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Let me sniff! Nosework induces positive judgment bias in pet dogs

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Let me sniff! Nosework induces positive judgment bias in pet dogs

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Abstract

When confronted with an ambiguous stimulus, an individual's perception of and behaviour towards the situation are affected by emotional states. In a new situation, positive emotional states lead to optimistic reactions; negative emotional states, to pessimistic reactions. This phenomenon is related to welfare and is well-studied in humans and other animals via the cognitive bias test. This test is often used in applied ethology, especially for captive animals, and assesses the emotional state of animals to evaluate their welfare. However, one species is often forgotten in that category of “captive animals”: domestic dogs. Pet dogs can be considered “captive” insofar as they cannot choose their daily activities; nor do they generally have the opportunity to express the natural behaviors necessary for their welfare – such as olfactory foraging behaviour. In this study, we tested the effect of an olfaction-based activity on pet dogs’ emotional states. Dogs were first given a cognitive bias test, then practiced a daily, specified activity for two weeks, and finally were given a cognitive bias test again. The activity conducted differed between the groups: dogs from the experimental group practiced nosework, and dogs from the control group practiced heelwork. Results show that the latency to approach the ambiguous stimulus declined significantly after treatment in the experimental group, whereas the latency did not change for dogs in the control group. We conclude that allowing dogs to spent more time using their olfaction through a regular nosework activity makes them more optimistic. By allowing dogs more “foraging” time, their welfare is improved. Applications for pet dogs in daily life are discussed.

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... The general procedure for this spatial judgement task is as follows: a positive location is paired with food (baited) and a negative location is paired with no reward (non-baited). The most common presentation used with domestic dogs utilises the placement of dog food bowls (e.g., Duranton and Horowitz 2019;Gruen et al. 2019;Kis et al. 2015;Mendl et al. 2010;Müller et al. 2012;Wells et al. 2017. However, see Burman et al. 2011 for a paradigm using coloured card, and Burani et al. 2022 using discrete corridors). ...
... If the dog is faster to approach the ambiguous bowl, it indicates a positive judgement bias (more "optimistic"), whereas a slower approach suggests a negative judgement bias (more "pessimistic"). This protocol has been used successfully in previous studies focussing on domestic dogs to investigate the effects of a range of affect manipulations, including different types of enrichment (Duranton and Horowitz 2019), behavioural, and pharmacological interventions (Karagiannis et al. 2015;Casey et al. 2021). However, studies within the canine literature investigating the reliability and repeatability of this measure are lacking. ...
... The focus of this study is assessing the effects of learning on the canine-adapted judgement bias task across multiple sessions. When measuring the impact of an intervention, some studies have utilised repeated measures before and after the intervention, with the judgement bias task being carried out on the same cohort multiple times (e.g., Karagiannis et al. 2015;Duranton and Horowitz 2019). Karagiannis et al. (2015) included a control group in their study looking at the effectiveness of a behavioural and fluoxetine intervention on dogs' behaviour using a repeated judgement bias task as a measure of affect. ...
Article
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Judgement bias paradigms are increasingly being used as a measure of affective state in dogs. Approach to an ambiguous stimulus is commonly used as a measure of affect, however, this may also be influenced by learning. This study directly measured the impact of learning on a commonly used judgement bias paradigm in the absence of an affective state manipulation. Dogs ( N = 15) were tested on a judgement bias task across five sessions. The dogs’ latency to approach a bowl placed in one of three ambiguous locations between non-baited (negative) and baited (positive) locations was measured. Results show that session number had a significant effect on the dogs’ latencies to reach the ambiguous bowl locations, with post-hoc tests revealing that dogs were significantly slower to approach the locations as the number of sessions increased. Session number also had a significant effect on the number of times the dogs did not approach the bowl within 30 s of being released, with the number of no approaches generally increasing across sessions. When dog identity was included as a fixed effect, a significant effect on latency to approach was found, suggesting that some dogs were consistently faster than others across sessions. To assess whether the paradigm produced repeatable results, Intraclass Correlation Coefficients were used. A low degree of reliability was found between latencies to approach each bowl position across sessions. This study demonstrates that dogs learned that the ambiguous locations were not rewarded with repeated exposures, and that this impacted their responses. We conclude that this judgement bias paradigm may require further consideration if applied across multiple exposures and that repeated results should be interpreted with caution as they are likely impacted by learning.
... Dogs have idiosyncratic exercise requirements to preserve optimal health physiologically and psychologically. Studies demonstrate that dogs that spent more time using their olfaction through regular nosework activity are more optimistic which increases their welfare [1]. Appropriate dog-walking activities are also essential for effective strategies to prevent for instance canine obesity [2] and assist social interactions and aid cognitive as well as behavioural development and wellbeing [1,3]. ...
... Studies demonstrate that dogs that spent more time using their olfaction through regular nosework activity are more optimistic which increases their welfare [1]. Appropriate dog-walking activities are also essential for effective strategies to prevent for instance canine obesity [2] and assist social interactions and aid cognitive as well as behavioural development and wellbeing [1,3]. Dog proprietorship however does not warrant that owners will on a regular basis exercise their dog(s) [4] and great cultural differences exist regarding the walking regiment. ...
