Behavioural, saliva cortisol and heart rate responses to different types of stimuli in dogs

Dose-dependent responses: a preliminary investigation into the olfactory effects of essential oil concentrations on canine behavior

The positive impact of essential oils (EOs) on stress release has been demonstrated in both humans and dogs. Among the EOs known for their anxiety-reducing properties, including Cananga odorata, Citrus aurantium, Cupressus sempervirens, Lavandula angustifolia, and Litsea citrata, there is a lack of consensus on the optimal concentration for efficacy. This exploratory study sought to investigate the effects of olfactory enrichment with a blend of these EOs on dogs introduced to an unfamiliar environment. The authors sought to determine the minimum concentration required to achieve increased relaxation. In a randomized controlled crossover study design, 54 dogs were exposed to 0, 1, 5, and 10 drops of the EO blend applied to their collars before entering an unfamiliar room with their owners. Behavioral observations were employed to quantify the total duration of activity and relaxation related behaviours for each dog under each treatment condition. A significant difference in panting was identified among the treatments (χ2(3) = 9.88; p = 0.020). Dunn-Bonferroni post-hoc tests revealed a significant reduction in panting during the 10 drops treatment compared to the control treatment (p = 0.047). No significant differences were observed for other behaviors. To provide a comprehensive overview of behavioral tendencies in this canine population, owners also completed the Canine Behavioral Assessment and Research Questionnaire (C-BARQ), revealing low scores for anxiety in the study group. These preliminary findings suggest that a concentration of 10 drops of the EO blend on a dog's collar induces increased relaxation, specifically reflected in decreased panting behavior. Lower concentrations did not exhibit a significant relationship with the observed behaviors. These initial findings underscore the importance of exposing dogs to an appropriate concentration of EOs when exploring their potential benefits on welfare among dogs with low anxiety levels. Further research in this area is crucial for a comprehensive understanding of the potential benefits of EOs for canine welfare.

Beware of Strangers: Dogs' Empathetic Response to Unknown Humans

Empathy is a complex cognitive ability that has been studied in many social animals, including dogs. Previous studies have found that dogs would rescue their distressed owner more quickly than a calm owner and that dogs respond physiologically and behaviorally to the sound of crying strangers. However, no studies have explored the empathetic and emotional contagion capabilities of dogs towards strangers in rescue paradigms. In the present study, a stranger was placed behind a clear door and was told to cry (distress) or hum (neutral). The dogs' door opening, stress behaviors, tone of approach, and physiological responses were measured. Dogs did not open more frequently or more quickly for the stranger in the distressed condition compared to the neutral condition. Additionally, there was no significant difference between the behavioral or physiological indicators of stress across conditions. It was also found that non-openers were reported by owners to have more fear and, in the empathy test, were more aggressive and fearful in their tone of approach. These results suggest that dogs may be less likely to exhibit empathy-like behaviors to unknown humans in an unfamiliar environment and that owners may be necessary to moderate a dog's stress to show empathetic behaviors.

Effects of single- or pair-housing on the welfare of shelter dogs: Behavioral and physiological indicators

Dogs are often housed alone in shelter settings to reduce injury and disease spread. However, social isolation can be a stressor for dogs. Prior studies have suggested that cohousing can produce behavioral and physiological benefits. These studies have typically focused on laboratory dogs or shelter dogs that have been kenneled for several months. Thus, those results might not necessarily generalize to shelter dogs, many of which have shorter lengths of stay than those dogs studied to date, and might be cohoused soon after intake. In fact, being pair-housed could, in the short term, be more stressful as dogs have to navigate novel social situations in small spaces. We investigated the behavioral and physiological effects of single- or pair-housing shelter dogs, most of which had recently entered the shelter. We collected behavioral data on 61 dogs (30 single-housed; 31 pair-housed) daily across seven days; we also collected urine for cortisol:creatinine analysis on a subset (22 single-housed; 18 pair-housed) for eight days (each day of the seven-day study plus a baseline sample on Day 0, prior to dogs' enrollment). We found pair-housed dogs engaged in three stress-related behaviors (lip licking, whining, and ears back) significantly less frequently than single-housed dogs. When we analyzed the change in urinary cortisol:creatinine (Days 1-7 values minus Day 0 value), we found that pair-housed dogs generally showed a greater decrease in cortisol:creatinine levels than single-housed dogs. Pair-housed dogs also had significantly shorter lengths of stay, but we did not detect any effect on dog-dog skills. Overall, we found well-matched pair-housing can have both proximate and ultimate welfare benefits for shelter dogs.

Asian elephant calf physiology and mahout perspectives during taming in Myanmar

A quarter of Asian elephants are captive, with greater than 90% of these tamed and cared for by handlers (mahouts) in Asia. Although taming is a much-discussed welfare issue, no studies to our knowledge have empirically assessed its impact on calves, and dialogue surrounding taming often lacks perspectives of those involved. Here, we interviewed mahouts involved in taming and monitored five physiological measures (faecal glucocorticoid metabolites (FGMs), serum cortisol, glucose, creatine kinase (CK) and heterophil:lymphocyte (H:L)) over the first 10 days of taming and following six months in 41 calves undergoing taming and 16 control individuals. These measures assess the duration and intensity of stress during taming. Interviews suggested mahouts had major concerns for their safety when discussing changing taming practices, an important consideration for future management. Calf physiological measures were elevated by 50-70% (FGMs/cortisol/glucose), 135% (H:L) and greater than 500% (CK) over the first few days of taming, indicative of elevated stress, not seen to the same extent in control adults. Some measures stabilized sooner (glucose/cortisol/CK/FGM: 7-10 days) than others (H:L: one-two months), indicating mostly acute stress. Our findings inform the welfare of approximately 15 000 captive elephants around the world. Future studies should compare taming in different populations and consider calf and mahout welfare.

