How good is this food? A study on dogs' emotional responses to a potentially pleasant event using infrared thermography

Why do dogs wag their tails?

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

Non-invasive assessment of positive affective state using infra-red thermography in rats

With recent increased focus on positive welfare in animal welfare science, there is demand for objective positive welfare indicators. It is unclear whether changes in body surface temperature can be used to non-invasively identify and quantify positive states in mammals. We recorded continuous measurements of tail surface temperature using infra-red thermography (IRT) and concurrent behavioural observations in male and female Wistar rats (Rattus norvegicus). If tail surface temperature can differentiate between positive and negative experiences, we expect a qualitatively different response compared to negative experiences. Three groups of rats were presented with increasing magnitudes of food rewards (neutral/none, one and three rewards). The rats were placed in an arena to which they were habituated and filmed for 30 s before and 30 min after exposure to different rewards. Tail temperature initially decreased from the pre-reward baseline and subsequently returned towards baseline temperature. The overall pattern of the change was the same as for rats subjected to negative stimuli in previous studies. Nevertheless, dynamic changes in tail temperature, specifically the rate of recovery and the behavioural response (exploration), differed between neutral and rewarded rats but failed to distinguish reward magnitude. Sex differences were found in both thermal and behavioural responses, unrelated to reward magnitudes. Female rats exhibited a greater initial response with a slower recovery than male rats, emphasising the value of using of both sexes in animal welfare research. This study improves our understanding of the effects of positive emotions induced by food reward on peripheral body temperature and behaviour.

Village dogs match pet dogs in reading human facial expressions

Most studies on dogs' cognitive skills in understanding human communication have been conducted on pet dogs, making them a role model for the species. However, pet dogs are just a minor and particular sample of the total dog world population, which would instead be better represented by free-ranging dogs. Since free-ranging dogs are still facing the selective forces of the domestication process, they indeed represent an important study subject to investigate the effect that such a process has had on dogs' behavior and cognition. Despite only a few studies on free-ranging dogs (specifically village dogs) having been conducted so far, the results are intriguing. In fact, village dogs seem to place a high value on social contact with humans and understand some aspects of humans' communication. In this study we aimed to investigate village dogs' ability in understanding a subtle human communicative cue: human facial expressions, and compared them with pet dogs, who have already provided evidence of this social skill. We tested whether subjects were able to distinguish between neutral, happy, and angry human facial expressions in a test mimicking a potential real-life situation, where the experimenter repeatedly performed one facial expression while eating some food, and ultimately dropped it on the ground. We found evidence that village dogs, as well as pet dogs, could distinguish between subtle human communicative cues, since they performed a higher frequency of aversive gazes (looking away) in the angry condition than in the happy condition. However, we did not find other behavioral effects of the different conditions, likely due to the low intensity of the emotional expression performed. We suggest that village dogs' ability in distinguishing between human facial expressions could provide them with an advantage in surviving in a human-dominated environment.

Body surface temperature of rats reveals both magnitude and sex differences in the acute stress response

Understanding how biological markers of stress relate to stressor magnitude is much needed and can be used in welfare assessment. Changes in body surface temperature can be measured using infrared thermography (IRT) as a marker of a physiological response to acute stress. While an avian study has shown that changes in body surface temperature can reflect the intensity of acute stress, little is known about surface temperature responses to stressors of different magnitudes and its sex-specificity in mammals, and how they correlate with hormonal and behavioural responses. We used IRT to collect continuous surface temperature measurements of tail and eye of adult male and female rats (Rattus norvegicus), for 30 minutes after exposure to one of three stressors (small cage, encircling handling or rodent restraint cone) for one minute, and cross-validated the thermal response with plasma corticosterone (CORT) and behavioural assessment. To obtain individual baseline temperatures and thermal responses to stress, rats were imaged in a test arena (to which they were habituated) for 30 seconds before and 30 minutes after being exposed to the stressor. In response to the three stressors, tail temperature initially decreased and then recovered to, or overshot the baseline temperature. Tail temperature dynamics differed between stressors; being restrained in the small cage was associated with the smallest drop in temperature, in male rats, and the fastest thermal recovery, in both sexes. Increases in eye temperature only distinguished between stressors early in the response and only in females. The post stressor increase in eye temperature was greater in the right eye of males and the left eye of females. In both sexes encircling may have been associated with the fastest increase in CORT. These results were in line with observed behavioural changes, with greater movement in rats exposed to the small cage and higher immobility after encircling. The female tail and eye temperature, as well as the CORT concentrations did not return to pre-stressor levels in the observation period, in conjunction with the greater occurrence of escape-related behaviours in female rats. These results suggest that female rats are more vulnerable to acute restraint stress compared to male rats and emphasise the importance of using both sexes in future investigations of stressor magnitude. This study demonstrates that acute stress induced changes in mammalian surface temperature measured with IRT relate to the magnitude of restraint stress, indicate sex differences and correlate with hormonal and behavioural responses. Thus, IRT has the potential to become a non-invasive method of continuous welfare assessment in unrestrained mammals.

The Power of Discourse: Associations between Trainers' Speech and the Responses of Socialized Wolves and Dogs to Training

In a previous study, we found that Positive Reinforcement Training reduced cortisol of wolves and dogs; however, this effect varied across trainer-animal dyads. Here we investigate whether and how the trainers' use of speech may contribute to this effect. Dogs' great interest in high-pitched, intense speech (also known as Dog Directed Speech) has already been reported, but whether and how wolves respond similarly/differently to voice characteristics has never been studied before. We analyzed 270 training sessions, conducted by five trainers, with nine mixed-breed dogs and nine wolves, all human-socialized. Through Generalized Linear Mixed Models, we analyzed the effects of (a) three speech categories (nice, neutral, reprehensive) and laugh; and (b) acoustic characteristics of trainers' voices on animals' responses (correct responses, latency, orientation, time at less than 1 m, non-training behaviors, tail position/movements, cortisol variation). In both subspecies, tail wagging occurred more often in sessions with longer durations of nice speech, and less often in sessions with reprehensive speech. For dogs, the duration of reprehensive speech within a session was also negatively related to correct responses. For wolves, retreat time was associated with more reprehensive speech, whereas duration of nice speech was positively associated with time spent within one meter from the trainer. In addition, most dog behavioral responses were associated with higher average intonations within sessions, while wolf responses were correlated with lower intonations within sessions. We did not find any effects of the variables considered on cortisol variation. Our study highlights the relevance of voice tone and speech in a training context on animals' performances and emotional reactions.

