Using hypothalamic–pituitary–adrenal measures for assessing and reducing the stress of dogs in shelters: A review

Serum total antioxidant status in dogs: Reference intervals and influence of multiple biological and analytical factors

BACKGROUND

Total antioxidant status (TAS) is one of the most widely used oxidative stress biomarkers, but the lack of canine RI and the influence of analytical factors hinder its application in clinical practice.

OBJECTIVES

The aims of this study were to establish canine assay-specific RI for TAS and evaluate the sources of biological variation and the association between TAS and multiple hematologic and biochemical variables.

METHODS

Blood samples from 190 clinically healthy dogs were collected, encompassing pet dogs (82), police dogs (56), and shelter dogs (52). After hematologic and biochemical analysis, serum TAS was determined by means of a commercial 2,2'-azinobis (3-ethylbenzthiazolin-6-sulfonic acid) (ABTS) test. The American Society for Veterinary Clinical Pathology guidelines were followed to establish the RI, employing nonparametric methods. Univariate analysis and multivariate analysis were conducted to assess the influence of biological and analytical variables, yielding a final regression model.

RESULTS

The final reference population comprised 143 dogs, for which the RI was established (1.41-2.27 mmol/L). Partitioning was applied to the three study groups. The regression model revealed that police dogs had significantly higher TAS values than pet dogs. Furthermore, significant associations between four biochemical variables (albumin, globulins, cholesterol, and aspartate aminotransferase) and serum TAS were found.

CONCLUSIONS

This is the first study to establish RI for serum TAS in a large and heterogeneous canine population and provide data on its relationship with analytical variables. These findings could potentially improve the interpretation of TAS in clinical environments.

Salivary cortisol measurements in brachycephalic dog breeds as part of a standardized stress test

Introduction

Brachycephalic obstructive airway syndrome (BOAS) is a common condition in brachycephalic dogs, with Pugs (PG) and French Bulldogs (FB) appearing to be particularly typically affected. Objective and easy-to-perform tests are necessary to detect the disease at an early stage and to exclude dogs affected by BOAS from breeding.

Methods

The present study investigated the extent to which vital signs and salivary cortisol concentrations can be used to distinguish between healthy and BOAS-affected dogs in a standardized fitness test. A total of 57 PG, 56 FB and 27 meso- and dolichocephalic dogs were studied as control group (CG). In addition to vital signs, salivary cortisol concentrations were measured before and after the exercise test.

Results

It emerged that non-brachycephalic dogs showed a higher fitness level than brachycephalic dogs. The PG recovered significantly slower than the FB after the exercise test. In unaffected PG, cortisol levels rose significantly after the test and then fell again, in unaffected FB they fell significantly during the test. Unexpectedly, cortisol levels remained constant in BOAS affected dogs of both breeds.

Discussion

A possible explanation could be a disturbance of the pituitary-hypothalamic-adrenal axis, which could be due to the chronic stress of affected animals. This would have to be clarified in further studies. In conclusion, a submaximal fitness test may be a useful method to identify dogs suffering from BOAS as it is imperative to prevent the breeding and reproduction of affected dogs.

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.

Going to the office - What's in it for the dog?

Benefits and challenges of dogs being present at the office were analyzed from three perspectives: the company view, the dog owner (employee) and the dog view. For companies, office dogs may serve as a branding symbol, leading to higher employee satisfaction and productivity, increased stress resilience and fewer turnover intentions. Yet, companies need to apply pet policies, risk management strategies and mitigate nuisance such as barking, loose fur or excrement. Additional breaks to walk the dogs are required and other employees or customers may be irritated. Employees take advantage of stress reduction, social support, higher job satisfaction, not having to leave their animal at home. Still, an office dog is an added responsibility in terms well-being, safety, distraction from work and emotional involvement. Although the animal perspective has not yet been scientifically addressed, we propose potential benefits such as less separation distress by having the owner nearby, higher social engagement and additional walks during breaks. Challenges for dogs may involve unwanted attention, aversive environmental stimulation, being restrained via leash or crate, irritation caused by conspecifics, emotional contagion or individual requirements.