Evaluation of indicators of acute emotional states in dogs

A complete assessment of animal welfare requires not just an understanding of negative emotional states, such as fear and anxiety, but also of positive states, such as calmness and happiness. However, few studies have identified accurate and reliable indicators of positive emotional states in dogs. This study aimed to identify parameters that may serve as indicators of short-term emotional states in dogs. Using a cross-over design, 60 dogs living at a research facility were exposed to six different 10-min scenarios expected to elicit responses varying in emotional valence and arousal. A range of behavioural and physiological parameters were collected and their relationship to anticipated emotional valence and arousal was analysed using linear and logistic mixed models. Cortisol, adrenocorticotropic hormone, heart rate variability, panting, whining, and body shake all demonstrated significant differences based on arousal levels, but only within negative valence scenarios. Scores from a qualitative behavioural assessment (QBA) were associated with both emotional valence and arousal and were considered the best indicator of positive valence. Activity, ear temperature, and sitting were associated with positive high arousal, although this may have been influenced by differing levels of movement induced during these scenarios. Meanwhile, heart rate, secretory immunoglobulin A, standing and lying all showed similar changes associated with arousal for both positive and negative valence scenarios. This study provides a critical first step towards identifying evidence-based indicators of short-term emotional states in dogs, while highlighting considerations that should be made when employing these parameters, including the influence of coder bias, food provision, exercise, and external temperature. Overall, it is recommended future dog emotion and welfare research use a combination of parameters including indicators of both emotional valence and arousal.

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

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

Why do dogs wag their tails?

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

Impact of Visual Barrier Removal on the Behavior of Shelter-Housed Dogs

With millions of dogs housed in shelters each year, it is important to consider how the shelter environment impacts welfare. Social isolation and a lack of control over the environment can negatively impact wellbeing. However, providing social opportunities requires costly resources and can raise concerns about increased barking. In this study, 17 dogs were observed before, during, and after a visual barrier was partially removed to increase the ability to see to other dogs and the surrounding room. Stress behaviors, crate position, and resting behaviors did not differ significantly across phases; however, vocalizations were lower in the visual access and post phases (Friedman's test, p = .02). In addition, in-room barking data (N = 66) revealed no change in barking duration when barriers were removed. This absence of an increase in vocalizations should alleviate some concerns with allowing visual social contact. However, the lack of impact on stress and resting behaviors may indicate that visual social contact alone is insufficient for providing significant welfare benefits and that shelters should prioritize increasing social contact through playgroups or group housing.

The Adaptation of Maslow's Hierarchy of Needs to the Hierarchy of Dogs' Needs Using a Consensus Building Approach

It is crucial for good dog welfare that humans be able to accurately and adequately recognize and meet dogs' needs. However, humans may do a poor job of recognizing dogs' needs due to their tendency to anthropomorphize. The aim of this study was to develop a framework for dogs' needs that would help humans to recognize and meet their actual needs, thereby improving dogs' quality of life. Using the Delphi method, to reach as close to a consensus as possible from an expert panel, Maslow's Hierarchy of Needs was adapted to become the Dogs' Hierarchy of Needs. To do so, the relevant scientific literature was reviewed to identify 37 specific dog needs, which were group into seven need groups. Those groups were then organized onto five need levels, which were as analogous to Maslow's Hierarchy of Needs as possible. The expert panel was asked to assess various aspects of the adapted hierarchy in comparison to the original, including face validity, whether they agreed with how the need levels were ordered in terms of importance/priority, and whether they felt that any need groups should be more or less prioritized for any specific dog categories (e.g., senior dogs). After three rounds of expert feedback, there was sufficient consensus for all aspects except items pertaining to the prioritization of any need groups for specific dog categories. That aspect of the adapted hierarchy will need to be readdressed in the next phase of this project: the development of a tool to assess the quality of life of dogs that reside in shelters/rescue organizations and post-adoption once they have been rehomed.

Sensor-supported measurement of adaptability of dogs (Canis familiaris) to a shelter environment: Nocturnal activity and behavior

Every shelter dog is faced with the challenge to adapt to a kennel environment. To monitor the welfare of individual shelter dogs, evaluating behavioural and physiological parameters, potentially useful as indicators for adaptability of individual dogs is crucial. Nocturnal activity, i.e. resting patterns, has already been identified as a candidate indicator of adaptability and can be easily measured remotely with the help of sensors. We investigated the usefulness of a 3-axial accelerometer (Actigraph®) to monitor nocturnal activity in shelter dogs every night during the full first two weeks in-shelter starting directly at shelter intake, as a measure of welfare. Additionally, urinary cortisol/creatinine ratio (UCCR), body weight and behaviour data were collected to evaluate stress responses. A control group of pet dogs in homes, matched to the shelter dog group, was also monitored. Shelter dogs had higher nocturnal activity and UCCRs than pet dogs, especially during the first days in the shelter. Nocturnal activity, both accelerometer measures and activity behaviour, and UCCRs decreased over nights in the shelter. Smaller dogs had higher nocturnal activity and UCCRs than larger dogs and showed less autogrooming during the first nights. Dogs with no previous kennel experience had higher nocturnal activity and UCCRs, and showed less body shaking, than dogs with previous kennel experience. Overall, sheltered dogs also showed less body shaking during the first night. The number of dogs showing paw lifting decreased over days. Age class and sex effected only few activity behaviours. Shelter dogs significantly lost body weight after 12 days in the shelter compared to the moment of intake. Shelter dogs had disrupted nocturnal resting patterns and UCCRs compared to pet dogs and seem to partly adapt to the shelter environment after two weeks. Sensor-supported identification of nocturnal activity can be a useful additional tool for welfare assessments in animal shelters.