... Insofar as pet dogs are not able to choose either their daily activities or the quality of their walks with respect to time, distance and cognitive input it is important to consider the opportunities offered by the owner to express natural behaviours necessary for the dogs' welfare. These include autonomous movement, initiative taking, to have choices for instance where and what to explore and to make decisions of what or whom to approach or to avoid [1,9]. ...
Article
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The approximate figure of pet dogs reported in Europe 2020 is 87.5 million. These dogs live mainly either in enclosed properties or their exercise takes place in form of a daily round of walks with their owner, frequently on a leash. The importance of regular exercise for dogs is well known and benefits to physiological and psychological well-being through off leash explorative behavior has been documented. Off leash walks benefit health and welfare because the dog’s individual natural gait, social transaction ability and exploration behavior are thereby supported. In this study the behavior of free-ranging (off-leash) pet dogs was assessed whilst walking in familiar and unfamiliar areas with their owner and not being signaled or called to. Data were collected to measure distance travelled and duration dogs spent away from their owner during the walks to determine and compare speed and movement patterns of dog and owner respectively. The roaming behavior of the dogs was measured via GPS. All dogs displayed individual speed and exploration patterns and covered significantly longer distances at significantly higher speed compared to their owners. The majority of dogs, however, remained within a radius of 150 m of their owner all the time. Therefore, while it is inevitable for dogs to be on a leash in some situations whilst sharing our urban environment, safe and enriched areas for off leash activities are strongly recommend to ensure pet dogs’ physiological and psychological welfare by being able to explore in their own speed and employing their individual movement patterns.
... Notwithstanding, non-verbal paradigms are the only available tool to assess judgement biases in animals, therefore various protocols have been developed and adapted for several animal species (e.g. rats Harding et al. 2004;Rygula et al. 2013Rygula et al. , 2015Hales et al. 2014Hales et al. , 2016, starlings (Matheson et al. 2008), bees (Bateson et al. 2011), sheep (Doyle et al. 2010;Verbeek et al. 2014b, a), macaques (Bethell et al. 2012), pigs (Douglas et al. 2012), horses (Hintze et al. 2018), calves (Neave et al. 2013)), including the domestic dog, Canis familiaris (Mendl et al. 2010a;Wells et al. 2017;Uccheddu et al. 2018; Barnard et al. 2018;Duranton and Horowitz 2019). Despite the large number of studies that have used JBTs to evaluate the welfare and the affective state in animals, doubts remain about its reliability: results are not always in line with predictions, with some studies even leading to null results or to opposite findings to those expected (Iigaya et al. 2016;Roelofs et al. 2016;Raoult et al. 2017). ...
... It is worth noting that other studies, whilst reporting an association between emotions and cognitive biases in dogs, presented methodological and statistical issues, such as a small sample size that makes more difficult to infer a general behavioural pattern (Karagiannis et al. 2015;Cockburn et al. 2018), the employment of only a single ambiguous trial, the outcome of which could be influenced by momentary distraction (Kis et al. 2015;Duranton and Horowitz 2019) and the use of a statistical approach that evaluates the dog's average response instead of single trial responses, thereby reducing variability in data (Mendl et al. 2010a;Willen et al. 2019;Vieira de Castro et al. 2020). ...
Article
Full-text available
The judgement bias test represents one of the most applied tools to evaluate animals’ optimistic/pessimistic attitude and to infer their emotional and welfare state accordingly. The judgement bias test (JBT) has been used several times with dogs (Canis familiaris), in most cases using a spatial test that evaluates the dog’s attitude towards a bowl placed in ambiguous positions (located between two unambiguous trained positions associated with opposite outcomes). Results are contrasting and methodological and statistical caveats emerged: dogs struggled to learn the association between unambiguous positions and their outcomes, they hardly discriminated between adjacent locations and they might be influenced by researchers. Therefore, we propose a novel paradigm, aimed at easing the learning process and at achieving more reliable measures. Improvements of the novel paradigm are the increased difference between payoffs of trained locations, the reduction of the number of trials and of their length and the removal of the potential influence of researchers. Results showed that 98% of dogs reached the learning criterion and that their learning appeared more stable: dogs behaved differently between the two trained stimuli and the variability of responses towards these stimuli was lower than the one towards ambiguous stimuli. Behavioural analyses confirmed that dogs fully learned outcomes associated with trained stimuli and that they were hesitant towards ambiguous stimuli. Furthermore, dogs managed to successfully discriminate between each pair of adjacent locations. These results suggest that this protocol is a promising tool to assess judgement biases in dogs and to evaluate their affective state.
... Meer algemeen kan het helpen om een hond meer zelfvertrouwen te geven door hem meer successen te laten beleven in oefeningen rond probleemoplossing, wat ook het probleemoplossend vermogen bij honden verhoogt (Duranton & Horowitz, 2019). Een belangrijke voorwaarde voor verbeterd zelfvertrouwen en probleemoplossend vermogen is een goede relatie tussen de hond en de eigenaar (Horn et al., 2013;Topál et al., 1997). ...