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

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

Thermography as a tool to assess training effects in military working dogs

Military working dogs are exposed to high levels of physical load during their work, although this is not always evident from their behaviour. This workload causes various physiological changes, including variation in the temperature of the affected body parts. In this preliminary study, we investigated whether thermal changes following the daily work routine of military dogs are detectable by infrared thermography (IRT). The experiment was carried out on eight male German and Belgian shepherd patrol guard dogs performing two training activities, obedience and defence. The surface temperature (Ts) of 12 selected body parts on both body sides was measured with the IRT camera 5 min before, 5 min after and 30 min after training. As predicted, there was a greater increase in Ts (mean of all measured body parts) after defence than after obedience, 5 min (by 1.24 vs. 0.60 °C, P < 0.001) and 30 min after activity (by 0.90vs. 0.57 °C, P < 0.01) compared to pre-activity levels. These findings indicate that defence is more physically demanding than obedience activity. Considering the activities separately, obedience increased Ts 5 min after the activity only in the trunk (P < 0.001) but not in the limbs, whereas defence increased it in all measured body parts (P < 0.001). Ts 30 min after obedience decreased to the pre-activity level in parts at trunk, while in distal parts of the limbs Ts remained elevated. The prolonged elevation in Ts of the limbs after both activities indicates heat flow from the core to the periphery as a thermoregulatory mechanism. The current study suggests that IRT may be a useful tool for assessing physical workload in different body parts of dogs.

Is the Weight of the Newborn Puppy Related to Its Thermal Balance?

Hypothermia, a factor associated with neonatal mortality, can occur immediately after birth as a protective mechanism to prevent hypoxic damage in neonates, or to reduce the metabolic rate to improve the chances of survival in the first hours of life. The heat interchange through the superficial temperature of animals can be evaluated with infrared thermography (IRT). However, to date, there is no information on thermal windows in puppies. This study aimed to evaluate, with the use of IRT, the microcirculatory alterations in 8 different thermal windows identified at 7 different times in 289 newborn puppies assigned to different groups. Three thermograms were taken from four zones of each puppy: the facial, frontal, right lateral, and left lateral regions. Newborn puppies were grouped in 4 quartiles according to their weight: Q1 (126−226 g) n = 73, Q2 (227−330 g) n = 72, Q3 (331−387 g) n = 74, and Q4 (388−452 g) n = 70. A total of 8 thermal windows were considered at 7 evaluation times from Wet at birth until 24 h after birth (AB). Two-way mixed ANOVA within and between subjects’ design for each thermal window (eight models) was performed. Results revealed a positive correlation between the puppy’s weight and its ability to achieve thermostability in all the evaluated thermal windows. Statistically significant differences (p < 0.0001) between the 4 quartiles (Q1, Q2, Q3, and Q4) were found. The lowest temperatures were recorded when the pups were still wet and the highest at 24 h AB. Thermal windows with the highest temperatures were abdominal (34.234 ± 0.056 °C), thoracic (33.705 ± 0.049 °C), nasal (30.671 ± 0.110 °C), and upper left palpebral (34.066 ± 0.052 °C), while the lowest were thoracic limb brachial biceps (27.534 ± 0.051 °C), thoracic limb elbow (27.141 ± 0.049 °C), thoracic limb metacarpal (27.024 ± 0.062 °C), and femoral pelvic limb (27.654 ± 0.055 °C). Assessing the thermal response in newborn puppies can help identify drastic temperature reductions or deficient thermoregulatory compensation during the first hours of life, preventing the consequences of hypothermia.

Dogs functionally respond to and use emotional information from human expressions

Emotions are critical for humans, not only feeling and expressing them, but also reading the emotional expressions of others. For a long time, this ability was thought to be exclusive to people; however, there is now evidence that other animals also rely on emotion perception to guide their behaviour and to adjust their actions in such way as to guarantee success in their social groups. This is the case for domestic dogs, who have tremendously complex abilities to perceive the emotional expressions not only of their conspecifics but also of human beings. In this paper we discuss dogs' capacities to read human emotions. More than perception, though, are dogs able to use this emotional information in a functional way? Does reading emotional expressions allow them to live functional social lives? Dogs can respond functionally to emotional expressions and can use the emotional information they obtain from others during problem-solving, that is, acquiring information from faces and body postures allows them to make decisions. Here, we tackle questions related to the abilities of responding to and using emotional information from human expressions in a functional way and discuss how far dogs can go when reading our emotions.

Relation between the Dam's Weight on Superficial Temperature of Her Puppies at Different Stages of the Post-Partum

The thermal stability of newborns is an essential parameter that can be recorded to evaluate neonatal care. Knowing the thermal windows to evaluate and maintain a constant temperature helps significantly reduce neonatal mortality. This study aimed to assess the superficial temperature alterations in the distinct thermal windows of puppies with mothers of diverse weights and their repercussions. We evaluated the superficial temperature using infrared thermography at eight thermal windows and seven different times: when wet due to the fetal fluid immediately after birth until 24 h of life in newborn puppies from bitches divided into four bodyweight groups. The results revealed a positive correlation between the dam's weight and the ability to achieve thermostability in the newborn puppies in all the evaluated thermal windows. The time effect showed the lowest temperatures when the puppies were still wet, a gradual increase, and the highest temperature at 24 h after birth. The thermal windows with the highest temperatures were abdominal, thoracic, nasal, and upper left palpebral, and those with the lowest were the thoracic limb brachial biceps, thoracic limb elbow, metacarpal, and femoral pelvic limb. A significant increase in the temperatures in the thermal windows of the abdominal, thoracic, and upper left palpebral immediately after ingesting colostrum was observed. The weight of the dams is an important factor that positively intervenes in the thermoregulatory capacity of the puppies, especially when newborns are dry and have been passed 24 h after birth.