The Science and Social Validity of Companion Animal Welfare: Functionally Defined Parameters in a Multidisciplinary Field

Social validity refers to the social significance and acceptability of intervention goals, procedures, and outcomes. Animal practitioners, who are often guided by the principles of ABA, lack the benefit of verbal participants (at least with respect to target animals) with which to assess a client's needs and preferences. The study of a learner's welfare is useful for determining areas where intervention is needed or how the learner feels about an intervention that is underway. Three tenets of animal welfare measurement include physiological function, naturalistic behavior, and affect, where affect refers to private events, including emotions, which are a function of the same variables and contingencies responsible for controlling public behavior. The development of new technologies allows us to look "under the skin" and account for subjective experiences that can now be observed objectively. We introduce the reader to tools available from the animal welfare sciences for the objective measurement of social validity from the learner's perspective.

Understanding the Role of Therapy Dogs in Human Health Promotion

Dogs may provide humans with a range of physical, mental and social benefits. Whilst there is growing scientific evidence of benefits to humans, there has been less focus on the impact to canine health, welfare and ethical considerations for the dogs. The importance of animal welfare is increasingly acknowledged, indicating that the Ottawa Charter should be extended to include the welfare of non-human animals supporting the promotion of human health. Therapy dog programmes are delivered across a variety of settings including hospitals, aged care facilities and mental health services, highlighting the important role they play in human health outcomes. Research has shown that that there are biomarkers for stress in humans and other animals engaged in human-animal interactions. This review aims to assess the impact of human-animal interactions on therapy dogs engaged in providing support to human health. While challenging, it is paramount to ensure that, within the framework of One Welfare, the welfare of therapy dogs is included, as it is a key factor for future sustainability. We identified a range of concerns due to the lack of guidelines and standards to protect the wellbeing of the dogs engaged in these programmes. Extension of the Ottawa Charter to include the welfare of non-human animals with leveraging through a One Welfare approach would promote animal and human health beyond current boundaries.

Premedication with acetazolamide: Is its use for postoperative pain and stress control after laparoscopic ovariectomy in dogs ruled out?

BACKGROUND

Studies in human medicine have concluded that acetazolamide reduces pain associated with carbon dioxide insufflation during laparoscopic surgery. However, there are no published reports regarding the use of acetazolamide for this purpose in companion animals, despite the increasing popularity of laparoscopic techniques in veterinary medicine due to their advantages over open surgeries.

OBJECTIVES

Thirty mixed-breed female dogs were included in the study and randomly assigned to one of three groups: OVE (median celiotomy ovariectomy; n = 10), OVEL (laparoscopic ovariectomy, n = 10) and OVELA (laparoscopic ovariectomy with acetazolamide preoperative administration; n = 10). Experienced surgeons performed all procedures, and the anaesthetic and analgesic protocols were identical for all animals. Acetazolamide was administered orally (at a dose of 25 mg/kg) 2 h prior to induction in the OVELA group. Postoperative pain was evaluated using serum cortisol, salivary cortisol, and the University of Melbourne Pain Scale (UMPS) Score.

RESULTS

Any statistical differences were observed in the UMPS scores when the OVELA group was compared to the OVEL group at 1 h after surgery (p = 0.515), 12 h (p = 0.375) and 24 h (p = 0.242). Animals undergoing open surgery (OVE group) had significantly higher pain scores at all times after surgery when compared with OVEL and OVELA groups. A high positive correlation (r = 0.792; p = 0.01) was found between serum and saliva cortisol concentrations. Mean saliva cortisol concentration was not significantly lower for the OVELA group compared to the other groups.

CONCLUSIONS

This study found evidence that preoperative administration of acetazolamide may be beneficial in managing postoperative pain in dogs after laparoscopic surgeries. However, further research with a larger sample size is needed to confirm this and to determine if acetazolamide should be included in a multimodal postoperative analgesia protocol for laparoscopic ovariectomy in dogs.

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.

Current Perspectives on the Challenges of Implementing Assistance Dogs in Human Mental Health Care

The prevalence of mental health disorders, driven by current global crises, is notably high. During the past decades, the popularity of dogs assisting humans with a wide spectrum of mental health disorders has significantly increased. Notwithstanding these dogs' doubtless value, research on their legal status, certification processes, training and management practices, as well as their welfare status, has been scarce. This scoping review highlights that in contrast to other assistance dogs such as guide dogs, there exists no consistent terminology to mark dogs that assist humans with impaired mental health. Legal authorities monitoring the accreditation process, training and tracking of mental health supporting dogs are broadly lacking, with only few exceptions. This review emphasizes the need to address several topics in the promotion of progress in legal and welfare issues related to assistance dogs as well as emotional support dogs for humans with a mental health disorder. The current body of knowledge was assessed in three different areas of focus: (1) the legal dimension including definitions and certification processes; (2) the dimension of performed tasks; and (3) the dog welfare dimension including aspects of the relationship with the handler and risks associated with children recipients. Considering the challenges associated with a mental health diagnosis, collaborations of dog provider organizations and health care professionals would be desirable to continuously assess the efficiency of the human-dog dyad regarding their overall compatibility, general satisfaction and mutual well-being.

