However, recent research seems to challenge this low-level explanation. Dogs have solved several perspective-taking tasks instantly and reliably across a large number of variations, including geometrical gaze-following, stealing in the dark, concealing information from others, and Guesser/Knower differentiation. In the latter studies, dogs' choices between two human informants were strongly influenced by cues related to the humans' visual access to the food, even when the two informants behaved identically. And finally, we review a recent study that found dogs reacting differently to misleading suggestions of human informants that have either a true or false belief about the location of food. We discuss this surprising result in terms of the comprehension of reality-incongruent mental states, which is considered as a hallmark of Theory of Mind acquisition in human development. Especially on the basis of the latter findings, we conclude that pet dogs might be sensitive to what others see, know, intend, and believe. Therefore, this ability seems to have evolved not just in the corvid and primate lineages, but also in dogs., (© 2023. The Author(s).)

In humans, numerical estimation is affected by perceptual biases, such as those originating from the spatial arrangement of elements. Different animal species can also make relative quantity judgements. This includes dogs, who have been proposed as a good model for comparative neuroscience. However, dogs do not show the same perceptual biases observed in humans. Thus, the exact perceptual/cognitive mechanisms underlying quantity estimations in dogs and their degree of similarity with humans are still a matter of debate. Here we explored whether dogs are susceptible to the connectedness illusion, an illusion based on the tendency to underestimate the quantity of interconnected items. Dogs were first trained to choose the larger of two food arrays. Then, they were presented with two arrays containing the same quantity of food, of which one had items interconnected by lines. Dogs significantly selected the array with unconnected items, suggesting that, like in humans, connectedness determines underestimation biases, possibly disrupting the perceptual system's ability to segment the display into discrete objects. The similarity in dogs' and humans' susceptibility to the connectedness, but not to other numerical illusions, suggests that different mechanisms are involved in the estimation of quantity of stimuli with different characteristics., (© 2021. The Author(s).)

Separation related disorder in dogs is a multi-faceted phenomenon. Dogs can react to the absence of their owner due to different inner states such as fear, panic or frustration. We hypothesized that dogs that are prone to frustration or fearfulness in other contexts would show a different behavioral response to separation from the owner. We investigated the association between inner states in different contexts and separation behaviors by combining a questionnaire with a separation test. Fear-related questionnaire components were rather associated with whining and the absence of barking. Dogs that received higher scores in the demanding component of the questionnaire, which might be in association of the frustration threshold of the dog, barked more and were more likely to scratch the door. Finally, dogs that were more prone to phobic reactions whined somewhat more and tried to escape. We provide empirical support for the assumption that separation-related behavioral responses of dogs might be triggered by different emotions., (© 2021. The Author(s).)

Domestic dogs are trained using a range of different methods, broadly categorised as reward based (positive reinforcement/negative punishment) and aversive based (positive punishment/negative reinforcement). Previous research has suggested associations between use of positive punishment-based techniques and undesired behaviours, but there is little research investigating the relative welfare consequences of these different approaches. This study used a judgement bias task to compare the underlying mood state of dogs whose owners reported using two or more positive punishment/negative reinforcement based techniques, with those trained using only positive reinforcement/negative punishment in a matched pair study design. Dogs were trained to discriminate between rewarded and unrewarded locations equidistant from a start box, and mean latencies recorded. Their subsequent latency to intermediate 'ambiguous' locations was recorded as an indication of whether these were perceived as likely to contain food or not. Dogs trained using aversive methods were slower to all ambiguous locations. This difference was significant for latency to the middle (Wilcoxon Z = - 2.380, P = 0.017), and near positive (Wilcoxon Z = - 2.447, P = 0.014) locations, suggesting that dogs trained using coercive methods may have a more negative mood state, and hence that there are welfare implications of training dogs using such methods., (© 2021. The Author(s).)

When dogs interact with humans, they often show appropriate reactions to human intentional action. But it is unclear from these everyday observations whether the dogs simply respond to the action outcomes or whether they are able to discriminate between different categories of actions. Are dogs able to distinguish intentional human actions from unintentional ones, even when the action outcomes are the same? We tested dogs' ability to discriminate these action categories by adapting the so-called "Unwilling vs. Unable" paradigm. This paradigm compares subjects' reactions to intentional and unintentional human behaviour. All dogs received three conditions: In the unwilling-condition, an experimenter intentionally withheld a reward from them. In the two unable-conditions, she unintentionally withheld the reward, either because she was clumsy or because she was physically prevented from giving the reward to the dog. Dogs clearly distinguished in their spontaneous behaviour between unwilling- and unable-conditions. This indicates that dogs indeed distinguish intentional actions from unintentional behaviour. We critically discuss our findings with regard to dogs' understanding of human intentional action., (© 2021. The Author(s).)