Ruff Morning? The Use of Environmental Enrichment during an Acute Stressor in Kenneled Shelter Dogs

The length of stay for some animals has increased with the recent reduction of animals euthanized in US shelters and animal control facilities. Research examining the effectiveness of different types of enrichment on buffering the effects of acute daily stressors in the shelter environment, such as kennel cleaning, is lacking. In addition, daily known stressors can result in undesirable behaviors that could lead to a need for euthanasia. Ways to effectively reduce the effects of daily stressors while optimizing strained resources is currently a high priority. In this study, we presented shelter dogs with food, tactile, and scent enrichment items to increase (arousing) or decrease (calming) activity during the daily stressor of morning kennel cleaning. We found that calming, rather than arousing, enrichment items were associated with body position scores indicative of lower stress in dogs, with calming scent enrichment (lavender) producing the most significant benefit. In contrast, items that showed the greatest reduction in vocalization were arousing (ball) compared to other arousing conditions. Our findings suggest that different unwanted behaviors in the kennel environment often associated with stress can be reduced using specific types of enrichment during a daily stressful event. Further, the results illustrate that enrichment items other than food might be more effective at decreasing certain undesirable behaviors. Overall, this study provides insight into how shelter workers might effectively use enrichment items during an unavoidable acute stressor. With many shelters keeping dogs longer, addressing events that might cause repeated stress in this population may indirectly help with adopting and lowering euthanasia rates due to unwanted behavior that develops due to repeated exposure to this necessary but acute stressor of morning cleaning.

Assessment of Stress Caused by Environmental Changes for Improving the Welfare of Laboratory Beagle Dogs

Animal stress is influenced by environmental factors, yet only a few studies have evaluated the effects of environmental stress on captive dogs. This study aimed to evaluate the effects of environmental and social enrichment on the stress levels of captive dogs housed in a lab. We assessed stress levels in eight Beagle dogs by measuring their body weight, cortisol levels, a stress hormone, the alkaline phosphatase activity in serum, the number of steps per hour, as well as clinical sign observations in a changed environment for 6 weeks. Four dogs assigned to a control group were raised alone in a relatively narrow place without toys; four dogs assigned to an experimental group were raised together in a relatively large place with toys. The body weight of the control group remained unchanged, while that of the experimental group decreased. Cortisol levels in the control group increased throughout, whereas those in the experimental group increased for up to 2 weeks and decreased thereafter. Consequently, cortisol levels in the experimental group significantly decreased compared to the control group at 6 weeks (p = 0.048). Fighting was observed among the dogs in the experimental group at 3 weeks; thus, one dog was separated from the group. The number of steps per hour was more than twice as high in the experimental than in the control group. Thereby, we determined that social housing, with appropriate companions and environmental enrichment materials, can reduce stress levels in captive dogs more efficiently than in single housing without such materials. Our study provides useful insights for captive animal organizations, such as kenneled dogs' management, to improve animal welfare.

A single dose of cannabidiol (CBD) positively influences measures of stress in dogs during separation and car travel

Many dogs experience stress when separated from their caregivers, as well as when traveling in vehicles. Pet owners employ various approaches to managing these issues, from training, to giving medications and supplements, often with mixed results. Cannabidiol (CBD) can alleviate stress and anxiety in humans but the effect it has on canine stress is less well-documented. The present study aimed to understand the impact of being left alone and traveling in a car on measures of canine stress, and establish whether a single dose of a tetrahydrocannabinol (THC)-free CBD distillate could positively influence any measures of stress. In a blinded, parallel design study, a population of dogs were either left alone in a familiar room (n = 21) or underwent a short car journey (n = 19). A range of physiological and behavioral measures were collected pre, during and post-test. Significant changes in several stress-related measures (serum cortisol, mean ear temperature, heart rate, heart rate variability, whining and a stressed/anxious behavioral factor) were observed from baseline to test, with the car journey test paradigm eliciting a more pronounced stress response overall. The mitigating effect of CBD treatment varied by measure and test, with some indicating a significant reduction in canine stress compared to the placebo group. Additional research is required to fully understand the complex effect of CBD on canine wellbeing.