Bonded by nature: Humans form equally strong and reciprocated bonds with similar raised dogs and wolves

Introduction

To explore human-canid relationships, we tested similarly socialized and raised dogs (Canis familiaris) and wolves (Canis lupus) and their trainers in a wildlife park. The aims of our study were twofold: first, we aimed to test which factors influenced the relationships that the trainers formed with the dogs or wolves and second, we investigated if the animals reacted to the trainers in accordance with the trainers' perceptions of their relationship.

Methods

To achieve these goals, we assessed the relationships using a human-animal bonds survey, which the trainers used to rate the bonds between themselves and their peers with the canids, and by observing dyadic trainer-canid social interactions.

Results

Our preliminary results given the small sample size and the set-up of the research center, demonstrate that our survey was a valid way to measure these bonds since trainers seem to perceive and agree on the strength of their bonds with the animals and that of their fellow trainers. Moreover, the strength of the bond as perceived by the trainers was mainly predicted by whether or not the trainer was a hand-raiser of the specific animal, but not by whether or not the animal was a wolf or a dog. In the interaction test, we found that male animals and animals the trainers felt more bonded to, spent more time in proximity of and in contact with the trainers; there was no difference based on species.

Discussion

These results support the hypothesis that wolves, similarly to dogs, can form close relationships with familiar humans when highly socialized (Canine Cooperation Hypothesis). Moreover, as in other studies, dogs showed more submissive behaviors than wolves and did so more with experienced than less experienced trainers. Our study suggests that humans and canines form differentiated bonds with each other that, if close, are independent of whether the animal is a wolf or dog.

The Effect of Transportation on Puppy Welfare from Commercial Breeding Kennels to a Distributor

Many puppies from commercial breeding kennels (CBKs) are transported by ground from their kennels of origin to a distributor. This experience may elicit fear and stress during a sensitive developmental period, which may in turn negatively impact the puppies’ short- and long-term welfare. This study aimed to measure short-term effects of transportation on puppy welfare metrics. Eight-week-old puppies (n = 383) from 12 CBKs were tested at their kennels (pre-trans) and ~48 h after arriving at a distributor (post-trans). At each location, puppies underwent an isolation test, a stranger-approach test, and a physical health assessment. Behavioral responses to testing were scored from videos. Fecal glucocorticoid metabolites (FGM), fecal secretory immunoglobulin A (sIgA), and presence of intestinal parasites were also analyzed. Linear mixed-effects models identified decreased exploration (p < 0.001), and increased locomotion (p < 0.001) and escape attempts (p = 0.001) during the post-trans isolation test. Increased affiliative behavior (p < 0.001), FGM (p < 0.001) and sIgA (p = 0.014) were also observed post-trans. Findings support good physical health both pre- and post-trans, while behavioral and physiological changes suggest increased puppy distress post-trans. Higher post-transport affiliative behavior may indicate that puppies sought social support as a coping strategy after experiencing transport-related distress. Future studies should explore the efficacy of transportation-related interventions to mitigate puppy distress.

Comparing Pears to Apples: Unlike Dogs, Cats Need Habituation before Lab Tests

Simple Summary

Comparative studies can help us better understand our family pets’ social and cognitive behaviours and gain more insights in the evolution of some human abilities. However, the comparison of the behaviours of cats and dogs in a standard laboratory environment is not without challenges. Though recently they play a similar role in modern Western societies as pets, both their evolutionary history and individual experiences are different. We tested the spontaneous behaviour of companion cats and dogs in the same novel laboratory environment, and if needed, we tried to habituate them in the presence of their owners and an unfamiliar experimenter. To pass the habituation test, subjects were expected to play with the experimenter or accept food from them. All dogs passed the test on the first occasion, while almost 60% of the cats needed habituation and some could not reach the criteria even after three habituation sessions. More experienced cats (which had the opportunity to meet strangers and explore unfamiliar places) were not more successful, in fact, younger cats passed more easily. We found marked differences between dogs and cats in all behavioural variables; compared to dogs, cats spent more time crouching and close to their box, while less time exploring or close to the owner. Our findings are important not only regarding the test methods of cats and the interpretation of their data collected in the laboratory so far but, in a more general sense, on developing future comparative experiments.

Abstract

Research on the socio-cognitive skills of different species often benefit from comparative experiments, however, the ecology of the species and development of the individuals may differently determine how they react to the same test situation. In this study, our aims were twofold: to observe and compare the spontaneous behaviour of companion cats and dogs in the same novel environment, and to habituate them (if needed) to the novel environment in the presence of their owners and an unfamiliar experimenter. The behaviour of 62 family cats, 31 experienced (which had the opportunity to meet strangers and explore unfamiliar places) and 31 inexperienced cats, and 27 family dogs was compared in an unfamiliar room. The subjects’ behaviour was coded during the first five minutes in the presence of two passive persons, their owners, and an unfamiliar experimenter. Then, based on a set of rules, first the owner, and then the experimenter tried to initiate interactions with the subjects and the subjects’ willingness to interact was evaluated. To pass the habituation test, subjects were expected to play with the experimenter or accept food from them. All dogs passed the test on the first occasion, while almost 60% of the cats failed. The cats’ experience did not play a significant role, in fact, younger cats passed more easily. We found marked differences between dogs and cats in all behavioural variables; compared to dogs, cats spent more time crouching and close to their box, while less time exploring or close to the owner. We did not find a difference in the cats’ behaviour based on their experience. Our results support the hypothesis that unlike dogs, cats need extensive habituation in a novel environment. This could partially be explained by the difference in the ecology and/or domestication process of the species, although developmental effects cannot be excluded. Our findings have fundamental consequences not only for the considerations of the testability of cats and on the interpretation of their data collected in the laboratory, but in a more general sense on developing comparative experiments.