Urban gulls show similar thermographic and behavioral responses to human shouting and conspecific alarm calls

Rapid population growth and the urbanization of modern environments are markedly increasing human-wildlife conflict. Wild animals in urban landscapes can benefit from exploiting human resources, but are also exposed to increased risk of human-caused injury, which should favor the ability to perceive and respond to human cues. Although it is well known that domesticated animals use human cues that may indicate threats, less is known about wild animals living in urban environments. Herring gulls (Larus argentatus) in urban landscapes have adapted kleptoparasitic behaviors to obtain human food, often resulting in negative interactions with humans. Here we quantified both the behavioral and physiological responses of free-living urban herring gulls to human shouting. We presented urban gulls with a fake human food item and played back recordings of either a man shouting, a natural stressor (i.e., conspecific alarm call), or a neutral stimulus (i.e., robin song). We recorded behavioral responses and used non-invasive infrared thermography to measure eye-region surface temperature changes associated with the avian physiological stress response. We found that gulls exposed to shouting and to conspecific alarm calls showed similar changes in behavior (indicating high levels of vigilance) and eye-region surface temperature (indicating physiological stress). Both responses were significantly stronger than the responses to robin song. Additionally, the behavioral and physiological responses were positively correlated across individuals. Our results demonstrate that urban-dwelling gulls respond to human shouting and conspecific alarm calls in a similar way, and suggest that infrared thermography is a viable technique to monitor stress responses in free-living birds.

Audience effect on domestic dogs' behavioural displays and facial expressions

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

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

Simple Summary

The relationship between owner and the dog affects the dog’s attachment behaviors and stress coping. In turn, the quality of the relationship may affect owner’s interpretations about their dog’s behavior. Here, we assessed dogs’ emotional responses from heart rate variability and behavioral changes during five different situations. Dog owners evaluated the emotion (valence and arousal) of their dog after each situation. We found that both negative and positive incidents provoked signs of emotional arousal in dogs. Owners detected the dog’s arousal especially during fear- and stress-evoking situations. The dog–owner relationship did not affect owners’ interpretation of dogs’ emotion. However, the dog–owner relationship was reflected in the dog’s emotional reactions. Close emotional bond with the owner appeared to decrease the arousal of the dogs. Dog owners’ frequent caregiving of their dog was associated with increased attachment behaviors and heightened arousal of dogs. Owners rated the disadvantages of the dog relationship higher for the dogs that were less owner-oriented and less arousable. Dog’s arousal may provoke dog’s need to seek human attention, which in turn may promote the development of emotional bond.

Abstract

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

Thermal and Circulatory Changes in Diverse Body Regions in Dogs and Cats Evaluated by Infrared Thermography

Infrared thermography (IRT) has been proposed as a method for clinical research to detect local inflammatory processes, wounds, neoplasms, pain, and neuropathies. However, evidence of the effectiveness of the thermal windows used in dogs and cats is discrepant. This review aims to analyze and discuss the usefulness of IRT in diverse body regions in household animals (pets) related to recent scientific evidence on the use of the facial, body, and appendicular thermal windows. IRT is a diagnostic method that evaluates thermal and circulatory changes under different clinical conditions. For the face, structures such as the lacrimal caruncle, ocular area, and pinna are sensitive to assessments of stress degrees, but only the ocular window has been validated in felines. The usefulness of body and appendicular thermal windows has not been conclusively demonstrated because evidence indicates that biological and environmental factors may strongly influence thermal responses in those body regions. The above has led to proposals to evaluate specific muscles that receive high circulation, such as the bicepsfemoris and gracilis. The neck area, perivulvar, and perianal regions may also prove to be useful thermal windows, but their degree of statistical reliability must be established. In conclusion, IRT is a non-invasive technique that can be used to diagnose inflammatory and neoplastic conditions early. However, additional research is required to establish the sensitivity and specificity of these thermal windows and validate their clinical use in dogs and cats.

Neuroendocrine and Cardiovascular Activation During Aggressive Reactivity in Dogs

Our aim was to investigate cardiovascular activation by measuring changes in facial and body surface temperature using infrared thermography, and neuroendocrine activation using salivary cortisol (CORT) and serotonin concentration (SER) in dogs exhibiting aggressive reactivity in real time. Based on two factors, owner-reported past aggressive behaviors, and detailed behavioral observations collected during a Socially Acceptable Behavior test consisting of 16 subtests and, each individual was categorized as aggressive or non-aggressive. CORT and SER showed no difference in neuroendocrine activity between dogs, but aggressive dogs with higher levels of aggression were found to have lower SER. Aggressive dogs also had an increase in facial temperature from pre-test values. The discovery of a correlation between tail wagging and left tail wagging with aggression level and aggression-related behaviors in aggressive dogs is further evidence of the right hemisphere specialization for aggression previously reported in the literature. This study provides the first evidence that both cardiovascular and neuroendocrine systems are activated during an active act of aggression in dogs.

Infrared Thermography in the Study of Animals' Emotional Responses: A Critical Review

Simple Summary

Assessing animal welfare has proven to be a challenging task with important consequences for their management. In the last few years, infrared thermography has gained increasing scientific consensus as a method to analyze emotional reactions to different stimuli in different taxa. This review aims to explore particularly the use of infrared thermography in the assessment of animals’ emotions, mainly focusing on pets, laboratory, and husbandry animals. If properly used, this technique has proven to be a noninvasive, reliable method to identify emotional activations.