Using a Delphi method to estimate the relevance of indicators for the assessment of shelter dog welfare

The European regulatory framework lacks standardisation as regards the minimum requirements for shelter facilities, making defining welfare standards for dogs challenging. Dog (Canis familiaris) welfare assessments should consist of a comprehensive set of measurements that allow the calculation of an overall 'welfare score.' The Shelter Quality protocol was developed for the purpose of assessing shelter dog welfare. The study aims to establish a standardised system for evaluating shelter dog welfare by obtaining agreement from experts on the weighting of different measures contributing to an overall welfare score. The Delphi technique is a widely used method for establishing consensus among experts. Two Delphi procedures were implemented and we compared their effectiveness in achieving expert consensus by evaluating rounds' numbers required to reach consensus and the response and attrition rates. Expert consensus was achieved in Delphi 1 when the standard deviation in the expert weightings was ≤ 5. This was achieved easily for the welfare score weightings of the four principles: 'Good feeding', 'Good housing', 'Good Health', and 'Appropriate behaviour.' Animal-based measures were found to reach consensus more quickly than resource-based measures. In Delphi 2, we used the coefficient of variation to determine consensus. No statistical differences were found between the two Delphi methods for attrition rate, response rate or number of participants. Continuing rounds until a consensus is reached is recommended as this method balances time and participant fatigue. A standardised scoring system is provided, using a single overall score of welfare that can be used to compare welfare standards between shelters.

Behavioral Changes of Brown Bears (Ursus arctos) during COVID-19 Zoo Closures and Further Reopening to the Public

Visitor effect studies have been of keen interest for decades, but there have been only anecdotal opportunities to investigate the impact of the prolonged absence of visitors on animal welfare in zoos. In some zoos, bears are actively involved in animal–visitors interaction through begging, which gives them some degree of control over gaining food rewards throughout the day when visitors are present. Prolonged visitor absence may, therefore, represent a loss of control and have a negative impact on the bears’ welfare. In this study, we investigate the behavior of four brown bears (Ursus arctos) in three zoos to see how the animals’ behavior changed depending on the presence and absence of the public during zoo closures in 2020 related to the COVID-19 pandemic. The bears’ behavior was assessed using activity budget analysis and novel object tests. The results showed that the bears behavior varied between facilities and that there was no effect of visitor presence for the individuals who had access to indoor holding space. The results of the study are discussed in terms of choice and control and their impact on the wellbeing of bears in zoos.

Evaluation of shelter dog activity levels before and during COVID-19 using automated analysis

Animal shelters have been found to represent stressful environments for pet dogs, both affecting behavior and influencing welfare. The current COVID-19 pandemic has brought to light new uncertainties in animal sheltering practices which may affect shelter dog behavior in unexpected ways. To evaluate this, we analyzed changes in dog activity levels before COVID-19 and during COVID-19 using an automated video analysis within a large, open-admission animal shelter in New York City, USA. Shelter dog activity was analyzed during two two-week long time periods: (i) just before COVID-19 safety measures were put in place (Feb 26-Mar 17, 2020) and (ii) during the COVID-19 quarantine (July 10-23, 2020). During these two periods, video clips of 15.3 second, on average, were taken of participating kennels every hour from approximately 8 am to 8 pm. Using a two-step filtering approach, a matched sample (based on the number of days of observation) of 34 dogs was defined, consisting of 17 dogs in each group (N1/N2 = 17). An automated video analysis of active/non-active behaviors was conducted and compared to manual coding of activity. The automated analysis validated by comparison to manual coding reaching above 79% accuracy. Significant differences in the patterns of shelter dog activity were observed: less activity was observed in the afternoons before COVID-19 restrictions, while during COVID-19, activity remained at a constant average. Together, these findings suggest that 1) COVID-19 lockdown altered shelter dog in-kennel activity, likely due to changes in the shelter environment and 2) automated analysis can be used as a hands-off tool to monitor activity. While this method of analysis presents immense opportunity for future research, we discuss the limitations of automated analysis and guidelines in the context of shelter dogs that can increase accuracy of detection, as well as reflect on policy changes that might be helpful in mediating canine stress in changing shelter environments.