... Ook het blootstellen van een hond aan allerlei nieuwe stimuli -liefst op jonge leeftijd -en positieve ervaringen bij deze stimuli kan het zelfvertrouwen bij een hond vergroten (Appleby & Pluijmakers, 2003, 2016a Een belangrijke manier om zelfvertrouwen en probleemoplossend vermogen te kunnen versterken is via bijvoorbeeld speuractiviteiten. Zo toont onderzoek aan dat verborgen voedsel vinden het optimisme verhoogt bij honden (Duranton & Horowitz, 2019) wat kan wijzen op hoger zelfvertrouwen en meer positieve emotie (Karagiannis et al., 2015). De reden hiervoor ligt wellicht in het quasi geheel zelfstandige aspect van probleemoplossend gedrag binnen speuren evenals in het feit dat de hond keuze (i.e. ...
Thesis
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In dit werk wordt ingegaan op scheidingsgerelateerd(e) probleemgedrag (SGP) of -gedragingen (SGP’s) bij honden. Ter vergemakkelijking worden doorheen dit werk vanaf nu de afkortingen SGP en SGP’s gebruikt. Op basis van wetenschappelijke literatuur en literatuur gericht aan hondeneigenaren wordt een overzicht gegeven van de huidige inzichten rond SGP, inclusief aanvullingen en bedenkingen bij huidige gangbare kennis over dit thema in de theorie en in de praktijk. Behalve van (wetenschappelijke) literatuur maak ik gebruik van praktijkkennis en -inzichten bij hondengedragsdeskundigen. Immers, het belang van “bottom-up” kennis die vertrekt vanuit de (veelal jarenlange) praktijkervaring van wie (veelal dagelijks) in de praktijk staat, wordt steeds vaker benadrukt, ook vanuit wetenschappelijke hoek. Het includeren van kennis die “leeft” onder experts – maar ook onder eigenaars die vanuit hun ervaring de gedragsproblemen met hun hond vaak goed kunnen beschrijven – kan beschouwd worden als een vorm van burgerwetenschap (“citizen science”) en kan onderzoekers helpen in de beschrijving van fenomenen die ze nadien willen verklaren en/of – in dit geval – waarvoor ze aangepaste behandelprotocollen en gerichte informatie willen verspreiden bij het juiste publiek. Binnen dit eindwerk maak ik bewust gebruik van deze “levende kennis” omdat zij kan bijdragen aan een beter begrip van onduidelijkheden over het fenomeen SGP. Daarnaast kan deze kennis informatie geven over zaken die (nog) niet wetenschappelijk bestudeerd zijn en richting geven aan pistes voor toekomstig onderzoek.
... Nonetheless, identifying and supporting regular opportunities for working dogs to exercise agency and increase behavioral diversity in both environmental and social contexts is an opportunity for future studies. One activity that has been shown to induce positive judgement bias in dogs, is nosework (150). Letting dogs engage in olfactory-based sniffing activities resulted in them exercising autonomy and agency, resulting in increased optimism (150). ...
... One activity that has been shown to induce positive judgement bias in dogs, is nosework (150). Letting dogs engage in olfactory-based sniffing activities resulted in them exercising autonomy and agency, resulting in increased optimism (150). ...
Article
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Working dogs are prevalent throughout our societies, assisting people in diverse contexts, from explosives detection and livestock herding, to therapy partners. Our scientific exploration and understanding of animal welfare have grown dramatically over the last decade. As community attitudes toward the use of animals continue to change, applying this new knowledge of welfare to improve the everyday lives of working dogs will underpin the sustainability of working with dogs in these roles. The aim of this report was to consider the scientific studies of working dogs from the last decade (2011–2021) in relation to modern ethics, human interaction, and the five domains of animal welfare: nutrition, environment, behavioral interaction, physical health, and mental state. Using this framework, we were able to analyze the concept and contribution of working dog welfare science. Noting some key advances across the full working dog life cycle, we identify future directions and opportunities for interdisciplinary research to optimize dog welfare. Prioritizing animal welfare in research and practice will be critical to assure the ongoing relationship between dogs and people as co-workers.
... The effect of performing complex, species-specific behavior on animal emotion has received comparatively little attention, despite suggestive evidence that it improves mood in humans [1-5, 8, 34, 35]. To date, only two studies have directly examined whether animals show more positive affect after carrying out complex species-specific behaviors [36,37]. These studies have found mixed results. ...
... However, this may have been an artifact of the study design; dogs were interrupted during their search of the maze, which could have promoted a negative affective state (because they were prevented from eating the rest of the food). In another study, when dogs practiced nosework (searching for food using olfactory cues, a species-specific behavior), they became more optimistic, and dogs who practiced heelwork (walking behind their owner) did not change their affective state [36]. Although these results raise the possibility that complex, species-specific behaviors can improve animal affective states, the nosework group were trained to search for food, and the heelwork group were trained not to move freely. ...
Article
Are complex, species-specific behaviors in animals reinforced by material reward alone or do they also induce positive emotions? Many adaptive human behaviors are intrinsically motivated: they not only improve our material outcomes, but improve our affect as well [1-8]. Work to date on animal optimism, as an indicator of positive affect, has generally focused on how animals react to change in their circumstances, such as when their environment is enriched [9-14] or they are manipulated by humans [15-23], rather than whether complex actions improve emotional state. Here, we show that wild New Caledonian crows are optimistic after tool use, a complex, species-specific behavior. We further demonstrate that this finding cannot be explained by the crows needing to put more effort into gaining food. Our findings therefore raise the possibility that intrinsic motivation (enjoyment) may be a fundamental proximate cause in the evolution of tool use and other complex behaviors. VIDEO ABSTRACT.