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

Simple Summary

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

Abstract

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

Assessing the Relationship Between Emotional States of Dogs and Their Human Handlers, Using Simultaneous Behavioral and Cardiac Measures

Negative stress due to human handling has been reported for a number of domestic animals, including dogs. Many companion dogs display significant stress during routine care in the veterinary clinic, risking injury to staff and potentially compromising the quality of care that these dogs receive. On the other hand, positive interactions with humans can have a beneficial effect on dogs, particularly in stressful situations such as animal shelters. Research has shown that dogs can detect human emotions through visual, auditory, and chemical channels, and that dogs will exhibit emotional contagion, particularly with familiar humans. This study investigated relationships between emotional states of dogs and unfamiliar human handlers, using simultaneous measures of cardiac activity and behavior, during two sessions of three consecutive routine handling sets. Measures of cardiac activity included mean heart rate (HR_mean), and two measures of heart rate variability (HRV): the root mean square of successive differences between normal heartbeats (RMSSD); and the high frequency absolute power component of HRV, log transformed (HF_log). We also assessed human handlers' emotional state during handling sessions following an intervention designed to reduce stress, compared with sessions conducted on a different day and following a control activity. Polar H10 cardiac sensors were used to simultaneously record cardiac activity for both canine and human participants, and behavioral data were collected via digital video. The strongest influence on the dogs' stress levels in our study was found to be increasing familiarity with the setting and the handler; HR_mean and SI decreased, and HRV (as RMSSD) increased, significantly from the first to the third handling set. Canine HRV (as HF_log) was also highest in set 3, although the difference was not statistically significant. There were no strong patterns found in the human cardiac data across handling set, session, or by pre-handling activity. We did not find consistent support for emotional contagion between the dogs and their handlers in this study, perhaps due to the brief time that the dogs spent with the handlers. Recommendations for application to dog handling, and limitations of our methods, are described.

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.

Effects of trazodone on behavioral and physiological signs of stress in dogs during veterinary visits: a randomized double-blind placebo-controlled crossover clinical trial

OBJECTIVE

To determine whether a single dose of trazodone administered to dogs before a veterinary visit reduced their behavioral and physiologic signs of stress and owners' stress during veterinary visits.

SAMPLE

20 dogs and their owners.

PROCEDURES

In this randomized double-blinded placebo-controlled crossover clinical trial, dogs with a history of anxiety during veterinary visits were scheduled for 2 veterinary visits 1 week apart and randomly assigned to receive a single oral dose of either trazodone (9 to 12 mg/kg) or a placebo 90 minutes before transport to the veterinary clinic for alternate visits between September 21 and November 3, 2019. For each visit, we collected and assessed owner-completed surveys of dog stress score (DSS) and owner stress score; various investigator-reported scores, including from video-recorded behavior analyses; and patient-related physiologic data.

RESULTS

Dogs treated with trazodone versus placebo had lower mean DSSs, assessed by owners for physical examination and assessed by video analysis for time spent in the examination room; lower mean SD of normal-to-normal intervals, root mean square of successive heartbeat interval difference, and respiratory rate; and higher mean heart rate. No meaningful differences were observed in other behavioral or physiologic outcomes, including serum cortisol concentrations.

CLINICAL RELEVANCE

A single dose of trazodone before transport reduced signs of stress during veterinary visits for dogs in the present study and may be useful as an anti-anxiety medication for similarly affected dogs, potentially resulting in higher-quality clinical examinations and improved patient welfare.

Measuring salivary cortisol in wild carnivores

Salivary hormone analyses provide a useful alternative to fecal and urinary hormone analyses in non-invasive studies of behavioral endocrinology. Here, we use saliva to assess cortisol levels in a wild population of spotted hyenas (Crocuta crocuta), a gregarious carnivore living in complex social groups. We first describe a novel, non-invasive method of collecting saliva from juvenile hyenas and validate a salivary cortisol assay for use in this species. We then analyze over 260 saliva samples collected from nearly 70 juveniles to investigate the relationships between cortisol and temporal and social variables in these animals. We obtain some evidence of a bimodal daily rhythm with salivary cortisol concentrations dropping around dawn and dusk, times at which cub activity levels are changing substantially. We also find that dominant littermates have lower cortisol than singleton juveniles, but that cortisol does not vary with age, sex, or maternal social rank. Finally, we examine how social behaviors such as aggression or play affect salivary cortisol concentrations. We find that inflicting aggression on others was associated with lower cortisol concentrations. We hope that the detailed description of our methods provides wildlife researchers with the tools to measure salivary cortisol in other wild carnivores.