Emergency Fostering of Dogs From Animal Shelters During the COVID-19 Pandemic: Shelter Practices, Foster Caregiver Engagement, and Dog Outcomes

Each year, millions of dogs enter thousands of animal shelters across the United States. Life in the shelter can be stressful, and one type of intervention that improves dogs' experience is human interaction, particularly stays in foster homes. Prior research has demonstrated that fostering can reduce dogs' cortisol and increase their resting activity. Despite these benefits, little is understood about the utilization of foster caregiving in animal shelters, and even less so during a crisis. On March 11, 2020, the World Health Organization deemed the coronavirus outbreak a worldwide pandemic, and subsequently a nationwide emergency was declared in the United States. Nearly all states issued stay-at-home orders to curb the spread of the virus. During this time, media outlets reported increased interest in the adoption and fostering of shelter pets. This study explores canine foster caregiving at 19 US animal shelters during the first 4 months of the COVID-19 pandemic. In our investigation, we found that shelters' utilization of foster caregiving increased from March to April 2020 but returned to initial pandemic levels by June 2020. Slightly less than two-fifths of foster caregivers were community members with no prior relationship with the shelter, and these caregivers were over four times more likely to adopt their fostered dogs than those with a pre-existing relationship to the shelter. Individuals fostering with the intention to adopt, in fact, adopted their dogs in nearly three-quarters of those instances. With regards to shelters' available resources, we found that very low-resource shelters relied more heavily on individuals with prior relationships to provide foster caregiving while very high-resource shelters more often recruited new community members. We also found that our lowest resourced shelters transferred more dogs out of their facilities while more resourced shelters rehomed dogs directly to adopters. To our knowledge, these findings represent the first in-depth reporting about dog fostering in US animal shelters and, more specifically, foster caregiving during the COVID-19 pandemic. In total, they provide greater understanding of how monetary and human resources were utilized to affect the care and ultimately, the outcomes of shelter dogs during this time.

Evaluation of hair cortisol as an indicator of long-term stress responses in dogs in an animal shelter and after subsequent adoption

Shelter dogs are exposed to a variety of stressors. Among non-invasive techniques, hair cortisol concentration (HCC) is suggested an easy to collect biomarker for giving insight into long-term stress responses. We evaluated HCC as an indicator of long-term cortisol responses in dogs in an animal shelter over different chronological time points during sheltering and after adoption. Hair samples were collected from the neck region following a shave/re-shave protocol of shelter dogs (total n = 52) at four different time periods: T1 intake at shelter (pre-shelter period, n = 51); T2 after 6 weeks in the shelter (n = 23); T3 6 weeks after adoption (n = 24); T4 6 months after adoption (n = 22). HCC at T2 was significantly higher than HCC at T1, T3 and T4 (effect of sample collection moment: F_3,41 = 12.78, p < 0.0001). The dog’s weight class, age class, sex, reason for admission, kennel history and melanin type also explained HCC variability. No significant difference in HCC was found between shelter dogs T1 and control pet dogs in their own homes (n = 20, one sample, t = − 1.24, p = 0.219). A significant but moderate positive correlation between HCC and urinary cortisol:creatinine ratios was found (т = 0.3, p < 0.001). As HCC increased in the shelter, the use of this non-invasive parameter appears a useful additional tool in dog welfare research.