... If a dog does not have these natural tendencies, with training and a lot of effort, they may be able to achieve the basic skills to function as a search-and-rescue dog, but a dog that has natural tendencies for these skills will reduce the necessary training time and increase the likelihood of success. Additionally, from a welfare perspective, expressing natural behaviors is thought to be intrinsically rewarding to a dog (148). In order to maximize the success of working dogs and thoughtfully place each dog in a role that is suited to that dog's physical abilities and temperament, the phenotype associated with each career path needs to be clearly defined and tests validated to predict performance. ...
Article
Full-text available
Dogs perform a variety of integral roles in our society, engaging in work ranging from assistance (e.g., service dogs, guide dogs) and therapy to detection (e.g., search-and-rescue dogs, explosive detection dogs) and protection (e.g., military and law enforcement dogs). However, success in these roles, which requires dogs to meet challenging behavioral criteria and to undergo extensive training, is far from guaranteed. Therefore, enhancing the selection process is critical for the effectiveness and efficiency of working dog programs and has the potential to optimize how resources are invested in these programs, increase the number of available working dogs, and improve working dog welfare. In this paper, we review two main approaches for achieving this goal: (1) developing selection tests and criteria that can efficiently and effectively identify ideal candidates from the overall pool of candidate dogs, and (2) developing approaches to enhance performance, both at the individual and population level, via improvements in rearing, training, and breeding. We summarize key findings from the empirical literature regarding best practices for assessing, selecting, and improving working dogs, and conclude with future steps and recommendations for working dog organizations, breeders, trainers, and researchers.
... Last, it is important to highlight the potential impact detection training itself may have on the welfare of the dogs. Recent research has suggested that scent training can induce a positive judgement bias in dogs [34]. Given that the population of dogs participating in this study were in a training to adopt program, training and procedures that improve the welfare of animals is an important consideration. ...
Article
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Despite dogs’ widespread use as detection systems, little is known about how dogs generalize to variations of an odorant’s concentration. Further, it is unclear whether dogs can be trained to discriminate between similar concentration variations of an odorant. Four dogs were trained to an odorant (0.01 air dilution of isoamyl acetate) in an air-dilution olfactometer, and we assessed spontaneous generalization to a range of concentrations lower than the training stimulus (Generalization Test 1). Dogs generalized to odors within a 10-fold range of the training odorant. Next, we conducted discrimination training to suppress responses to concentrations lower than a concentration dogs showed initial responding towards in Generalization Test 1 (0.0025 air dilution). Dogs successfully discriminated between 0.0025 and 0.01, exceeding 90% accuracy. However, when a second generalization test was conducted (Generalization Test 2), responding at the 0.0025 concentration immediately recovered and was no different than in Generalization Test 1. Dogs were then tested in another generalization test (Compound Discrimination and Generalization) in which generalization probes were embedded within discrimination trials, and dogs showed suppression of responding to the 0.0025 concentration and lower concentrations in this preparation. These data suggest dogs show limited spontaneous generalization across odor concentration and that dogs can be trained to discriminate between similar concentrations of the same odorant. Stimulus control, however, may depend on the negative stimulus, suggesting olfactory concentration generalization may depend on relative stimulus control. These results highlight the importance of considering odor concentration as a dimension for generalization in canine olfactory research.
... Handlers, however, may potentially negatively impact working performance by unintentionally cuing the dog (29)(30)(31)(32). A classic example of unintentional postural and facial cues is the famous "Clever Hans" example, in which a horse's incredible skills was later demonstrated to be remarkably controlled by unintentional cues (33). ...
Article
Full-text available
Detection dogs are commonly trained and tested under conditions in which the handler or the evaluator knows the true presence or absence of a target odor. Previous research has demonstrated that when handlers are deceived and led to believe that a target odor is present, more false alerts occur. However, many detection teams operate under unknown conditions, and it remains unclear how handler knowledge (or lack thereof) of odor presence/absence influences the dog's behavior. The aim of this study was to evaluate if knowing the number of hides placed influenced detection dog performance in an applied search environment. Professional (n = 20) and sport (n = 39) detection handler-dog teams were asked to search three separate areas (area 1 had one hide, area 2 had one hide, area 3 was blank). Handlers in the Unknown Group were not told any information on the number of hides whereas the Known Group were told there was a total of two hides in the three areas. The sport Unknown Group spent a longer duration (69.04 s) searching in area 3 compared to the sport Known Group (p = 0.004). Further, sport dogs in the Unknown group looked back to the handler more frequently. When a miss did occur, dogs of both sport and professional handlers showed an increase interest in the location of the target odor compared to a comparison location. Critically, however, there was no difference in false alerts between the Known Group and Unknown Group for sport or professional handlers. In a second experiment, fourteen professional, and thirty-nine sport teams from Experiment 1 conducted an additional search double-blind and an additional search single-blind. Both sport and professional-handler dog teams had statistically similar accuracy rate under single and double blind conditions. Overall, when handlers knew the number of hides, it led to significant changes in search behavior of the detection team but did not influence the overall false alert rates.