Effects of Positive Reinforcement Training and Novel Object Exposure on Salivary Cortisol Levels under Consideration of Individual Variation in Captive African Elephants (Loxodonta africana)

Simple Summary

Regular training for medical or enrichment purposes and the provision of environmental enrichment, such as varied feeding schedules and novel objects, are part of the management of African elephants in zoos. The present study aimed to find out whether training and enrichment in the form of a novel object induced physiological changes in captive African elephants. We repeatedly sampled the saliva of ten animals (three zoos) before and after training and the exposure to a novel object for the analysis of cortisol and as a measure of stress and arousal. We found high salivary cortisol levels before and low levels after training. A novel object, in contrast, moderately increased the salivary cortisol levels. Moreover, males and young elephants showed lower salivary cortisol levels than females and old elephants, respectively. The zoo, handling method (free vs. protected contact to keepers), reproductive and social status, however, did not influence the salivary cortisol levels of the animals studied. We conclude that the relatively high cortisol values before training could be due to anticipation of the training event. A novel object, in contrast, may have evoked arousal, which led to the observed cortisol increase. In addition, understanding why animals differ in stress responses will help to manage stress in zoo elephants with the goal of ensuring their welfare.

Abstract

Dealing with potential stress in species that have high husbandry requirements, such as elephants, is a challenge for zoos. The objective of the present study was to determine whether positive reinforcement training (PRT) and exposure to a novel object (NOV) for enrichment induced a salivary cortisol response indicative of activation of the hypothalamic–pituitary–adrenal (HPA) axis and which factors determine individual variation in this regard in captive African elephants. We repeatedly sampled the saliva of ten animals (three zoos) for the analysis of cortisol (SACort) before and up to 60 min (in 10–15 min intervals) after the onset of PRT (three repeats) or NOV (nine repeats), which lasted 10 min. There was considerable individual variation in SACort in response to PRT or NOV. Using mixed models, we were able to control these and to reveal that PRT was associated with high SACort before and relatively low SACort after PRT, while NOV induced a moderate SACort increase. The individual differences in SACort were related to age and sex (NOV), while the effects of zoo, handling method (free vs. protected contact) and reproductive and social status were variable. We conclude that positive affective states, such as anticipation or arousal, should be taken into account when interpreting the differences in the SACort responses between PRT and NOV. In addition, understanding the individuality of stress will support management decisions aimed at promoting captive elephant welfare.

Stress-Related Behaviors in Companion Dogs Exposed to Common Household Noises, and Owners' Interpretations of Their Dogs' Behaviors

Sudden, loud noises are one of the most common triggers for fearful behaviors in dogs, and many companion dogs suffer from noise sensitivity. Existing research focuses on dramatic infrequent sounds (e.g., thunderstorms, fireworks). Anecdotally, and based on reports of undesirable behaviors in response to noises in the home, many common household noises may also be causing fear and anxiety in companion dogs. However, these responses have not yet been studied in home environments. We surveyed 386 dog owners about their dogs' responses to household sounds, and recorded dog behaviors and human reactions from 62 videos and compilations available on an online video sharing platform, featuring dogs reacting to common household noises. Numerous signs of canine fear and anxiety were reported by survey respondents and observed in the videos, in response to both daily, and irregular but “normal,” household noises. Responses were significantly stronger to sounds characterized as high frequency intermittent than to sounds characterized as low frequency continuous. Respondents appeared to underestimate their dogs' fearfulness, and the majority of humans in the videos responded to their dogs' behaviors with amusement; welfare concerns were rarely expressed. While these videos cannot be used to calculate actual prevalence of these issues, our data support that some owners are underestimating fearfulness in their dogs in response to household noises, and responding inappropriately to dogs' expressions of fear and anxiety. Better education is required for dog owners to accurately interpret canine body language, to both safeguard dogs' welfare and minimize development of anxiety-related behavior problems.

Behavioural and Physiological Correlates of the Canine Frustration Questionnaire

Frustration is a negative emotional state implicated in a range of canine behaviour problems. The Canine Frustration Questionnaire (CFQ) is the first psychometric tool developed to assess frustration tendencies in dogs based on owner report. However, to date, no published studies have assessed behavioural and physiological correlates of this trait. A novel behaviour test battery was developed to induce frustration in dogs, mapping onto the CFQ. Forty-four dogs were recruited and filmed whilst undertaking the test battery, and a CFQ was completed by each owner. Targeted behavioural measures were assessed from this footage, based on hypotheses aimed at evaluating convergent and discriminant validity with facets of the CFQ. In addition, a saliva sample was collected pre- and post-testing for 39 dogs, and a cortisol assay performed using ELISA to provide a physiological measure of arousal. A range of predicted behavioural test measures (e.g., vocalising and lunging) positively correlated with CFQ scores. For 22 dogs with pre-test salivary cortisol levels of <4 ng/mL (indicative of normal arousal at baseline), cortisol change and post-test cortisol levels positively correlated with the CFQ PC5 'Frustration coping' score. These results provide further evidence of the validity of frustration tendencies as measured by owner report through the CFQ.

Laparoscopic Castration Using Bipolar Forceps vs. Orchiectomy in Dogs: A Comparison of Two Techniques

Simple Summary

Castration of dogs is one of the most often performed surgeries in veterinary medicine. Minimally invasive techniques used in human medicine are now being used in animals. We compared the feasibility and effects on pain and inflammation of a new laparoscopic technique with the classical castration technique. The animals in which the new technique was applied showed less pain and inflammation then the other group. Our results suggest that this is a feasible alternative to classical castration.