The role of artificial photo backgrounds of shelter dogs on pet profile clicking and the perception of sociability

With the increasing prevalence of technology, the internet is often the first step for potential pet owners searching for an adoptable dog. However, best practices for the online portrayal of shelter and foster dogs remain unclear. Different online photo backgrounds appearing on adoption websites for shelter dogs may impact adoption speed by influencing viewer interest. Online clicking behaviour on pet profiles and human-directed sociability, broadly defined, has been previously linked to increased adoption likelihood. Therefore, the objective of this study was to determine the relationship between photo backgrounds of shelter dogs and online clicking as well as perceived human-directed sociability. In a virtual experiment, 680 participants were asked to rank the sociability and friendliness of four different adoptable dogs on a scale from 0–10. The photo background of each dog was digitally altered and randomly assigned to four experimental background conditions: 1) outdoor, 2) home indoor, 3) in-kennel, and 4) plain coloured. As a proxy for adoption interest, a link to the dog’s adoption profile was presented on each slide and the clicking behaviour of participants on this link was recorded. Mixed logistic regression and Poisson models revealed that background did not affect participants’ link-clicking behaviour (chisq = 3.55, df = 3, p = .314) nor perceptions of sociability (statistic = 6.19, df = 3, p = .103). Across all backgrounds, only 4.74% of presented slides culminated in participant link-clicking. Sociability scores also did not predict link clicking. Assessment of participant-related factors and dog ID revealed that link-clicking and sociability scores of photographs were influenced by differences between dogs themselves and unaffected by participants’ awareness of study hypotheses. We conclude that artificial background types did not affect participant responses. The results demonstrate the importance of empirical data in making marketing decisions in animal shelters. Understanding which aspects of online marketing materials impact viewer interest will provide guidance for both animal shelter personnel and foster families to improve the speed of adoption of the animals in their care.

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.

In search of the optimal enrichment program for zoo-housed animals

Zoo-housed animals are regularly exposed to new forms of environmental enrichment to make their lives less predictable. However, providing new enrichment can have unpredictable effects. We evaluated the effectiveness of two enrichment regimes: (1) providing only new enrichments - "Novelty" and (2) only familiar enrichments - "Familiar." In this case study, enrichment efficacy was assessed using activity budget analysis and novel object tests. The subjects were two focal animals: the golden jackal (Canis aureus) and the European badger (Meles meles). Our results suggest that both assessment methods provided similar conclusions about the animal's welfare. The "Familiar" treatment significantly increased activity and decreased abnormal behavior in the jackal's activity budget, who avoided novel objects in her baseline novel object test. The Novelty treatment resulted in the growth of time the jackal spent in the moat instead of the main enclosure, and an increase in avoidance and abnormal behaviors. In contrast, the badger demonstrated a high intensity of exploratory behavior in the baseline novel object test, and both regimes led to an increase in the activity budget of the badger. We propose that a stable, but complex enrichment can be an effective robust tool to increase animal welfare, but its efficacy depends on the novelty preference of individual animals. A novel object test can be a rapid tool to assess individual animals' novelty preferences, and this information may help to choose optimal enrichment regimes for individual animals.

Effects of a single oral dose of gabapentin on storm phobia in dogs: A double-blind, placebo-controlled crossover trial

BACKGROUND

Storm phobia in companion dogs is a common disorder that significantly impacts dogs' welfare. Gabapentin, the action of which is only partially understood, is widely used for its antiepileptic and analgesic properties. Only recently, the veterinary community began to use gabapentin to address phobia and anxiety in dogs. This study tested gabapentin to lower fear responses of dogs during a thunderstorm event.

METHODS

Eighteen dogs suffering from storm phobia completed our double-blind, placebo-controlled crossover trial. Each dog's behaviour was evaluated twice by his owner: once under placebo, once under gabapentin. The treatment was orally administered at least 90 min before the exposure. Gabapentin was given at a dose ranging from 25 to 30 mg/kg.

RESULTS

Our results indicate a significant reduction of the fear responses of dogs under gabapentin. The adverse effects were rare, and the most frequent amongst them was ataxia.

CONCLUSION

In this trial, gabapentin appears to be an efficient and safe molecule that should be considered as part of the treatment plan of storm phobia in dogs.