Abstract

Whether animals have emotions was historically a long-lasting question but, today, nobody disputes that they do. However, how to assess them and how to guarantee animals their welfare have become important research topics in the last 20 years. Infrared thermography (IRT) is a method to record the electromagnetic radiation emitted by bodies. It can indirectly assess sympathetic and parasympathetic activity via the modification of temperature of different body areas, caused by different phenomena such as stress-induced hyperthermia or variation in blood flow. Compared to other emotional activation assessment methods, IRT has the advantage of being noninvasive, allowing use without the risk of influencing animals’ behavior or physiological responses. This review describes general principles of IRT functioning, as well as its applications in studies regarding emotional reactions of domestic animals, with a brief section dedicated to the experiments on wildlife; it analyzes potentialities and possible flaws, confronting the results obtained in different taxa, and discusses further opportunities for IRT in studies about animal emotions.

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

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

Equine-Assisted Interventions (EAIs) for Children with Autism Spectrum Disorders (ASD): Behavioural and Physiological Indices of Stress in Domestic Horses (Equus caballus) during Riding Sessions

Equine-assisted interventions (EAIs) are well-known complementary practices combining physical activity with emotional/cognitive stimulation. They are especially suited for children with autism spectrum disorders (ASD) who need a high degree of physical and psychological enrichment. Even though EAIs have become a common practice, stress responses in horses interacting with individuals that can manifest inappropriate behaviours, such as ASD children, have not been thoroughly investigated. Our multicentre study aimed to investigate behavioural and physiological indices of stress in horses involved in EAI standardised sessions with children with ASD compared to typically developing (TD) children. A controlled within-subject design with repeated measurements involving 19 horses and 38 children was adopted. Stress-related behaviours, heart rate, heart rate variability, and eye temperature were recorded during the riding sessions. Moreover, blood samples were collected from horses before and after each session to monitor changes in blood adrenocorticotropic hormone (ACTH), cortisol, and catecholamines. Results indicate that, in general, stress responses in horses involved in EAIs did not differ as a function of the horse being ridden by children with ASD or TD. A lower sympathetic tone in horses involved in ASD sessions was found, while in the mounting and dismounting phases, horses displayed behavioural signs of stress, independently from children's behaviour. We conclude that professionals working in EAI should increase their awareness of animal welfare and refine riding practices, taking into account horse's needs.

Can Dogs' Origins and Interactions with Humans Affect Their Accomplishments? A Study on the Responses of Shelter and Companion Dogs during Vocal Cue Training

Simple Summary

The life history of animals is an important aspect to be considered when behavior, welfare, or cognition is investigated. Here, we aimed to study the behavioral responses of dogs with different origins—shelter and companion dogs—when learning two basic vocal cues (“sit” and “paw”), as well as possible associations between dogs’ responses and the behaviors of the trainers. Shelter dogs responded to more cues per session, were faster in their responses, and needed fewer repetitions of cues to respond than companion dogs. Moreover, shelter dogs spent more time wagging their tails during the sessions. Some behaviors of the trainers were associated with dogs’ behaviors—the use of a reproachful tone of voice, although associated with dog performance, was also linked to the exhibition of behaviors indicative of discomfort on the part of dogs. On the other hand, the use of a neutral tone of voice and laughter, in addition to being connected to performance, was also associated with behaviors indicative of excitement. These results suggest that shelter dogs’ capacities for learning vocal cues are not affected by the shelter environment. Furthermore, shelter dogs showed greater interest in the sessions than companion dogs, possibly due to the social deprivation in their routine. Our outcomes also point to a connection between friendly interactions during training and the dogs’ performance, and possibly their emotional state. The quality of the interactions seems to affect dogs’ performance and welfare more strongly than their origins.

Abstract

The inclusion of life history as a possible influential factor is pivotal in studies on behavior, welfare, and cognition. Shelter dogs have usually experienced a life involving poor social interactions with humans. Thus, we aimed to investigate the behavioral responses of shelter dogs (SDs) and companion dogs (CDs) during the training of two vocal cues (“sit”, “paw”), as well as the possible associations between their responses and the behaviors of trainers. We studied 15 SDs and 15 CDs in up to eight five-minute training sessions. Dogs’ and trainers’ behaviors were recorded and analyzed (through GLM, GLMM, correlation and Mann–Whitney tests). Shelter dogs responded to more cues per session, with shorter latencies and fewer repetitions of cues. Moreover, SDs spent more time wagging their tails. Dogs’ sex and trainers’ behaviors were also associated with differences in dogs’ responses. The use of a reproachful tone of voice was associated with a greater number of cues responded to, shorter latencies, and fewer repetitions of cues. However, this type voice/discourse was also linked to a greater exhibition of non-training behaviors (e.g., exploring the room or jumping on the trainer), and to dogs spending less time next to the trainer and wagging their tails. On the other hand, the use of a neutral tone of voice and laughter, besides being linked to performance, was also associated with longer durations of tail wagging. Furthermore, the duration of the trainers’ orientation to dogs was correlated with the orientation of the dogs to the trainers. Our data suggest that, even when having experienced social deprivation from humans, SDs’ capacities to learn vocal cues were preserved, possibly due to ontogenic homeostasis processes. Shelter dogs’ greater interest in the sessions may be also credited to their socially-deprived routine. Our outcomes also point to an association between friendly interactions during training and dog performance and excitement, which suggests that such interactions may have the potential to improve SD welfare.