Background: The Dangerous Dogs Act (DDA) is considered among the most controversial pieces of legislation ever passed in the UK. Its effectiveness and how it works in practice, up until a dog and its owner are charged, has been subjected to considerable analysis. However, there has been little examination of how the DDA works after charging, nor of how courts are interpreting it., Method: We accessed legal cases from 1992 to 2019, the period in which the DDA has been in force. Each case was examined from a legal and ethical perspective, using doctrinal legal methodology and the principlism approach to ethics described by Beauchamp and Childress., Results: Analysis showed that while improvements to the function of the act have been made, substantial legal and ethical failings remain, particularly with Section 1 and the therein breed specific legislation (BSL)., Conclusion: Legal failings could be partially resolved by removing the reversed burden of proof placed on dog owners and allowing a change of ownership for banned breeds. However, ethical failings could only be resolved through the abolition of BSL. Further study into whether judicial bias exists against certain breeds found to be dangerously out of control is warranted., (© 2021 The Authors. Veterinary Record published by John Wiley & Sons Ltd on behalf of British Veterinary Association.)

Domestic dogs have been shown to reciprocate help received from conspecifics in food-giving tasks. However, it is not yet known whether dogs also reciprocate help received from humans. Here, we investigated whether dogs reciprocate the receipt of food from humans. In an experience phase, subjects encountered a helpful human who provided them with food by activating a food dispenser, and an unhelpful human who did not provide them with food. Subjects later had the opportunity to return food to each human type, in a test phase, via the same mechanism. In addition, a free interaction session was conducted in which the subject was free to interact with its owner and with whichever human partner it had encountered on that day. Two studies were carried out, which differed in the complexity of the experience phase and the time lag between the experience phase and test phase. Subjects did not reciprocate the receipt of food in either study. Furthermore, no difference was observed in the duration subjects spent in proximity to, or the latency to approach, the two human partners. Although our results suggest that dogs do not reciprocate help received from humans, they also suggest that the dogs did not recognize the cooperative or uncooperative act of the humans during the experience phase. It is plausible that aspects of the experimental design hindered the emergence of any potential reciprocity. However, it is also possible that dogs are simply not prosocial towards humans in food-giving contexts., Competing Interests: The authors have declared that no competing interests exist.

Forming eye contact is important in dog-human communication. In this study we measured what factors affect dogs' propensity for forming eye contact with an experimenter. We investigated the effect of [1] cephalic index (head shape's metric, indicator of higher visual acuity at the centre of the visual field), [2] breed function (visual cooperativeness), [3] age and [4] playfulness with strangers in 125 companion dogs. Cephalic index was measured individually and analysed as a continuous variable. Results showed that [1] dogs with a higher cephalic index (shorter head) established eye contact faster. Since cephalic index is highly variable even within a breed, using artificial head shape groups or breed average cephalic index values is not recommended. [2] Breed function also affected dogs' performance: cooperative breeds and mongrels established eye contact faster than dogs from non-cooperative breeds. [3] Younger dogs formed eye contact faster than older ones. [4] More playful dogs formed eye contact faster. Our results suggest that several factors affect dogs' interspecific attention, and therefore their visual communication ability.

Animal shelters around the US are commonly overpopulated, and canine-specific behavioral rehabilitation opportunities within shelters are limited. The current project explored the possibility of integrating a canine-training program into the academic undergraduate Psychology curriculum. Students enrolled in the "Canine Learning and Behavior" class at Saint Francis University fostered and trained a total of 10 shelter dogs throughout three academic semesters, and the effectiveness of the program on the behavior of the dogs was evaluated. Findings demonstrated that the behavioral repertoire of all trained dogs improved, as assessed using a 10-item questionnaire tailored to the American Kennel Club "Canine Good Citizen" (AKC-CGC) test. Results also demonstrated that most dogs passed the AKC-CGC test conducted by a certified evaluator, and that all dogs were successfully adopted into their forever homes. The implications, limitations, and future directions of the study are discussed.

Background: Brain size has been associated with intelligence of various orders and families of animals, leading to the concept of encephalization. Brain size scales with body weight between species within mammals to approximately the 0.67 power. However, within species, this scaling exponent appears to be much smaller (approximately 0.27 power)., Aim: We examined whether this relationship has persisted in dogs over the 120 years since this was originally observed., Methods: Comparative cross-sectional study of magnetic resonance imaging (MRI) data obtained from 127 dogs, compared to historical data from 157 dogs and 24 non-dog canid species., Results: Brain size in dogs measured by MRI had a scaling exponent virtually identical to that observed previously (0.24 vs. 0.26). However, the proportionality constant was smaller, suggesting that dogs in the study cohort had relatively smaller brains than the historical cohort. Absolute brain size appeared to have both a lower and upper limit in dogs. When compared to non-dogs canids, the most appropriate "representative" size for a "typical dog" when examining allometric scaling across Canidae appeared to be approximately 10-15 kg., Conclusions: We interpreted the slight reduction in relative brain size to be a function of increased obesity in the study cohort compared to dogs examined 120 years ago. Further, we suggest that dog brains have a finite lower size limit. Finally, concepts of encephalization should not be applied to dogs., Competing Interests: The authors have no conflicts of interest to declare.