Educating dog owners: how owner–dog interactions can benefit from addressing the human caregiving system and dog-directed parenting styles

Dogs need to adapt to a human environment to enhance their welfare and to avoid risks of undesired dog behaviour and relinquishment. Crucial to this adaptation may be how an owner interacts with the dog. Owner–dog interactions may be influenced by the human caregiving system with regard to how care, protection and resources are provided. This narrative review discusses how a consideration of the human caregiving system can benefit owner–dog interactions. Literature suggests that the human caregiving system and parenting styles could influence owner–dog interactions. Owner–dog education may improve these interactions. However, studies on owner–dog education present mixed outcomes for the dog. Also, only a few studies address owner outcomes, indicating a gap that needs filling. It is concluded that, when intervening in owner–dog interactions, more attention should be directed to aspects of human psychology. Dog-directed parenting styles can form one strategy as to improve owner–dog interactions and dog welfare.

Investigating the Impact of Brief Outings on the Welfare of Dogs Living in US Shelters

Social isolation likely contributes to reduced welfare for shelter-living dogs. Several studies have established that time out of the kennel with a person can improve dogs' behavior and reduce physiological measures of stress. This study assessed the effects of two-and-a-half-hour outings on the urinary cortisol levels and activity of dogs as they awaited adoption at four animal shelters. Dogs' urine was collected before and after outings for cortisol:creatinine analysis, and accelerometer devices were used to measure dogs' physical activity. In total, 164 dogs participated in this study, with 793 cortisol values and 3750 activity measures used in the statistical analyses. We found that dogs' cortisol:creatinine ratios were significantly higher during the afternoon of the intervention but returned to pre-field trip levels the following day. Dogs' minutes of low activity were significantly reduced, and high activity significantly increased during the outing. Although dogs' cortisol and activity returned to baseline after the intervention, our findings suggest that short-term outings do not confer the same stress reduction benefits as previously shown with temporary fostering. Nevertheless, it is possible that these types of outing programs are beneficial to adoptions by increasing the visibility of dogs and should be further investigated to elucidate these effects.

Neurobiology of anesthetic-surgical stress and induced behavioral changes in dogs and cats: A review

The anesthetic-surgical stress response consists of metabolic, neuroendocrine, hemodynamic, immunological, and behavioral adaptations through chemical mediators such as the adrenocorticotropic hormone, growth hormone, antidiuretic hormone, cortisol, aldosterone, angiotensin II, thyroid-stimulating hormone, thyroxine, triiodothyronine, follicle-stimulating hormone, luteinizing hormone, catecholamines, insulin, interleukin (IL)-1, IL-6, tumor necrosis factor-alpha, and prostaglandin E-2. Behavioral changes include adopting the so-called prayer posture, altered facial expressions, hyporexia or anorexia, drowsiness, sleep disorders, restriction of movement, licking or biting the injured area, and vocalizations. Overall, these changes are essential mechanisms to counteract harmful stimuli. However, if uncontrolled surgical stress persists, recovery time may be prolonged, along with increased susceptibility to infections in the post-operative period. This review discusses the neurobiology and most relevant organic responses to pain and anesthetic-surgical stress in dogs and cats. It highlights the role of stress biomarkers and their influence on autonomous and demeanor aspects and emphasizes the importance of understanding and correlating all factors to provide a more accurate assessment of pain and animal welfare in dogs and cats throughout the surgical process.

Cannabis sativa L. may reduce aggressive behaviour towards humans in shelter dogs

Among the phytocomplex components of Cannabis sativa L., cannabidiol (CBD) has a recognised therapeutic effect on chronic pain. Little is known about the veterinary use of CBD in dogs. Even less is known on the effects of CBD on dog behaviour, especially in shelters. The purpose of this study was to determine if CBD affects stress related behaviour in shelter dogs. The sample consisted of 24 dogs divided into two groups that were created by assigning the dogs alternately: 12 dogs were assigned to the treatment group and 12 to the control group. Extra virgin olive oil, titrated to 5% in CBD was given to treated group; the placebo consisted of olive oil only, dispensed daily for 45 days. Behavioural data were collected using the 'focal animal' sampling method with 'all occurrences' and '1/0' methods for 3 h: before (T0), after 15 days (T1), after 45 days of treatment (T2) and after 15 days from the end of the treatment (T3). Treated dogs showed reduced aggressive behaviour toward humans following the treatment (Friedman Test: χ2 = 13.300; df = 3; N = 12; p = .004; adj. sig. p = 0.027), but the difference in the decrease of aggressive behaviour between the two groups was not significant (Mann-Whitney U test, T2-T0: Z = - 1.81; N = 24; p = 0.078). Other behaviours indicative of stress, such as displacing activities and stereotypes, did not decrease. Despite some non-significant results, our findings suggest that it is worth doing more research to further investigate the effect of CBD on dog behaviour; this would be certainly valuable because the potential for improving the welfare of dogs in shelters is priceless.