'Puppy Dog Eyes' Are Associated With Eye Movements, Not Communication

The inner brow raiser is a muscle movement that increases the size of the orbital cavity, leading to the appearance of so-called 'puppy dog eyes'. In domestic dogs, this expression was suggested to be enhanced by artificial selection and to play an important role in the dog-human relationship. Production of the inner brow raiser has been shown to be sensitive to the attentive stance of a human, suggesting a possible communicative function. However, it has not yet been examined whether it is sensitive to human presence. In the current study, we aimed to test whether the inner brow raiser differs depending on the presence or absence of an observer. We used two versions of a paradigm in an equivalent experimental setting in which dogs were trained to expect a reward; however, the presence/absence of a person in the test apparatus was varied. In the social context, a human facing the dog delivered the reward; in the non-social context, reward delivery was automatized. If the inner brow raiser has a communicative function and dogs adjust its expression to an audience, we expect it to be shown more frequently in the social context (when facing a person in the apparatus) than in the non-social context (when facing the apparatus without a person inside). The frequency of the inner brow raiser differed between the two contexts, but contrary to the prediction, it was shown more frequently in the non-social context. We further demonstrate that the inner brow raiser is strongly associated with eye movements and occurs independently in only 6% of cases. This result challenges the hypothesis that the inner brow raiser has a communicative function in dog-human interactions and suggests a lower-level explanation for its production, namely an association with eye movements.

Influences on Infrared Thermography of the Canine Eye in Relation to the Stress and Arousal of Racing Greyhounds

Simple Summary

To improve the welfare of racing greyhounds, the identification of stressful industry practices is required. One potential method for monitoring stress in greyhounds is infrared thermography, which measures surface temperature. This article reports on the use of eye temperature, which may increase after a stressful event. The location on the eye that temperature is taken from is likely to be critical to the measurements. This study monitored 465 greyhounds racing at three racetracks in New South Wales. It found that the right eye and lacrimal caruncle (the inner corner of the eye) revealed temperature changes most effectively. Eye temperatures increased after racing, which may be due to physical exertion, stress and arousal. Additionally, eye temperature was higher in dogs that waited longer to race. Dogs at Richmond racetrack had lower eye temperatures before racing, but higher eye temperatures after racing compared to those at the Wentworth Park and Gosford racetrack. Other factors that increased eye temperature included humidity and a dog’s coat colour, age and final placing. Greyhounds that have light-coloured coats, are younger or placed poorly may be more stressed after racing. These factors need to be considered so that stress can be accurately detected.

Abstract

Infrared thermography (IRT) can be used to identify stressors associated with greyhound racing procedures. However, factors unrelated to stress may influence measurements. Validation of an eye side (right or left) and a reference point on the eye is required if IRT is to be standardised for industry use. Infrared images of greyhound heads (n = 465) were taken pre-racing and post-racing at three racetracks. Average temperature was recorded at seven different locations on each eye. A multivariate analysis model determined how several factors influenced eye temperature (ET) pre-racing and post-racing. As expected, ET increased after racing, which may be attributed to physical exertion, stress and arousal. The right eye and lacrimal caruncle had the highest sensitivity to temperature changes and could be considered reference points for future studies. Additionally, dogs that raced later had higher ET, and Richmond racetrack had the lowest pre-race ET, but the highest post-race ET. This may suggest that arousal increases as the race meet progresses and certain track attributes could increase stress. Furthermore, ET increased as humidity increased, and higher post-race ET was associated with light-coloured, young and low-performing dogs. Environmental and biological factors need to be considered if IRT is to become accurate in the detection of canine stress and monitoring of greyhound welfare.

Social Context Influences Resting Physiology in Dogs

Domestication has affected the social life of dogs. They seem to be less dependent on their pack members than wolves, potentially causing dogs to be more alert towards their environment, especially when resting. Such a response has been found in dogs resting alone compared to wolves in the same situation. However, as this may be influenced by social context, we compared alertness (i.e., degree of activation along the sleep-wake continuum-measured via cardiac parameters) of pack-living and enclosure-kept dogs in two conditions: (1) alone, and (2) with pack members, and in two states of activation: (1) inactive wakefulness, and (2) resting. We found that when dogs were resting alone, alertness was higher than when resting in the pack; individual alertness was potentially influenced by social rank. However, alertness was similar in the two conditions during inactive wakefulness. Thus, depending on social context, familiar conspecifics may still provide support in dogs; i.e., domestication has probably only partly shifted the social orientation of dogs from conspecifics to humans. We suggest that cardiac responses of dogs may be more flexible than those of wolves because of their adaptation to the more variable presence of humans and conspecifics in their environment.

Talking to Cows: Reactions to Different Auditory Stimuli During Gentle Human-Animal Interactions

The quality of the animal-human relationship and, consequently, the welfare of animals can be improved by gentle interactions such as stroking and talking. The perception of different stimuli during these interactions likely plays a key role in their emotional experience, but studies are scarce. During experiments, the standardization of verbal stimuli could be increased by using a recording. However, the use of a playback might influence the perception differently than "live" talking, which is closer to on-farm practice. Thus, we compared heifers' (n = 28) reactions to stroking while an experimenter was talking soothingly ("live") or while a recording of the experimenter talking soothingly was played ("playback"). Each animal was tested three times per condition and each trial comprised three phases: pre-stimulus, stimulus (stroking and talking) and post-stimulus. In both conditions, similar phrases with positive content were spoken calmly, using long low-pitched vowels. All tests were video recorded and analyzed for behaviors associated with different affective states. Effects on the heifers' cardiac parameters were assessed using analysis of heart rate variability. Independently of the auditory stimuli, longer durations of neck stretching occurred during stroking, supporting our hypothesis of a positive perception of stroking. Observation of ear positions revealed longer durations of the "back up" position and less ear flicking and changes of ear positions during stroking. The predicted decrease in HR during stroking was not confirmed; instead we found a slightly increased mean HR during stroking with a subsequent decrease in HR, which was stronger after stroking with live talking. In combination with differences in HRV parameters, our findings suggest that live talking might have been more pleasurable to the animals and had a stronger relaxing effect than "playback." The results regarding the effects of the degree of standardization of the stimulus on the variability of the data were inconclusive. We thus conclude that the use of recorded auditory stimuli to promote positive affective states during human-animal interactions in experimental settings is possible, but not necessarily preferable.