Background: Noise aversion is a common behavioural disorder in dogs; affected dogs show fear behaviours in response to noise stimuli. Pharmacological treatment is effective for many dogs; clinical reports suggest anxiolytic treatment lowers the need for treatment over time. We aimed to evaluate the effect of dexmedetomidine oromucosal gel for dogs with noise aversion over a series of noise events. Furthermore, we evaluated burden of care for owners of dogs with noise aversion via questionnaire., Methods: Owners of enrolled dogs completed records for 10 noise events indicating whether their dog received dexmedetomidine gel and pretreatment and post-treatment anxiety scores; adverse events were noted. Owners were queried about burden of care., Results: Twenty-two client-owned dogs completed recordings for 10 events. Logistic regression results showed a significant effect for time of event with decreased probability of receiving treatment for subsequent events (OR=0.75, P=0.0017). Within an event, significant improvement in anxiety was seen (median improvement 11 points; paired Wilcoxon; P<0.0001). We found overall burden of care was manageable, yet many owners agreed with statements regarding frustration (42 per cent), stress (46 per cent), guilt (42 per cent) and sadness (75 per cent) about their dog's condition., Conclusions: Repeated use of dexmedetomidine gel for noise events resulted in decreased need for administration. Burden of care is important to discuss with clients., Competing Interests: Competing interests: SC is an employee of Zoetis, and MEK is an employee of Orion Corporation. MG has been a paid consultant in veterinary behavioural medicine., (© British Veterinary Association 2020. Re-use permitted under CC BY-NC. No commercial re-use. Published by BMJ.)

It is now widely agreed that a positive affective state is a crucial component of animal well-being. The judgment bias test represents a widespread tool used to assess animals' optimistic/pessimistic attitude and to evaluate their emotional state and welfare. Judgment bias tests have been used several times with dogs (Canis familiaris), in most cases using a spatial test with a bowl placed in ambiguous positions located between a relatively positive trained location (P) which contains a baited bowl and a relatively negative trained location (N) which contains an empty bowl. The latency to approach the bowl in the ambiguous locations is an indicator of the dog's expectation of a positive/negative outcome. However, results from such tests are often inconclusive. For the present study, the judgment bias test performance of 51 shelter dogs and 40 pet dogs was thoroughly analysed. A pattern emerged with shelter dogs behaving in a more pessimistic-like way than pet dogs. However, this difference between the two populations was detected only when analysing the raw latencies to reach the locations and not the more commonly applied adjusted score (i.e. average latency values). Furthermore, several methodological caveats were found. First of all, a non-negligible percentage of dogs did not pass the training phase, possibly due to the experimental paradigm not being fully suited for this species. Second, results showed a high intra-dog variability in response to the trained locations, i.e. the dogs' responses were not consistent throughout the test, suggesting that animals may not have fully learned the association between locations and their outcomes. Third, dogs did not always behave differently towards adjacent locations, raising doubts about the animals' ability to discriminate between locations. Finally, a potential influence of the researcher's presence on dogs' performance emerged from analyses. The implications of these findings and potential solutions are discussed., Competing Interests: The authors have declared that no competing interests exist.

In humans, age-related changes in personality occur in a non-random fashion with respect to their direction, timing, and magnitude. In dogs, there are still gaps in our knowledge about the detailed dynamics of age-related personality changes. We analysed the personality of 217 Border collies aged from 0.5 to 15 years both cross-sectionally and longitudinally using a test battery, to specify age periods when changes most prominently occur, assess the magnitude of changes, and analyse individual differences in personality change. We found that similar to humans, changes in personality occur unevenly during the dogs' life course, however, their dynamics seems to be specific for each trait. Activity-independence decreased mostly from puppyhood (0.5-1 years) to adolescence (> 1-2 years), then continued to decrease in a slowing rate. Novelty seeking did not change markedly until middle age (> 3-6 years), then showed a steady linear decrease. Problem orientation increased strongly until middle age then showed no marked changes in later age periods. We also revealed individual differences in personality change over time, and showed that a few individuals with potential age-related impairments significantly affected the general age trajectory of some traits. These results raise caution against the over-generalisation of global age trends in dogs.

The present study extended functional analysis (FA) methodology to human-directed resource guarding in a dog in an in-home setting. The subject underwent four conditions including control, attention, escape, and tangible, arranged in a modified FA. The results indicated multiply controlled resource guarding (i.e., escape, attention, and tangible functions). The experimenter then conducted a treatment evaluation involving three function-based treatments in a concurrent multiple baseline design. Resource guarding decreased to zero levels in treatments for each maintaining contingency. Treatment effects were maintained when the subject was tested with an owner, with an untrained handler, a highly preferred treat, in an untrained setting, as well as after 2 weeks in the absence of training. Behavior analytic techniques may hold promise for lasting behavior change for resource guarding in domestic dogs, and should be examined in other populations and with other canine problem behavior., (© 2020 Society for the Experimental Analysis of Behavior.)