Do Canine Behavioural Assessments and Characteristics Predict the Human-Dog Interaction When Walking on a Leash in a Shelter Setting?

Simple Summary

We explored 370 human-dog interactions in an animal shelter when volunteers walked shelter dogs on a leash, considering the effects of canine demographics and the results of the shelter’s canine behavioural assessments. Results showed that dogs that were more relaxed during the shelter assessment (i.e., when socialising with humans or being left alone in a new environment) were less reactive on the leash, with lower tension and pulling frequency. Moreover, socialised and relaxed dogs displayed more positive body language, such as tail in a high position, gazing at the handler, and exploring the environment. When walking with these dogs, volunteers utilised fewer verbal guidance cues and body language during the walk. In addition to the canine behaviour assessment, there were correlations between canine demographics (i.e., age, skull shape, body size, and previous ownership history) and the behavioural interaction and humans’ perception. Finally, volunteers perceived the walk as less satisfactory when they needed to pull the leash harder during the walk. This research suggests that the RSPCA behavioural assessment may be useful in predicting the behaviour of shelter dogs when walked by volunteers.

Abstract

Inappropriate leash reactivity is one of the most common problems in shelter dogs, which negatively affects the health of dogs and reduces their adoptability. We explored 370 human-dog interactions, involving 74 volunteers and 111 dogs, in an animal shelter when volunteers walked shelter dogs on a leash, considering the effects of canine demographics and the results of the shelter’s canine behavioural assessments. The interaction was video recorded and coded using ethograms, and a leash tension meter was used to measure the pull strength of dogs and handlers. Results showed that dogs that were more relaxed during the shelter assessment (i.e., when socialising with humans or being left alone in a new environment) were less reactive on the leash, with lower tension and pulling frequency. Moreover, socialised and relaxed dogs displayed more positive body language, such as tail in a high position, gazing at the handler, and exploring the environment. When walking with these dogs, volunteers utilised fewer verbal cues and body language during the walk. In addition to the canine behaviour assessment, there were correlations between canine demographics and the behavioural interaction and humans’ perception. Finally, volunteers perceived the walk as less satisfactory when they needed to pull the leash harder during the walk. This research suggests that the RSPCA behavioural assessment may be useful in predicting the behaviour of shelter dogs when walked by volunteers.

Exploring Anhedonia in Kennelled Dogs: Could Coping Styles Affect Hedonic Preferences for Sweet and Umami Flavours?

Simple Summary

Kennelled dogs are susceptible to suffer chronic stress when social interactions with conspecifics and spatial needs are long-term restricted. Chronic stress may affect pleasure perception of food and solutions in dogs as observed in several animals, a phenomenon known as anhedonia. However, little information exists on how different coping styles could prevent the onset of anhedonia. Fourteen kennelled Beagle dogs were used to study the acceptability and preference for different dilute palatable sucrose and monosodium glutamate (MSG) solutions. Coping style of animals was previously evaluated through a modified human-approach test. This test consisted in assessing whether or not dogs approached an unfamiliar human when a feeding opportunity was presented, classifying them as close dogs (CD; proactive) or distant dogs (DD; reactive) respectively. It was observed that DD presented a lower intake of both sucrose and MSG dilute solutions compared with CD. Moreover, DD exhibited a higher consumption of MSG than CD at the highest concentrations, supporting that their intake depends on solution palatability. Finally, DD did not prefer sucrose or MSG solutions over water at any dilute solution offered. Together, these results suggest that dogs that are categorized as reactive animals could diminish their ability to perceive dilute palatable solutions reflecting depressive-like behaviours such as anhedonia.