Abstract

This paper aimed to study the feasibility of a new laparoscopic castration technique in male dogs, evaluate the pain associated with it, and compare it with the classical orchiectomy. Surgical times, pain scores, blood and salivary cortisol, and CRP were recorded and compared between the two groups. The use of high-frequency bipolar forceps allowed quick and uneventful laparoscopic procedures. The laparoscopic group had significantly lower pain scores, cortisol, and PCR values than the orchiectomy group. No complications were seen in any group. Our results suggest that this laparoscopic castration is a safe and beneficial surgical alternative to traditional orchiectomy in dogs.

Salivary stress markers in dogs: Potential markers of acute stress

Along with the growing awareness of psychological stress in companion animals, several treatments have become available to address fear- and anxiety-related behaviors in dogs. To detect vulnerable individuals and apply effective treatments, reliable evaluations that can quantify individual stress responses are in high demand. To develop measurable variables that have clinical applications, more investigations are needed to increase our knowledge. When stress responses are activated by the sympathetic-adrenal-medullary (SAM) and hypothalamic-pituitary-adrenal (HPA) axes, the immune system is also activated. Although the peripheral cortisol level is commonly used as a stress biomarker, it primarily reflects the HPA axis response and does not sufficiently reflect the complexity of the stress response. Thus, this review primarily focuses on the available salivary biomarkers that mainly reflect the acute stress response through the activity of the SAM axis and the immune system in dogs. We hope that this review will promote the validation of these biomarkers in dogs and aid in the development of future studies to evaluate stress responses in dogs.

Use of Infrared Thermography during Ejaculation Process and Its Link with Semen Quality and Freezability in Dogs

Simple Summary

Scientific attention to infrared technology has grown over the last decade. Remote and non-invasive monitoring techniques are of great importance in discovering ejaculation response and future trends because of their role in vascular flux regulation. However, detailed information about its use in andrology has yet to be fully explained. Therefore, we aimed to reveal information about the amount of sperm to be obtained by observing stress levels with non-invasive eye temperature measurement, and the relationship between various reproductive temperature patterns and parameters of the animal’s various physiological conditions such as age, body condition, total ejaculation time and testicular volume.

Abstract

This study aimed to describe the thermal variation of external reproductive tracts during ejaculation in relation to sperm quality in dogs. Forty-six adult fertile dogs were monitored using a thermal camera before, during and after the semen collection, taking into account penile and scrotal temperatures as reproductive thermal patterns while eye and perianal temperatures were recorded as complementary thermal patterns of behavioral response. The parameters were classified depending on age (≤4 years and >4 years), body weight (BW) (≤75 kg and >75 kg), sperm concentration (CON) (≤300 million and >300 million), total testicular volume (TTV) (≤600 cm³ and >600 cm³) and total ejaculation time (TET) (≤800 s and >800 s) of the animals from which semen was collected successfully. Heavier males (p < 0.05) that have more consistent testicles (p < 0.01) as well as quicker ejaculate responders (p < 0.001) and lower scrotal temperature had better semen (Δ motility) freezability. The lower eye temperature prior to the ejaculation (p < 0.01), lower scrotal temperature following ejaculation (p < 0.01), and conversely, higher penile temperature during the ejaculation (p < 0.001) had a higher sperm concentration. Furthermore, the sperm freezability was negatively correlated with total ejaculation time (r = −0.39, p < 0.05) and sperm abnormalities were lower in the ejaculate of dogs having a higher temperature of the scrotum, bulbus and penis. In conclusion, infrared monitoring throughout semen collection in dogs can provide information on behavioral reactions during human manipulation, as well as semen quality and testicular functionality.

Dog Pulling on the Leash: Effects of Restraint by a Neck Collar vs. a Chest Harness

Leash pulling is a concern for dog owners and can be detrimental to the health and welfare of dogs. Neck-collars and back-connection harnesses are popular restraint types. Harnesses have been proposed as a better and more considerate option for canine health and welfare. Anecdotally, dogs pull more when wearing a back-connection harness; however, there is no scientific evidence for this perception. This study aimed to investigate how strongly dogs pull on the lead to achieve a food treat or toy under restraint by a neck-collar versus a back-connection harness. A within-subject counterbalanced design was used for the study, involving 52 shelter dogs. A customised canine leash tension metre was connected to the collar or harness to record the pulling of the dogs, including measuring the maximal and mean leash tension, and the time spent pulling. In addition, dog behaviours were recorded using two cameras from two separate directions. The maximal and mean leash tension and the pulling time were greater under restraint by harness when attracting dogs with food treats. No significant difference between harness and collar was found in potential stress-related behaviours (e.g. tail and ear positions, lip-licking, and panting). However, dogs looked at the experimenter more often when restrained by harness than collar in the food treat attraction test. No significant difference was detected between harness and collar with respect to leash tension and stress-related behaviours in the toy attraction test. These findings suggest that dogs tend to pull stronger and more steadily when wearing a back-connection harness compared to a neck collar to reach the food treat but not the toy.