Serotonin is a neurotransmitter synthesized by the amino acid tryptophan, that has the potential to impact the behaviour and activity of dogs. The objective of this study was to assess the effects of supplemental tryptophan and a 12-week incremental training regimen on the voluntary activity and behaviour of client-owned Siberian Huskies. Sixteen dogs were blocked for age, BW and sex and then randomly allocated to either the control or treatment group. Both groups were fed the same dry extruded diet; however, the treatment group were supplemented with tryptophan to achieve a tryptophan: large neutral amino acid ratio of 0.075:1. Once a week, a 5-minute video recording was taken immediately pre- and post- exercise to evaluate dogs' behaviours. Activity monitors were used to record voluntary activity on both training and rest days. Linear regression analysis was used to assess the relationship between training week and time spent performing each behaviour. Additionally, a repeated measure mixed model was used to test differences between diet groups and training week for both behavioural and activity count data. The time spent performing agonistic behaviours prior to exercise was negatively associated with week for treatment dogs (β = -0.32, 95% CI [-0.55, -0.10], P < 0.05) and no change was observed for control dogs (β = -0.13, 95% CI [-0.41, 0.15], P > 0.10). Treatment did not have any effect on activity levels (P > 0.10). For all dogs, locomotive behaviours decreased prior to exercise as weeks progressed (P < 0.05), while run day voluntary activity depended on the distance run that day (P < 0.05). These data suggest that sled dogs experience an exercise-induced reduction in voluntary locomotion in response to both single bouts and repetitive bouts of exercise. Additionally, tryptophan supplementation may decrease agonistic behaviours, without having any effect on voluntary activity., Competing Interests: Eve Robinson and James R. Templeman were partly funded by Champion Pet Food to complete the research, in association with the Mitacs Accelerate program. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

Social structure creates heterogeneity of interactions between individuals, thus influencing infectious disease spread. The objective of this study was to describe and characterise the social structure of free-roaming dog populations in three communities in the Torres Strait, Australia. Dogs in Kubin, Saibai, and Warraber communities were collared with GPS units that recorded locations at 15 s intervals for up to 1 week, and datasets were obtained from 24 (62% of the dog population), 23 (53%) and 21 (51%) dogs in each community, respectively. An association (potential contact) between dogs was defined as proximity within a spatio-temporal window of 5 m for 30 s. Networks were constructed for each dog population: 1. nodes were individual dogs, and 2. edges were weighted according to the duration of spatio-temporal association between pairs of dogs as a proportion of their simultaneous time monitored. Network statistics were calculated for each population and the robustness of networks to the duration of association between pairs of dogs was assessed in terms of efficiency, degree distribution and fragmentation (number of components). Dog social networks had 'small-world' structures, with characteristic clustering and low average shortest-path length between individuals. Overall, all three networks were highly connected in terms of degree distribution and global and local efficiency, but the median tie strength (2-13.5 min) was low. Centrality and the duration of association (tie-strength) between dogs were significantly different between communities. The Kubin network was least robust to fragmentation when ties of short duration were successively removed (14 components with minimum tie strength of 2 h). In contrast, the Warraber dog network was relatively robust with 7 components at minimum tie strength of 2 h as well as high local efficiency within components. We conclude that whilst infectious disease that requires a short duration of contact for transmission is likely to spread rapidly between and within clusters in all three networks in this study, fragmentation of networks - once ties of short duration are removed - is likely to limit spread of disease that requires a longer duration of direct contact. The network information in this study is useful as a foundation for disease spread modelling and to investigate control strategies such as movement restrictions in dog populations., (Copyright © 2018 Elsevier B.V. All rights reserved.)

We investigated whether dogs remember their spontaneous past actions relying on episodic-like memory. Dogs were trained to repeat a small set of actions upon request. Then we tested them on their ability to repeat other actions produced by themselves, including actions performed spontaneously in everyday situations. Dogs repeated their own actions after delays ranging from a few seconds to 1 hour, with their performance showing a decay typical of episodic memory. The combined evidence of representing own actions and using episodic-like memory to recall them suggests a far more complex representation of a key feature of the self than previously attributed to dogs. Our method is applicable to various species, paving the way for comparative investigations on the evolution and complexity of self-representation.

Inequity aversion, the resistance to inequitable outcomes, has been demonstrated in a wide variety of animal species. Inequity aversion was hypothesised to have co-evolved with cooperation but only limited evidence supports this. Dogs provide a suitable model species to test this hypothesis as dogs were previously shown to be inequity averse and dog breeds vary in the extent to which they were selected for cooperativeness. Here, we compared the response of 12 individuals of "cooperative worker" breeds with that of 12 individuals of "independent worker" breeds in the "paw task" previously used to demonstrate inequity aversion in dogs. We also compared the two breed groups' subsequent social behaviours in a food tolerance test and free interaction session. Although subjects in both breed groups were inequity averse, we found no considerable difference between the groups in the extent of the negative response to inequity or in the impact of the inequity on subsequent social behaviours. However, we found differences between the breed groups in the response to reward omission with cooperative breeds tending to work for longer than independent breeds. Additionally, in the free interaction session, individuals of cooperative breeds spent more time in proximity to their partner in the baseline condition than individuals of independent breeds. Overall, our results do not provide support for the hypothesis that inequity aversion and cooperation co-evolved. However, they illuminate potential differences in selection pressures experienced by cooperative worker and independent worker dog breeds throughout their evolutionary history., Competing Interests: The authors have declared that no competing interests exist.