... Nose-or scent-work for horses consists of placing an odor in/at a designated place in the horse's environment either indoor or outdoor, and subsequently allowing the horse to sniff out the odor, which then elicits a reward (Draaisma, 2021). Despite the increasing popularity of nose work in horse training, however, there is no scientific background for its applicability or for selecting suitable odors, hence these exercises are mainly based on knowledge from dogs (Duranton and Horowitz, 2019;DeGreeff et al., 2020;Draaisma, 2021). Some trainers thus use knowledge of olfaction in their daily handling and training of horses, without any scientific information of its efficacy and potential effect of individual variation. ...
Article
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In spite of a highly developed olfactory apparatus of horses, implying a high adaptive value, research on equine olfaction is sparse. Our limited knowledge on equine olfaction poses a risk that horse behavior does not match human expectations, as horses might react fearful when exposed to certain odors, which humans do not consider as frightening. The benefit of acquiring more knowledge of equine olfaction is therefore twofold; (1) it can aid the understanding of horse behavior and hence reduce the risk of dangerous situations, and (2) there may be unexplored potential of using odors in several practical situations where humans interact with horses. This study investigated behavior and olfactory sensitivity of 35 Icelandic horses who were presented with four odors: peppermint, orange, lavender and cedar wood in a Habituation/Dishabituation paradigm. The response variables were sniffing duration per presentation and behavioral reaction (licking, biting, snorting, and backing), and data were analyzed for potential effects of age, sex and pregnancy. Results showed that habituation occurred between successive odor presentations (1st vs. 2nd and 2nd vs. 3rd presentations: P < 0.001), and dishabituation occurred when a new odor was presented (1st vs. 3rd presentations: P < 0.001). Horses were thus able to detect and distinguish between all four odors, but expressed significantly longer sniffing duration when exposed to peppermint (peppermint vs. orange, lavender and cedar wood: P < 0.001). More horses expressed licking when presented to peppermint compared to cedar wood and lavender ( P = 0.0068). Pregnant mares sniffed odors less than non-pregnant mares ( P = 0.030), young horses (age 0-5 years) sniffed cedar wood for longer than old horses ( P = 0.030), whereas sex had no effect ( P > 0.050). The results show that horses’ odor exploration behavior and interest in odors varies with age and pregnancy and that horses naïve to the taste of a substrate, may be able to link smell with taste, which has not been described before. These results can aid our understanding of horses’ behavioral reactions to odors, and in the future, it may be possible to relate these to the physiology and health of horses.
... Recent literature shows that dogs distinguish other individuals, their sex and reproductive state through their smell [5,6] and perceive social information conveyed by odors, like conspecific and human emotions [7]. The exposure to olfactory emotional signals [8] and to different types of essential oils [9,10] influences dog behavior and, as recently reported by Duranton and Horowitz [11], a regular olfactory-based activity (i.e., nosework) improves dogs' affective state and welfare. Furthermore, a relationship between olfaction and cognition has been described in dogs. ...
Article
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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.
... Thus, future research should sample dog populations with more standardized training backgrounds to isolate the specific components of training that support social evaluation. It is possible that various types of training may support the development of different types of cognition [see Duranton and Horowitz (2019) for an example of specific training practices impacting dogs' judgment biases], and thus that dogs trained for different tasks or using different techniques may display different patterns of behavior in social evaluation tasks. ...
Article
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Humans evaluate other agents’ behavior on a variety of different dimensions, including morally, from a very early age. For example, human infants as young as 6-months old prefer prosocial over antisocial others and demonstrate negative evaluations of antisocial others in a variety of paradigms (Hamlin et al. in Nature 450(7169):557, 2007; Dev Sci 13(6):923–929, 2010; Proc Natl Acad Sci 108(50):19931–19936, 2011). While these tendencies are well documented in the human species, less is known about whether similar preference emerge in non-human animals. Here, we explore this question by testing prosocial preferences in one non-human species: the domestic dog (Canis lupus familiaris). Given the ubiquity of dog–human social interactions, it is possible that dogs display human-like social evaluation tendencies. Unfortunately, prior research examining social evaluation in dogs has produced mixed results. To assess whether differences in methodology or training differences account for these contrasting results, we tested two samples of dogs with different training histories on an identical social evaluation task. Trained agility dogs approached a prosocial actor significantly more often than an antisocial actor, while untrained pet dogs showed no preference for either actor. These differences across dogs with different training histories suggest that while dogs may demonstrate preferences for prosocial others in some contexts, their social evaluation abilities are less flexible and less robust compared to those of humans.
... Some studies in this area, whilst reporting a significant association between emotions and cognitive biases in dogs, have reported methodological and statistical issues, including a small sample size that makes it hard to infer a general behavioural pattern [37,38], the employment of a single ambiguous trial, the outcome of which could be influenced by momentary distraction [39,40] and the use of a statistical approach that evaluates the average dog's response instead of single trial responses, thereby reducing variability in the data [27,31,41]. Averaged measures are inevitably less accurate since, during the test, trials are repeated for each dog and for each type of cue and the number of repetitions is not consistent among cues (more trials for each trained cue, less trials for each ambiguous cue to minimize a potential learning effect). ...