Where Do We Stand in the Domestic Dog ( Canis familiaris ) Positive-Emotion Assessment: A State-of-the-Art Review and Future Directions

Although there have been a growing number of studies focusing on dog welfare, the research field concerning dog positive-emotion assessment remains mostly unexplored. This paper aims to provide a state-of-the-art review and summary of the scattered and disperse research on dog positive-emotion assessment. The review notably details the current advancement in dog positive-emotion research, what approaches, measures, methods, and techniques have been implemented so far in emotion perception, processing, and response assessment. Moreover, we propose possible future research directions for short-term emotion as well as longer-term emotional states assessment in dogs. The review ends by identifying and addressing some methodological limitations and by pointing out further methodological research needs.

A Pilot Study of Methods for Evaluating the Effects of Arousal and Emotional Valence on Performance of Racing Greyhounds

Simple Summary

Racing greyhounds in Australia may have their racing careers ended early if they do not reliably chase the lure. It is not known why greyhounds bred specifically to chase may fail to do so, but possible reasons may be they are overly distressed by the race meet environment, or they get frustrated that they are not able to capture the lure. The current study sought ways to investigate these possibilities by exploring potential indicators of arousal and frustration in greyhounds at race meets across three different racetracks in New South Wales (NSW). Eye temperature offers a non-invasive, objective way to assess arousal. Behaviour thought to indicate arousal was also recorded. Finally, behaviour was recorded at the end of races to seek indications of frustration. Greyhounds that were older and had higher eye temperatures after the race performed worse in their races. Eye temperature before races was affected by the racetrack at which the race meet was held as well as the race number, suggesting some tracks may be more stressful for greyhounds than others, and that kennelling is probably a source of ongoing distress at race meets. Frustration-related behaviours were common at two of the tracks but less common at the third, where toys were available in the catch pen.

Abstract

The racing greyhound industry in Australia has come under scrutiny in recent years due to animal welfare concerns, including wastage where physically sound greyhounds fail to enter or are removed from the racing industry because of poor performance. The reasons why some greyhounds perform poorly in racing are not well understood, but may include insufficient reinforcement for racing or negative affective states in response to the race meet environment. The current study investigated ways to measure affective states of greyhounds (n = 525) at race meets across three racetracks and the factors influencing performance by collecting behavioural and demographic data, and infrared thermographic images of greyhounds’ eyes at race meets. Increasing Eye Temp After had a negative association with performance (n = 290, Effect = −0.173, s.e. = 0.074, p-value = 0.027), as did increasing age (n = 290, Effect = −0.395, s.e. = 0.136, p-value = 0.004). The start box number also had a significant association, with boxes 4, 5 and 7 having an inverse relationship with performance. There was a significant effect of racetrack on mean eye temperatures before and after the race (n = 442, Effect = 1.910, s.e. = 0.274, p-value < 0.001; Effect = 1.595, s.e. = 0.1221, p-value < 0.001 for Gosford and Wentworth respectively), suggesting that some tracks may be inherently more stressful for greyhounds than others. Mean eye temperature before the race increased as the race meet progressed (n = 442, Effect = 0.103, s.e. = 0.002, p-value < 0.001). Behaviours that may indicate frustration in the catching pen were extremely common at two of the tracks but much less common at the third, where toys attached to bungees were used to draw greyhounds into the catching pen.

The Human-Animal Relationship as the Focus of Animal-Assisted Interventions: A One Health Approach

BACKGROUND

Animal-assisted intervention (AAIs) represent an adequate expression of integrated medicine, according to the One Health approach. We argue that AAIs are interventions based on interspecific relationships between humans and animals. Although there are many studies on the effects of AAIs on animal and human health and wellbeing, research is still needed to give us more data. For example, information is still lacking on the aspects characterizing and influencing the interspecific relationships occurring in AAIs. The efficacy of an intervention based on interspecific relationships will be influenced by different factors, such as attachment styles and personalities of both the animal and the handler, an appropriate choice of animal species and their individuality, animal educational training techniques, the relationship between the handler and the animal, and relational reciprocity between animal, the patients, and members of the working team.

METHOD

This article aims to contribute to the study of interspecific relationships in AAIs via theoretical considerations. An interspecific relationship determines the result of safe interventions, which directly influences the welfare of the animal. Results and considerations: AAIs should be evaluated systemically as a network within a process in which every component interacts with and influences other components. Standardized methods using appropriate tests and parameters are needed to better select appropriate animals (i.e., species and individual subjects) using interspecific relational competences as well as appropriate educational training methods and health protocols to assess potential risks.

Potential Physiological Parameters to Indicate Inner States in Dogs: The Analysis of ECG, and Respiratory Signal During Different Sleep Phases

The sleeping activity of family dogs has been studied increasingly in the past years. Recently, a validated, non-invasive polysomnographic method has been developed for dogs, enabling the parallel recording of several neurophysiological signals on non-anesthetized family dogs, including brain activity (EEG), eye movements (EOG), cardiac (ECG), and respiratory activity (PNG). In this study, we examined the ECG (N = 30) and respiratory signals (N = 19) of dogs during a 3-h sleep period in the afternoon, under laboratory conditions. We calculated four time-domain heart rate variables [mean heart rate (HR), SDNN, RMSSD, and pNN50] from the ECG and the estimated average respiratory frequency from the respiratory signal. We analyzed how these variables are affected by the different sleep-wake phases (wakefulness, drowsiness, NREM, and REM) as well as the dogs’ sex, age and weight. We have found that the sleep-wake phase had a significant effect on all measured cardiac parameters. In the wake phase, the mean HR was higher than in all other phases, while SDNN, RMSSD, and pNN50 were lower than in all other sleep phases. In drowsiness, mean HR was higher compared to NREM and REM phases, while SDNN and RMSSD was lower compared to NREM and REM phases. In REM, SDNN, and RMSSD was higher than in NREM. However, the sleep-wake phase had no effect on the estimated average respiratory frequency of dogs. The dogs’ sex, age and weight had no effect on any of the investigated variables. This study represents a detailed analysis of the cardiac and respiratory activity of dogs during sleep. Since variations in these physiological signals reflect the dynamics of autonomic functions, a more detailed understanding of their changes may help us to gain a better understanding of the internal/emotional processes of dogs in response to different conditions of external stimuli. As such, our results are important since they are directly comparable to human findings and may also serve as a potential basis for future studies on dogs.