Background: Behavioural case loads may vary due to cultural differences, and so it is important to know how these differ with geography., Methods: One hundred and eighty dog cases referred to a veterinary behaviourist in São Paulo (Brazil) during the period of 2008-2014 are described., Results: Aggression against people was the most common behavioural complaint (22.2 per cent of the cases), followed by apparent fears and phobias (13.3 per cent). Forms of aggression against other dogs (12.2 per cent) and repetitive behaviours (11.1 per cent) were third and fourth most frequent, respectively. Female and male patients were equally reported (47.6 and 52.4 per cent, respectively). These results differ slightly from the findings of other international studies, in which aggression was the main behavioural complaint with fears and phobias less common., Conclusion: Regional demographic reviews of the case loads of veterinary behaviour specialists help the profession recognise the problems of most concern to pet owners in a given area and thus local priorities, as well as opening up the potential to generate new hypotheses relating to the reasons for regional differences., Competing Interests: Competing interests: None declared., (© British Veterinary Association 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Social play is a window on cognitive and communicative abilities of species. Inter-specific play, in particular, is a fertile venue to explore the capacity to correctly perceive and interpret signals emitted by partners. Up to now, most studies have focussed on dog-human play due to the important implications such studies have in understanding the peculiar relationship we establish with our pets. Here, we focussed on social play between dogs and horses. By using a set of specific keywords (dog, horse, play, friend) we selected 20 videos of dog-horse social play (with each session lasting >30 s) from the open video-sharing website YouTube. We described the behavioural patterns composing each session by defining analogous and species-specific patterns shown by dogs and horses. The rates of self-handicapping and variability in playful actions did not differ between the two interacting subjects thus suggesting well-balanced playful tactics. The Relaxed Open Mouth (ROM, a widespread playful facial expression in mammals) was also similarly performed by dogs and horses. The Rapid Facial Mimicry (RFM) is an automatic, fast response in which individuals mimic others' expressions (less than 1 s) that seems to have a role in mood sharing during social interactions. The dogs and horses under study showed a stronger and rapid mimicry response (less than 1 s) after perceiving ROM than after perceiving an attempt to bite (a play pattern resembling ROM in its motor performance). Taken together, our results suggest that, despite the difference in size, the phylogenetic distance, and differences in the behavioural repertoire, dogs and horses are able to fine-tune their actions thus reducing the probability of misunderstanding and escalating into aggression. One of the future challenges is to explore the role of ontogenetic pathways and familiarity in shaping inter-specific communicative ability of animals that can be at the basis of a universal language of play., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Trypanosoma cruzi is a zoonotic protozoan parasite vectored by triatomine insects that are endemic to the Americas, including the southern United States. Surveillance of domestic dogs for T. cruzi exposure allows for the determination of geographic regions of transmission that are relevant for human and animal health. The U.S. Department of Homeland Security (DHS) working dogs provide critical security and detection services across the country, and many train or work in the southern United States, where they are at risk for T. cruzi exposure. We sampled blood from 1,610 working dogs (predominantly Belgian Malinois, German shepherds, and Labrador retrievers) from six task forces (including the Transportation Security Administration, Customs and Border Protection, Secret Service, and more) and two canine training centers across 41 states from 2015 to 2018. Canine sera that were reactive on at least two independent serological assays were considered positive for anti- T.-cruzi antibodies. In addition, up to three independent polymerase chain reaction (PCR) assays were used to detect and type T. cruzi DNA. Overall seroprevalence was 7.5%, and four dogs (0.25%, n = 1,610) had detectable parasite DNA in the blood, comprising parasite discrete taxonomic units (DTUs) TcIV and a coinfection of TcI/TcIV. Dogs that worked within versus outside of the geographic range of established triatomines showed comparable seroprevalence (7.3% and 9.2%, respectively; P = 0.61). Determining the prevalence of T. cruzi in these working dogs and looking at spatially associated risk factors have practical implications for disease risk management and could assist with improved control measures to protect both animal and human health.

Categorization has been tested in non-human animals after extensive training procedures under laboratory conditions and it is assumed that in non-primate species categorization relies on perceptual similarity. We report evidence of the ability to categorize objects in absence of specific training in a family dog with vocabulary knowledge of multiple toys, including exemplars of 4 categories. Our experimental design was devised to test categorization in absence of specific training and based on the spontaneously learned vocal labels of the categories, a condition that mirrors human studies more than previous experiments on non-human animals. We also observed that the dog's categorization skills were more accurate when, prior to the categorization test, she was given the opportunity to play with the novel exemplars, suggesting that category representations arise not only from physical resemblance, but also from objects' affordances (function).

The presence of pictures of eyes reduces antisocial behaviour in humans. It has been suggested that this 'watching-eye' effect is the result of a uniquely human sensitivity to reputation-management cues. However, an alternative explanation is that humans are less likely to carry out risky behaviour in general when they feel like they are being watched. This risk-aversion hypothesis predicts that other animals should also show the watching-eye effect because many animals behave more cautiously when being observed. Dogs are an ideal species to test between these hypotheses because they behave in a risk-averse manner when being watched and attend specifically to eyes when assessing humans' attentional states. Here, we examined if dogs were slower to steal food in the presence of pictures of eyes compared to flowers. Dogs showed no difference in the latency to steal food between the two conditions. This finding shows that dogs are not sensitive to watching-eyes and is not consistent with a risk-aversion hypothesis for the watching-eye effect.