Article
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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.
... Dogs' ability to engage in exploratory and sniffing behaviour is reduced when on lead compared to off lead during walks [38] and thus it is likely that the increased use of leads during lockdown reduced the opportunities for dogs to investigate their olfactory environment. This is a concern, as dogs have highly developed olfactory ability [39] and scent is a key mode of communication for dogs [40], with olfactory enrichment shown to be beneficial to dogs in a rescue shelter [41] and to improve dogs' mood through cognitive stimulation [42]. Furthermore, the effects of changes in walking could lead to dogs experiencing frustration in the short-term [43] and may potentially increase the risk of over-enthusiastic interactions when dog-dog interactions take place again as restrictions are eased. ...
Article
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Initial COVID-19 lockdown restrictions in the United Kingdom (23rd March–12th May 2020) prompted lifestyle changes for many people. We explored the impact of this lockdown phase on pet dogs using an online survey completed by 6004 dog owners, who provided information including dog management data for the 7 days prior to survey completion (4th–12th May 2020), and for February 2020 (pre-lockdown). We explored associations between potential predictors and four outcomes relating to changes pre-/during lockdown (reduction in number and duration of walks; increased frequency of play/training, and provision of toys). Most owners (79.5%) reported their dog’s routine had changed compared to pre-lockdown. There was a four-fold increase in the proportion not left alone for >5 min on any day during a weekly period (14.6% pre-lockdown, 58.0% during lockdown), with the proportion being left for ≥3 h at a time decreasing from 48.5% to 5.4%. Dogs were walked less often and for less time daily during lockdown, with factors related to the dog, owner, household, and home location associated with changes to walking practices. Many dogs had more play/training sessions and were given toys more frequently during lockdown. Decreased walk duration was associated with increased odds of play/training opportunities and toy provision. These changes to dog management have the potential for immediate and longer-term welfare problems.
... 60 Regular walking may be a pet dog's only opportunity to engage in vital canine behaviours such as sniffing, social interactions and scent marking. 12,62 Lead pulling could reduce access to these, triggering other undesirable behaviours 61,63 -digging, destruction, excessive vocalisation and escape attempts. Furthermore, if lead pulling causes, or is a sequela of, acute or chronic stress and accompanying hyperarousal, dogs that pull might be less likely to engage in species-specific behaviours when walking. ...
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Veterinary professionals (VPs) are often the first source of advice for clients struggling with their dog’s behaviour, and pulling on the lead is a common-place undesirable behaviour VPs will encounter regularly in practice. Excluding bites, being pulled over while walking on a lead is the leading cause of non-fatal dog-related injuries in the UK. This narrative review investigates lead pulling as a welfare concern in pet dogs, highlighting aspects of the literature of particular interest to VPs. Lead pulling could negatively affect walk quality, frequency and duration,causing weight gain, while decreased environmental enrichment could trigger other undesirable behaviours. Aversive equipment to prevent lead pulling can cause pain, distress and injury, but even equipment considered humane can have welfare consequences. Punitive training methods could cause dogs stress, fear and anxiety and trigger aggressive behaviour. While these lead pulling outcomes are welfare concerns in themselves, they could also weaken dog–owner attachment, a risk factor in pet dog relinquishment.Given lead pulling could affect the welfare of patients in a VPs care, clinical implications and opportunities for client education are outlined. Educating clients on humane prevention and modification of lead pulling could make walks easier, safer and more enjoyable, with positive outcomes for clients,canine welfare and the practice.
... Despite the primacy of olfaction for dogs, there is still a dearth of research investigating domestic dogs' experience of odors in the 6 anthropogenic environment (Horowitz & Franks, 2019). More attention to olfaction may improve dogs' welfare (Duranton & Horowitz, 2019); understanding the role of olfaction in dogs' experience may, too, improve the relationship between people and their dogs. ...
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... There is also a focus on assessing animals' expression of behaviors that may be momentary indicators of positive or negative affect. Among the indicators of positive moments, observers often look for behaviors that indicate that animals are able to express control/agency [15,16,[57][58][59], solve challenges [60][61][62], investigate [63,64] and express preferences [65][66][67][68]. In regard to negative moments, we often look for indicators of anxiety [69,70], fear [68], pain [69,[71][72][73][74] or boredom [75][76][77]. ...
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An emphasis on ensuring animal welfare is growing in zoo and aquarium associations around the globe. This has led to a focus on measures of welfare outcomes for individual animals. Observations and interpretations of behavior are the most widely used outcome-based measures of animal welfare. They commonly serve as a diagnostic tool from which practitioners make animal welfare decisions and suggest treatments, yet errors in data collection and interpretation can lead to the potential for misdiagnosis. We describe the perils of incorrect welfare diagnoses and common mistakes in applying behavior-based tools. The missteps that can be made in behavioral assessment include mismatches between definitions of animal welfare and collected data, lack of alternative explanations, faulty logic, behavior interpreted out of context, murky assumptions, lack of behavior definitions, and poor justification for assigning a welfare value to a specific behavior. Misdiagnosing the welfare state of an animal has negative consequences. These include continued poor welfare states, inappropriate use of resources, lack of understanding of welfare mechanisms and the perpetuation of the previously mentioned faulty logic throughout the wider scientific community. We provide recommendations for assessing behavior-based welfare tools, and guidance for those developing tools and interpreting data.