Symposium review: Scientific assessment of affective states in dairy cattle

Affective states, which refer to feelings or emotions, are a key component of animal welfare, but these are also difficult to assess. Drawing upon a body of theoretical and applied work, we critically review the scientific literature on the assessment of affective states in animals, drawing examples where possible from research on dairy cattle, and highlighting the strengths and weaknesses of scientific methods used to assess affective states in animals. We adopt the "valence/arousal" framework, describing affect as a 2-dimensional space (with valence referring to whether an experience is positive or negative, and arousal referring to the intensity of the experience). We conclude that spontaneous physiological and behavioral responses typically reflect arousal, whereas learned responses can be valuable when investigating valence. We also conclude that the assessment of affective states can be furthered using mood assessments and that the use of drug treatments with known emotional effects in humans can be helpful in the assessment of specific affective states in animals.

Changes of Oxytocin and Serotonin Values in Dialysis Patients after Animal Assisted Activities (AAAs) with a Dog—A Preliminary Study

Our study aimed to measure the levels of serotonin and oxytocin in patients affected by end-stage renal disease (ESRD), undergoing dialysis and participating in a program of animal-assisted activities (AAAs) with a dog. Ten patients with comparable levels of ESRD were enrolled. A blood sample was taken before the start of the study in order to establish basal levels. Eleven meetings were held once a week for 3 months during the last hour of dialysis, and blood samples were collected before and after AAAs. Two more meetings, one month apart from each other, were held two months later without the dog but with the same veterinarian zootherapist. Blood was drawn at the beginning and at the end of each meeting. The samples were then processed for the measurement of serotonin and oxytocin, and data obtained were analysed using analysis of variance with mixed effect models. The results show an increasing level of both serotonin and oxytocin between subsequent meetings with the dog and an increasing trend of inter-intervention levels. Overall, the results suggest that AAAs lead to modifications of serotonin and oxytocin levels, which are also accompanied by behavioural changes of patients.

Infrared thermography of agonistic behaviour in pigs

Infrared thermography (IRT) or thermal imaging is increasingly being used as a non-invasive method to gain information on animals' physiological and emotional state. IRT has the potential to serve as a non-invasive quantitative assessment method but few studies have examined its utility in predicting welfare-relevant outcomes of dynamic scenarios relevant to commercial farming. This study used 1284 thermal images taken from 46 pigs in a controlled test environment while they engaged in an agonistic encounter (dyadic contest) at 13 wk. of age. Images were taken of the complete body from a dorsal perspective. A pilot study indicated that a rectangular thermal window on the back region was the most suitable and reliable area for obtaining temperature data in this situation. From this thermal window, the average, minimum and maximum temperature, standard deviation and coefficient of variation (CV) were obtained. These were analysed in relation to contest phase (from non-contact assessment, through escalated fighting to retreat), fight occurrence, contest duration, contest outcome (winner/loser status) and changes in blood glucose, blood lactate, and skin injuries. Variables showed a strong change in response to the moment of contest resolution (retreat of the loser); temperatures reduced sharply and CV increased, but did not differ between winners and losers. Contests that included a fight showed lower temperatures. Contest duration, body weight and sex only had minor influences on the temperatures. As the drop in temperature at contest resolution was irrespective of contest intensity, and the pattern was similar in winners and losers, this data potentially reflects vasoconstriction as a result of psychological stress rather than solely a physiological change. The study shows that peripheral temperature, as recorded by IRT, responds to the intensity and phases of a contest and may allow new insight into the physiological and welfare outcomes of aggressive behaviour.

Goats distinguish between positive and negative emotion-linked vocalisations

Background

Evidence from humans suggests that the expression of emotions can regulate social interactions and promote coordination within a group. Despite its evolutionary importance, social communication of emotions in non-human animals is still not well understood. Here, we combine behavioural and physiological measures, to determine if animals can distinguish between vocalisations linked to different emotional valences (positive and negative). Using a playback paradigm, goats were habituated to listen to a conspecific call associated with positive or negative valence (habituation phase) and were subsequently exposed to a variant of the same call type (contact call) associated with the opposite valence (dishabituation phase), followed by a final call randomly selected from the habituation phase as control (rehabituation phase). The effects of the calls on the occurrence of looking and cardiac responses in these phases were recorded and compared.

Results

We found that when the valence of the call variant changed, goats were more likely to look at the source of the sound, indicating that they could distinguish calls based on their valence. Heart rate was not affected by the valence of the calls played, whereas heart-rate variability tended to be higher in the habituation and rehabituation phases, when positive calls were played compared to negative ones. Together, the behavioural and physiological measures provide evidence suggesting, first, that goats are able to distinguish call variants based on their valence, and second, that goat behaviour and cardiac responses are affected by call valence.

Conclusion

This study indicates that auditory modalities are a potent means to communicate emotions in non-human animals. These findings can contribute to our understanding of the evolution of emotion perception in non-human animals.