Social dominance is an important and widely used concept, however, different interpretations have led to ambiguity in the scientific literature and in popular science. Even though in ethology dominance is an attribute of dyadic encounters, and not a characteristic of the individual, 'dominance' has often been referred to as a personality trait in animals. Since few studies have specifically examined the link between personality traits and dominance status, we investigated this in dogs living in multi-dog households using a questionnaire, which required owners to specify whether the dog had a dominant or submissive status, and comprised items of both the features of the individual (i.e. personality traits) and previous social experience (interactions with group members and strangers). Four distinct personality factors emerged from 23 behavioural items by principal component analysis, labelled as assertiveness, trainability, intraspecific aggression and independence. Binomial logistic regression was used to examine how the demographic information of the dogs and the personality factors predicted the owner's estimate of the dog' status as dominant or submissive. The personality factor assertiveness accounted for 34% of the variance in dominance status, trainability 5% and dog age contributed 4%. Dogs perceived as dominant scored more highly on the factors assertiveness and trainability, which can help explain why 'dominance' has often been suggested to be a personality trait, rather than a dyad-specific social status according to different traditions in behavioural research. Similar to the 'social dominance' trait in humans, owner ascribed dominance showed a quadratic trajectory in cross-sectional mean change across the lifespan, increasing during adulthood and then maintaining high levels until old age. Overall, our study proposes a multifactorial background of dominance relationships in pet dogs, suggesting that not only previous experience of social interactions between individuals but also age and personality traits influence owner perceived dominance status in multi-dog households., Competing Interests: The authors have declared that no competing interests exist.

In Mexico, toxocariasis, like some other parasitosis in humans, is not a disease of conventional surveillance or immediate notification. Seroprevalence studies are scarce, six dealing with paediatric populations and eight dealing with adults; the reports were only from four states in Mexico. There were 1596 children, and the seroprevalence was 13.8%. In the case of adults, there were 1827 subjects, and seroprevalence was 4.7%. There is a significant positive association between seroprevalence and the paediatric population P<0.0001 (OR, 3.285; 95% CI, 2.541-4.279). It is advisable to perform competitive ELISAs and add another diagnostic test, such as Western blot or the detection of circulating antigens to reduce diagnostic uncertainty. This neglected parasitosis can be confused with retinoblastoma. Therefore, there is a risk of ocular enucleation. It is necessary to sensitise the authorities of the Ministry of Health and decision-makers, to provide economic support for epidemiological surveillance of this zoonotic parasite., (© 2020 Elsevier Ltd All rights reserved.)

Spaying of female dogs is a widespread practice, performed primarily for population control. While the consequences of early spaying for health are still being debated, the consequences for behaviour are believed to be negligible. The current study focused on the reported behaviour of 8981 female dogs spayed before 520 weeks (ten years) of life for reasons other than behavioural management, and calculated their percentage lifetime exposure to gonadal hormones (PLGH) as a proportion of their age at the time of being reported to the online Canine Behavioral Assessment and Research Questionnaire (C-BARQ). We found that 23 behaviours differed between entire and spayed dogs, of which 12 were associated with PLGH and 5 with age-at-spay (AAS). Two behaviours, chewing and howling, were significantly more likely in dogs with longer PLGH. In contrast, longer PLGH was associated with significantly reduced reporting of 10 (mostly unwelcome) behaviours. Of these, one related to fearfulness and three to aggression. The current data suggest that dogs' tendency to show numerous behaviours can be influenced by the timing of spaying. They indicate how female dog behaviour matures when gonadal hormones are allowed to have their effect. The differences reported here between undesirable behaviours of spayed and entire dogs were in the range of 5.33% and 7.22%, suggesting that, for some dogs, partial or complete denial of maturation may reduce howling and chewing and improve retrieval and recall, but have other undesirable consequences. Veterinarians may take these data into account to discuss the risks and benefits of spaying with clients, and the timing of the procedure., Competing Interests: The authors have declared that no competing interests exist.

The English version of the Positive and Negative Activation Scale (PANAS) is a useful tool for the assessment of dog temperament, helping to identify highly sensitive individuals that could be at risk of developing fears, phobias and anxiety problems, and potentially depressive states. This study evaluated the association between dogs' and owners' characteristics and dog temperament in Brazil. To accomplish this, we adapted and validated a Portuguese language version of PANAS for dogs. Data from 1744 owner-dog dyads were analysed and a two-factor structure similar to the original PANAS was revealed that met the requirements for validity and internal consistency. We found that dogs owned by women, neutered dogs and those who live in single-dog households show higher negative activation. Moreover, the older the owner, the less the negative activation for dogs that are bought. We also found that the older the dog, the less the positive activation, but this score is higher in dogs that sleep inside the house. Interestingly, mixed-breed dogs scored higher for both negative and positive emotional activation compared to purebreds. These findings alongside the particular profile of dogs in Brazil, including its large population of mixed-breed, emphasise the value of cross-cultural investigations in order to develop a full understanding of dog behaviour.