... This was further emphasized by participants in their open-ended item responses, e.g., "Certainly the public perception via the media show them as happy and enjoying the work they do." There is evidence to support that allowing companion dogs to engage in nosework (sniffing things) makes them more "optimistic" on a cognitive bias task, indicating that sniffing is good for their welfare (Duranton & Horowitz, 2019), but there is no comparable study to date for DDDs. The themes "Mutually beneficial relationship" and "Owners emotional benefit" observed in relation to assistance dogs (Gibson & Oliva, 2021) were not endorsed in relation to DDDs, which might be explained by the fact people see these dogs' work as offering a community benefit rather than a direct benefit to their owner. ...
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... The sense of smell in dogs is not only a highly developed sense, but also plays a huge role in the animal's welfare. The smell can also be combined with the individual preferences of the animal [62], which in turn can be modulated by previous experiences. The ability of odors to evoke past memories has been shown in humans, as well as in dogs [63][64][65]. ...
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In spite of the highly developed olfactory apparatus of horses, implying a high adaptive value, research on equine olfaction is sparse. Our limited knowledge poses a risk that horse behaviour does not match human expectations. The benefit of acquiring more knowledge of equine olfaction is therefore twofold; 1) it can aid the understanding of horse behaviour and hence reduce the risk of dangerous situations, and 2) there may be unexploited potential of using odours in several practical situations where humans interact with horses. This study investigated olfactory abilities of, 35 Icelandic, horses who were presented to four odours: peppermint, orange, lavender and cedarwood. The response variables were sniffing duration per presentation and behavioural reaction (licking, biting, snorting, and backing). Results showed horses were able to detect and distinguish between all four odours and showed increased interest (significantly longer sniffing duration) for peppermint. More horses expressed licking behaviour when presented to peppermint compared to cedarwood and lavender. Young horses sniffed cedarwood for longer than old horses, and pregnant mares sniffed lavender less than non-pregnant mares. In conclusion, the test paradigm seemed meaningful for horses, and olfactory interest of horses varied with age and gestational status but not sex.
Chapter
Our relationship with dogs runs thousands of years deep. Today, we might know dogs intimately as members of our human family, but we can also know and consider dogs on their own terms, as members of Canis familiaris , with a unique evolutionary history and species‐specific characteristics and needs. This chapter is a resource for all types of dog knowers and caretakers. It relies heavily on empirical research to anchor readers in the foundations of canine behavior—such as dog behavioral development, normal dog behavior, factors influencing behavior, and relationships with people—and considers how these topics affect dogs of all ages and backgrounds who find themselves in the shelter environment.
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It is widely acknowledged that environmental enrichment can improve animals’ welfare and emotional state. This study used cognitive bias and response to a novel object to assess the effect of enriched housing on emotional state in sheep. Eighteen sheep were trained to discriminate between high-quality and low-quality reward locations using a go/go task. Sheep were allocated to a housing treatment (enriched or standard) for three weeks. Judgment bias tests were conducted using three ambiguous, unrewarded locations across three days, followed by assessing responses to a novel object. Effects of anxiety levels shown in training on responses to ambiguous locations and to the presence of a novel object were assessed. Enriched-housed sheep tended to have shorter latencies to approach ambiguous positions than standard-housed sheep (P = 0.08), particularly to the near and middle locations. Sheep from standard housing tended to have shorter latencies to approach food with the novel object present than sheep from enriched hosing (P = 0.06). This study shows that enrichment can affect emotional state and that go/go tasks can be successful in sheep and should be considered in future studies of emotional state.
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To perform quick assessments, welfare practitioners may focus on specific behavioral indicators of welfare, which can lead to challenges in interpretation. Anticipatory behavior has been suggested as a potentially graded indicator of well-being in animals. However, there are difficulties in assessing variations in this class of behavior quantitatively. Here, we propose an analytical approach for identifying and comparing the intensity of anticipatory behavior across different conditions. We evaluated the changes in the behavior of a sea lion at the San Francisco Zoo before and after daily training sessions, the start time of which had differing degrees of predictability. We show that anticipatory behavior is a complex suite of behaviors that can show multi-directional changes prior to an anticipated event. Additionally, we show that the methods utilized here can distinguish among differing intensities of anticipation directed toward daily husbandry events. We suggest that this approach may be broadly applicable for applying measures of anticipatory behavior as a graded welfare indicator.
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Material produzido pelo grupo de trabalho Psicovida com o objetivo de promover qualidade de vida em tempos de pandemia para idosos e cuidadores.