Negative emotional contagion and cognitive bias in common ravens (Corvus corax)

Emotional contagion is described as an emotional state matching between subjects, and has been suggested to facilitate communication and coordination in complex social groups. Empirical studies typically focus on the measurement of behavioral contagion and emotional arousal, yet, while highly important, such an approach often disregards an additional evaluation of the underlying emotional valence. Here, we studied emotional contagion in ravens by applying a judgment bias paradigm to assess emotional valence. We experimentally manipulated positive and negative affective states in demonstrator ravens, to which they responded with increased attention and interest in the positive condition, as well as increased redirected behavior and a left-eye lateralization in the negative condition. During this emotion manipulation, another raven observed the demonstrator's behavior, and we used a bias paradigm to assess the emotional valence of the observer to determine whether emotional contagion had occurred. Observers showed a pessimism bias toward the presented ambiguous stimuli after perceiving demonstrators in a negative state, indicating emotional state matching based on the demonstrators' behavioral cues and confirming our prediction of negative emotional contagion. We did not find any judgment bias in the positive condition. This result critically expands upon observational studies of contagious play in ravens, providing experimental evidence that emotional contagion is present not only in mammalian but also in avian species. Importantly, this finding also acts as a stepping stone toward understanding the evolution of empathy, as this essential social skill may have emerged across these taxa in response to similar socioecological challenges.

Valence and Intensity of Video Stimuli of Dogs and Conspecifics in Sheep: Approach-Avoidance, Operant Response, and Attention

Simple Summary

Animals’ judgement of stimuli’s negativity or positivity cannot always be assumed. To assess the valence and intensity of video stimuli (dogs as negative vs. conspecifics as positive stimuli) in sheep, we used three experimental approaches: (1) an approach-avoidance paradigm; (2) operant conditioning using the videos as reinforcers; and (3) an attention test. We measured sheep’s behavioral and physiological reactions. Sheep generally reacted to the videos presented. Nevertheless, we found no support with the approach–avoidance paradigm, and the attention test for dog videos were more negative than sheep videos. However, the operant conditioning indicated that sheep were more prone to avoid videos of moving dogs. Overall, we found that standard video images may not be ideal to represent valence characteristics of stimuli to sheep.

Abstract

Stimuli are often presumed to be either negative or positive. However, animals’ judgement of their negativity or positivity cannot generally be assumed. A possibility to assess emotional states in animals elicited by stimuli is to investigate animal preferences and their motivation to gain access to these stimuli. This study’s aim was to assess the valence of social stimuli in sheep. We used silent videos of varying intensity of dogs as negative versus conspecifics as positive stimuli in three approaches: (1) an approach–avoidance paradigm; (2) operant conditioning using the video stimuli as reinforcers; and (3) an attention test. In the latter, we assessed differential attention of sheep to simultaneous projections by automatically tracking sheep head and ear postures and recording brain activity. With these approaches, it was difficult to support that the sheep’s reactions varied according to the stimuli’s presumed valence and intensity. The approach–avoidance paradigm and attention test did not support the assumption that dog videos were more negative than sheep videos, though sheep reacted to the stimuli presented. Results from the operant conditioning indicated that sheep were more prone to avoid videos of moving dogs. Overall, we found that standard video images may not be ideal to represent valence characteristics of stimuli to sheep.

Skin temperature and reproductive condition in wild female chimpanzees

Infrared thermal imaging has emerged as a valuable tool in veterinary medicine, in particular for evaluating reproductive processes. Here, we explored differences in skin temperature of twenty female chimpanzees in Budongo Forest, Uganda, four of which were pregnant during data collection. Based on previous literature in other mammals, we predicted increased skin temperature of maximally swollen reproductive organs of non-pregnant females when approaching peak fertility. For pregnant females, we made the same prediction because it has been argued that female chimpanzees have evolved mechanisms to conceal pregnancy, including swellings of the reproductive organs, conspicuous copulation calling, and solicitation of male mating behaviour, to decrease the infanticidal tendencies of resident males by confusing paternity. For non-pregnant females, we found slight temperature increases towards the end of the swelling cycles but no significant change between the fertile and non-fertile phases. Despite their different reproductive state, pregnant females had very similar skin temperature patterns compared to non-pregnant females, suggesting little potential for males to use skin temperature to recognise pregnancies, especially during maximal swelling, when ovulation is most likely to occur in non-pregnant females. We discuss this pattern in light of the concealment hypothesis, i.e., that female chimpanzees have evolved physiological means to conceal their reproductive state during pregnancy.

Utilising dog-computer interactions to provide mental stimulation in dogs especially during ageing

Aged dogs suffer from reduced mobility and activity levels, which can affect their daily lives. It is quite typical for owners of older dogs to reduce all activities such as walking, playing and training, since their dog may appear to no longer need them. Previous studies have shown that ageing can be slowed by mental and physical stimulation, and thus stopping these activities might actually lead to faster ageing in dogs, which can result in a reduction in the quality of life of the animal, and may even decrease the strength of the dog-owner bond. In this paper, we describe in detail a touchscreen apparatus, software and training method that we have used to facilitate dog computer interaction (DCI). We propose that DCI has the potential to improve the welfare of older dogs in particular through cognitive enrichment. We provide hypotheses for future studies to examine the possible effects of touchscreen use on physiological, behavioural and cognitive measures of dogs' positive affect and well-being, and any impact on the dog-owner bond. In the future, collaborations between researchers in animal-computer interaction, dog trainers, and cognitive scientists are essential to develop the hardware and software necessary to realise the full potential of this training and enrichment tool.

Human attention affects facial expressions in domestic dogs

Most mammalian species produce facial expressions. Historically, animal facial expressions have been considered inflexible and involuntary displays of emotional states rather than active attempts to communicate with others. In the current study, we aimed to test whether domestic dog facial expressions are subject to audience effects and/ or changes in response to an arousing stimulus (e.g. food) alone. We presented dogs with an experimental situation in which a human demonstrator was either attending to them or turned away, and varied whether she presented food or not. Dogs produced significantly more facial movements when the human was attentive than when she was not. The food, however, as a non-social but arousing stimulus, did not affect the dogs’ behaviour. The current study is therefore evidence that dogs are sensitive to the human’s attentional state when producing facial expressions, suggesting that facial expressions are not just inflexible and involuntary displays of emotional states, but rather potentially active attempts to communicate with others.