In comparison to non-human animals, humans are highly flexible in cooperative tasks, which may be a result of their ability to understand a partner's role in such interactions. Here, we tested if wolves and dogs could flexibly adjust their behaviour according to whether they needed a partner to solve a cooperative loose string-pulling paradigm. First, we presented animals with a delay condition where a human partner was released after the subject so that the animal had to delay pulling the string to enable coordinated pulling with the human partner. Subsequently, we investigated whether subjects would recruit a partner depending on whether they could operate the apparatus alone, or help from a partner was required. Both wolves and dogs successfully waited in the delay condition in 88% of the trials. Experimental subjects were also successful in recruiting a partner, which occurred significantly more often in the cooperation trials than in the solo pulling condition. No species differences were found in either experiment. These results suggest that both wolves and dogs have some understanding of whether a social partner is needed to accomplish a task, which enables behavioural coordination and cooperation.

Inhibitory control is a term used to envelop a collection of processes that allow an organism to refrain from engaging in an inappropriate prepotent or responsive behavior. Studies have examined the propensity of inhibitory control by nonhuman animals, from the cognitively complex processes involved in self-control to potentially less cognitively taxing processes such as motoric self-regulation. Focusing on canines, research has suggested that the domestication process as well as experiences during ontogeny contribute to inhibitory control. Diet may also play an important role in an individual's ability to self-regulate. This study examined this possibility by investigating motoric self-regulation in sled dogs, using three well-established tasks (i.e., A-not-B Bucket, Cylinder, and A-not-B Barrier tasks), performed after consumption of one of three dietary treatments with different glycemic index values. We also compared the performance of sled dogs during these tasks with results previously obtained from pet dogs. Overall, the results show many similarities in the performance of sled dogs and pet dogs on the motoric self-regulation tasks, with the notable exception that sled dogs may have a stronger spatial perseveration during the A-not-B Bucket task. Previous research findings reporting a lack of correlation among these tasks are also supported. Finally, during the early postprandial phase (period after consumption), dietary treatments with different glycemic index values did not influence self-regulatory performance for sled dogs.

Previous research proves dogs' outstanding success in socio-communicative interactions with humans; however, little is known about other domestic species' interspecific skills when kept as companion animals. Our aim was to assess highly socialized young miniature pigs' spontaneous reactions in interactions with humans in direct comparison with that of young family dogs. All subjects experienced similar amount of socialization in human families. In Study 1, we investigated the appearance of human-oriented behaviours without the presence of food (Control condition) when a previously provided food reward was withheld (Food condition). In Study 2, we measured responsiveness to two types of the distal pointing gesture (dynamic sustained and momentary) in a two-way object choice test. In the Control condition of Study 1, the duration of pigs' and dogs' orientation towards and their frequency of touching the human's body was similar. In the Food condition, these behaviours and orienting to the human's face were intensified in both species. However, pigs exhibited face-orientation to an overall lesser extent and almost exclusively in the Food condition. In Study 2, only dogs relied spontaneously on the distal dynamic-sustained pointing gesture, while all pigs developed side bias. The results suggest that individual familiarization to a human environment enables the spontaneous appearance of similar socio-communicative behaviours in dogs and pigs, however, species predispositions might cause differences in the display of specific signals as well as in the success of spontaneously responding to certain types of the human pointing gestures.

Dog aggression directed towards humans is a common and serious behavioral and public health issue. This cross-sectional study was designed to gain insights into U.S. small animal veterinarians' views and experiences with the most common dog breeds in the U.S., dog aggression, and breed-specific legislation. An electronic survey was distributed via email to an online veterinary community, and responses were summarized and compared by means of χ 2 and Cochran-Mantel-Haenszel tests. Most respondents were concerned about the risks of dog bite injuries, but the majority were not in favor of banning specific breeds of dogs in order to enhance public safety. When participants rated the perceived bite risk associated with popular dog breeds, Chow Chows were perceived as the highest risk, with pit bull types categorized as a moderate risk. Golden Retrievers were seen as the most appropriate for families with children. Public education about animal behavior was the most frequently endorsed policy intervention to increase public safety. These findings suggest that most veterinarians feel that banning an entire dog breed is not an effective way to ensure human safety. Instead, most respondents endorsed alternative initiatives, such as public education and stricter leash laws, to reduce the risk of dog bites., Competing Interests: The authors declare no conflict of interest.

Canine rabies was endemic pre-urbanisation, yet little is known about how it persists in small populations of dogs typically seen in rural and remote regions. By simulating rabies outbreaks in such populations (50-90 dogs) using a network-based model, our objective was to determine if rabies-induced behavioural changes influence disease persistence. Behavioural changes-increased bite frequency and increased number or duration of contacts (disease-induced roaming or paralysis, respectively)-were found to be essential for disease propagation. Spread occurred in approximately 50% of model simulations and in these, very low case rates (2.0-2.6 cases/month) over long durations (95% range 20-473 days) were observed. Consequently, disease detection is a challenge, risking human infection and spread to other communities via dog movements. Even with 70% pre-emptive vaccination, spread occurred in >30% of model simulations (in these, median case rate was 1.5/month with 95% range of 15-275 days duration). We conclude that the social disruption caused by rabies-induced behavioural change is the key to explaining how rabies persists in small populations of dogs. Results suggest that vaccination of substantially greater than the recommended 70% of dog populations is required to prevent rabies emergence in currently free rural areas., Competing Interests: The authors have declared that no competing interests exist.