Volunteers' Demographics That Affect the Human-Dog Interaction During Walks in a Shelter

Different people relate to dogs in different ways. We investigated differences between volunteers in their behavioural interactions with shelter dogs when they were walked on a leash. Cameras were used to record and quantify the behaviour of volunteers and a leash tension metre was used to measure pulling by both volunteers and shelter dogs. Effects of volunteers' age, body height, educational level, marital status, and experiences of living and working with dogs, and living with children, were examined. Older volunteers talked to the dogs more often during the walk than younger ones. Taller volunteers had reduced physical contact with dogs, and dogs pulled more frequently on the leash while walking with them. Volunteers with a postgraduate degree more frequently praised dogs and rewarded dogs with food and used more body language in the form of hand gestures and physical contact. Married and partnered volunteers more often praised dogs, while separated/divorced or widowed volunteers initiated more frequent physical contacts. Dogs pulled less when walking with volunteers who had experience of living with dogs, and these volunteers interacted with dogs using fewer verbal and body languages. Finally, those living with children more frequently communicated with dogs using body language (e.g., hand gestures and physical contact). We conclude that shelters should carefully consider volunteers' demographics when selecting them to walk dogs with various behavioural characteristics.

Effects of Interval Exercise Training on Serum Biochemistry and Bone Mineral Density in Dogs

Simple Summary

In this study, six male beagle dogs underwent 12 weeks of interval exercise following the Frequency, Intensity, Time/duration, Type, Volume, and Progression (FITT-VP) training principle. The heart rate (HR) response was measured during the entire exercise period, and changes in bone mineral density (BMD), muscle volume (MV), and hematology and serum biomarkers were evaluated at the pre-exercise training period and post-exercise training period. We showed that exercise training increased BMD in the femur and serum total alkaline phosphatase (TALP), aspartate aminotransferase, and creatine kinase levels. In addition, our data suggest a positive correlation between BMD and TALP, demonstrating that increased TALP might be an important contributing factor for enhancing BMD with physical training in dogs.

Abstract

Exercise has been suggested as a powerful intervention for health care and fitness management in humans; however, few studies have demonstrated the benefits of exercise training in dogs. The purpose of this study was to examine the effects of exercise training on heart rate (HR), bone mineral density (BMD), muscle volume (MV), and hematological and serum biomarkers in dogs. Six healthy beagles completed the interval treadmill exercise, developed on the basis of the FITT principle, two times a week for 12 weeks. To evaluate the physiological parameters, the HR values were analyzed using the Polar H10 system during the entire exercise period. At pre-and post-exercise, quantitative computed tomography and hematological and serum biochemical parameters were analyzed. The interval exercise resulted in a normal HR response and no adverse behavioral or physiological effects on the dogs. We showed that exercise improved BMD in the femur (541.6 ± 16.7 vs. 610.2 ± 27.8 HA, p < 0.01) and increased serum total alkaline phosphatase (TALP; 68.6 ± 9.2 vs. 81.3 ± 17.2, p < 0.01), aspartate aminotransferase (23.5 ± 1.0 vs. 33.5 ± 1.6, p < 0.01), and creatine kinase (114.8 ± 5.3 vs. 214.0 ± 20.8, p < 0.01) levels. There was a positive relationship between BMD and TALP (femur: r = 0.760, p = 0.004; vertebrae: r = 0.637; p = 0.025). Our findings suggest that interval exercise training is beneficial to increase BMD in the femur, and an increased TALP level would be a concomitant mechanism for enhancing BMD with exercise in dogs.

Heart rate as a measure of emotional arousal in evolutionary biology

How individuals interact with their environment and respond to changes is a key area of research in evolutionary biology. A physiological parameter that provides an instant proxy for the activation of the automatic nervous system, and can be measured relatively easily, is modulation of heart rate. Over the past four decades, heart rate has been used to assess emotional arousal in non-human animals in a variety of contexts, including social behaviour, animal cognition, animal welfare and animal personality. In this review, I summarize how measuring heart rate has provided new insights into how social animals cope with challenges in their environment. I assess the advantages and limitations of different technologies used to measure heart rate in this context, including wearable heart rate belts and implantable transmitters, and provide an overview of prospective research avenues using established and new technologies, with a special focus on implications for applied research on animal welfare. This article is part of the theme issue 'Measuring physiology in free-living animals (Part II)'.

Evaluation of an easy-to-use protocol for assessing behaviors of dogs retiring from commercial breeding kennels

Objective, reliable behavioral tests are needed to refine on-site welfare assessments of dogs housed at commercial breeding (CB) kennels and provide a basis to inform predictions of their behavior when retired from such kennels. This study tested the reliability, construct validity, and applicability of a protocol for the behavioral assessment of dogs from CB kennels that might be useful in comprehensive welfare assessments of this population. A sample of 447 dogs from 26 CB kennels in the Midwestern US were assessed in their pens. Responses to an approach test (performed on three consecutive days) and a behavioral reactivity test (e.g., traffic cone, toys, umbrella) were recorded. Results showed moderate to perfect (Kw = 0.51-1.00) inter-rater reliability between three independent observers. Approach test-retest analysis showed high correlation of approach test scores on days 1, 2 and 3 (r = 0.85, p<0.0001). Exploratory factor analysis extracted four main factors: Food Motivation (F1), Sociability (F2), Boldness (F3) (e.g., response to novel objects), and Responsiveness (F4) (e.g., response to an umbrella opening) confirming the ability of the test to measure behaviors of interest. All factors showed high internal consistency (Cronbach's alpha 0.81-0.93) further supporting the robustness of the test construct. The demonstrated reliability of this protocol suggests that it may be usefully applied to assessing the behavior of dogs as a component of their welfare assessment in CB kennels. Doing so using even larger sample sizes may yield insights on the effects of housing and management practices on dog welfare while at the kennels, which may also help inform approaches that improve rehoming outcomes for retiring breeding dogs. Practical applications and limitations are outlined.

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.