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Horses are commonly trained using negative reinforcement. However, a growing body of scientific evidence supports positive reinforcement as an efficient training method for horses. In this study we investigated the effects of adding a small but regular amount of positive reinforcement training to horses trained with negative reinforcement. A total of 36 privately owned horses not previously trained with positive reinforcement were divided into a training (N=17) and a control (N=19) group. The owners in the training group were asked to follow a training plan based on positive reinforcement for eight to nine weeks, in addition to their normal negative reinforcement training. The control horses continued with their usual negative reinforcement training. All horses were subjected to behavioural tests before and after the training period: a motionless human test to assess contact-seeking behaviour and a cognitive bias test to assess emotional state. Mane hair samples were obtained from all horses at the start and at the end of the training period to analyse hair cortisol concentrations as an expression of long-term stress. In addition, all owners filled out a questionnaire about their perceived relationship with their horses before and after the training period. We found that horses in the training group engaged in more physical contact (P=0.050) with an unfamiliar person after the training period compared to before. The training group also tended to improve their owner-assessed relationship score (P=0.072). They did not, however, show changes in their emotional state as assessed by the cognitive bias test (P>0.1). Furthermore, we found no difference between the training and control groups in terms of hair cortisol concentrations. We conclude that a small but regular addition of positive reinforcement training can increase horses’ contact-seeking behaviour towards humans but is not enough to improve their emotional state or long-term stress levels.
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During two retreats in 2017 and 2020, a group of international scientists convened to explore the Human-Animal Bond. The meetings, hosted by the Wallis Annenberg PetSpace Leadership Institute, took a broad view of the human-dog relationship and how interactions between the two may benefit us medically, psychologically or through their service as working dogs (e.g. guide dogs, explosive detection, search and rescue, cancer detection). This Frontiers’ Special Topic has collated the presentations into a broad collection of 14 theoretical and review papers summarizing the latest research and practice in the historical development of our deepening bond with dogs, the physiological and psychological changes that occur during human-dog interactions (to both humans and dogs) as well as the selection, training and welfare of companion animals and working dogs. The overarching goals of this collection are to contribute to the current standard of understanding of human-animal interaction, suggest future directions in applied research, and to consider the interdisciplinary societal implications of the findings.
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Treves et al. (2019) make a convincing case that conservation efforts need to go beyond an anthropocentric worldview. Implementing that vision, however, will require human advocates to represent nonhuman interests. Where will the knowledge of those interests come from? How can humans know what is in the best interest of another animal, a plant, or an ecosystem? We discuss how the values embedded in current scientific practices may be ill-suited to representing nonhuman interests and we offer some ideas for correcting these shortcomings.
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Introduction Enrichment strategies that are tailored to a dog’s individual needs and physical condition make an important contribution to improving its quality of life. Brachycephalic dogs are often subject to a variety of breed-related health problems so their well-being may be severely compromised and their physical capacities limited. One possible form of enrichment is nose work but there are hardly any scientific studies on whether the specific anatomy of brachycephalic dogs impair the animals' sense of smell. We have addressed whether the reaction to smell presentation (food in a sniffing carpet) and the subsequent search behaviour differ between dogs of a brachycephalic (French Bulldog) and a mesocephalic (Parson Russel Terrier) breed. Materials and methods Dry food was hidden in an object (a sniffing carpet) unknown to the dogs. Two identical sniffing carpets, only one of which was equipped with food (horse meat pellets), were presented in a test room to six French Bulldogs and six Parson Russel Terriers. The behaviour of each dog was video-recorded and analysed. Results The dogs' response to the hidden odour showed no breed-specific differences, suggesting that all dogs were able to sense the smell of the hidden food. However, the type and duration of the dogs‘ search behaviour at the sniffing carpet did show breed-specific differences. Conclusions Nose search games are also suitable for dogs with a shortened nose, such as French bulldogs, and can be recommended as an enrichment measure for this type of dog.
Chapter
The value of the canine nose is well-documented, and working dogs are being utilized for their olfactory skills in an increasing number of fields. Not only are dogs used by police, security, and the military, but they are also now used in forensic science, in medical detection of disease, in calculating population trends of endangered species and eradicating invasive species in protected environments, and in identifying infestations and chemical contaminants. Edited and contributed to by eminent scholars, Canine Olfaction Science and Law: Advances in Forensic Science, Medicine, Conservation, and Environmental Remediation takes a systematic scientific approach to canine olfaction. It includes work from scientists working in pure and applied disciplines, trainers and handlers who have trained and deployed detection dogs, and lawyers who have evaluated evidence produced with the aid of detection and scent identification dogs. The book is divided into six sections covering The anatomy, genetics, neurology, and evolution of canine olfaction as well as diseases affecting it The chemistry and aerodynamics of odors Behavior, learning, and training Uses of canine olfaction in forensics and law Uses in conservation and remediation Uses in detection of diseases and medical conditions The various contributors describe cutting edge research, some conclusions of which are the subject of vigorous debates between various laboratories and researchers. The editors have added cross-references so that readers can consider the different perspectives that are currently being advanced and understand where consensus is being built and where more research needs to be done. A useful practical reference, Canine Olfaction Science and Law provides a wealth of information beneficial to a wide range of disciplines. It aids trainers and handlers of detection dogs as well as various professionals in healthcare, law enforcement, forensic science, and environmental conservation to gain a better understanding of the remarkable power of the canine nose while encouraging further advances in applications.