Background: A dental therapy dog may help anxious patients in the dental clinic overcome their fear and facilitate the completion of necessary dental care. Dental clinic activities are associated with hazards that may pose potential risks to the health and safety of the dental therapy dog., Objectives: To describe potential hazards associated with risks to health and safety to therapy dogs in dental clinics and to present suggestions for risk minimisation by adopting best practices in dental clinic settings., Materials and Method: Literature searches in Medline, http://Clinicaltrials.gov, and Google Scholar for qualitative and quantitative assessments of occupational hazards and risks in dental clinics, in combination with a review of the reference list of the included studies. Identified hazards and risks were analysed relative to their relevance for the health and welfare of a therapy dog present in a dental clinic setting., Results: Workplace hazards in the dental clinic that apply to both humans and therapy dogs are allergies, sharps injury, eye injury, stress, rhinitis, hearing impairment, and other hazards. Additional concerns associated with risks for the dental therapy dog are situations involving erratic patient behaviour and threats if the patient is an undisclosed disease carrier. Risks to the health and safety of the dental therapy dog in the clinics are present but are low if the dental clinical staff and dog handlers comply with best practices., Conclusions: Best practice includes awareness amongst the clinic staff and the dog handler of all potential hazards in the dental clinic and on how to reduce these hazards as well as adverse events that may scare the dental therapy dog. The dental therapy dog team must be specially trained to work in a dental clinic. Each treatment session has to be exclusively tailored to that specific appointment and the individual patient., Competing Interests: None declared., (© 2019 The Authors. Clinical and Experimental Dental Research published by John Wiley & Sons Ltd.)

Objective:  The aim of this study was to evaluate the contribution of the palmar radiocarpal ligament and the palmar ulnocarpal ligament to canine antebrachiocarpal joint stability., Materials and Methods:  The right carpus of four dog cadavers, free of musculoskeletal pathology, was stripped of muscle. Each specimen was placed into a custom-made joint testing machine and tested at 15° extension, and 0° and 15° flexion. A single motion tracking sensor was fixed to the metacarpal bones. All specimens were tested with all ligaments intact and after transection of the palmar radiocarpal and ulnocarpal ligaments. A range of weights between 0.2 and 2.0 kg was used to test the carpi in three directions (axial, medial/lateral and cranial/caudal) and two moments (pronation/supination and valgus/varus)., Results:  No differences were found between the translations and rotations of the manus relative to the radius and ulna with the ligaments intact and the ligaments transected at any of the carpal angles tested, except at 15° of flexion. Increasing the angle of flexion resulted in a significant increase in cranial and caudal translation of the manus relative to the radius and ulna both in the intact and transected specimens., Clinical Relevance:  Antebrachiocarpal joint position plays a more important role in craniocaudal antebrachiocarpal joint stability than the palmar radiocarpal and ulnocarpal ligaments., Competing Interests: We wish to confirm that there are no known conflicts of interest associated with this publication and there has been no financial support for this work that could have influenced its outcome., (Georg Thieme Verlag KG Stuttgart · New York.)

The success of the dog as a companion animal has undeniably led to a shift in dog breeding practices. While effects of inbreeding or large-scale breeding have given rise to numerous studies about potentially related health issues, it remains unclear to what extent behavioural development of dogs is influenced. By investigating the environment of puppies while at the breeder, the authors aimed to make an inventory of current practices regarding management, socialisation and environmental learning and subsequently to identify potential differences between breeder types. The cross-sectional study, conducted during 2016, revealed considerable variability in environment among dog breeders. Small-scale breeders, and especially occasional breeders (less than 10 adult dogs on-site) provided most enrichment, both social and non-social, by, for instance, providing more outdoor access for pregnant dams and puppies or by providing access to visitors more freely. Environmental stimuli were less controlled in occasional breeders, raising the debate about quantity versus quality of stimuli at a young age. Large-scale breeders declared to screen potential owners less intensely and time to advise them was limited. To the authors' knowledge, this is the first study that compares a large number of environmental factors between the different dog breeding categories., Competing Interests: Competing interests: None declared., (© British Veterinary Association 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Like humans, canine companions often find themselves in noisy environments, and are expected to respond to human speech despite potential distractors. Such environments pose particular problems for young children, who have limited linguistic knowledge. Here, we examined whether dogs show similar difficulties. We found that dogs prefer their name to a stress-matched foil in quiet conditions, despite hearing it spoken by a novel talker. They continued to prefer their name in the presence of multitalker human speech babble at signal-to-noise levels as low as 0 dB, when their name was the same intensity as the foil. This surpasses the performance of 1-year-old infants, who fail to prefer their name to a foil at 0 dB (Newman in Dev Psychol 41(2):352-362, 2005). Overall, we find better performance at name recognition in dogs that were trained to do tasks for humans, like service dogs, search-and-rescue dogs, and explosives detection dogs. These dogs were of several different breeds, and their tasks were widely different from one another. This suggests that their superior performance may be due to generally more training and better attention. In summary, these results demonstrate that dogs can recognize their name even in relatively difficult levels of multitalker babble, and that dogs who work with humans are especially adept at name recognition in comparison with companion dogs. Future studies will explore the effect of different types of background noise on word recognition in dogs.