Abstract

Kennelled dogs are at risk of suffering chronic stress due to long-term spatial, social and feeding restrictions. Chronic stress may decrease the dogs’ capacity to feel pleasure when facing hedonic experiences, modifying their perception for palatable ingredients. However, different abilities to cope with environmental stressors could prevent the onset of anhedonia. Fourteen kennelled Beagle dogs were used to study the acceptability and preference for different dilute sucrose and monosodium glutamate (MSG) solutions. Coping style of animals was previously evaluated through a human approach test (HAT) and classified as close dogs (CD; proactive) or distant dogs (DD; reactive) according to whether or not they approached an unfamiliar human when a feeding opportunity was presented. Consumption results were analysed taking into account the sucrose/MSG concentrations, HAT (CD or DD), age, and weight of the animals. DD presented a lower intake of sucrose (p = 0.041) and MSG (p = 0.069) solutions compared with CD. However, DD exhibited a higher consumption of MSG than CD at its highest concentrations, supporting that their intake depends on solution palatability. Finally, DD did not prefer sucrose or MSG solutions over water at any dilute solution offered. Together, these results suggest that dogs that are categorized as reactive animals could diminish their ability to perceive dilute palatable solutions, reflecting depressive-like behaviours as anhedonia.

Reliability of observer ratings: Qualitative behaviour assessments of shelter dogs using a fixed list of descriptors

Qualitative Behaviour Assessment (QBA) is a whole-animal approach used to quantify the expressive style of animals’ behaviour. The aim of this study was to evaluate the inter-observer reliability of QBA of shelter dogs using a fixed list of descriptors. The fixed list of 20 terms was generated using a group of experts and literature reviews. In the pilot study, seven veterinary students scored 12 two-minute video clips, and in the main study, 22 final year veterinary nurse students and third-year veterinary students scored the same videos. The two datasets were analysed using Principal Component Analysis (PCA), and the level of agreement for the main components and individual terms was assessed using Kendall's coefficient of concordance (W). In the pilot study, the observer agreement was 0.89 for PC1 and 0.78 for PC2, indicating high inter-observer agreement. The reliability was similarly high for both components in the main study (0.88 and 0.79, respectively). Results also demonstrated high or moderate agreement for most of the terms included in the fixed list. We propose that this approach can be a useful learning tool for students. Our results support further exploration of this method for the assessment of shelter dog welfare by direct observation.

Salivary cortisol as a marker of acute stress in dogs: a review

Public interest in the welfare of domestic dogs has increased in recent years. Dogs under human care should experience as little stress as possible, and as such it is necessary to measure and quantify their levels of stress. Stress parameters that can be measured noninvasively may help to identify the poor welfare of animals. This review aimed to determine whether and under what conditions the hormone cortisol in dog saliva can be used as a noninvasive acute stress marker. The use of salivary cortisol as a stress marker has some disadvantages, which can lead to data misinterpretations. A key factor is the standardized method of sampling and subsequent processing before analysis. In addition, possible circadian alternation and individual variability of cortisol hormone levels should be consistently considered during the preparation of the experimental scheme, statistical data processing and final interpretation of the results. Because of the complex nature of the stress response, the observation of salivary cortisol should be supplemented with behavioral observations, but it should be noted that behavioral stress symptoms may not always be positively correlated with stress hormone production. Besides behavioral observations, it is advisable to supplement the measurement of cortisol by other salivary stress markers of sympathetic-adrenal-medullary and hypothalamic-pituitary-adrenal pathways. This comprehensive assessment of the stress impact on the individual will enable one to characterize the level and type of stress.

Physiological stress reactivity and recovery related to behavioral traits in dogs (Canis familiaris)

This study investigated whether stress responsiveness (in one context) can be used to predict dog behavior in daily life. On two occasions (N_T1 = 32 puppies; N_T2 = 16 young adults), dogs’ physiological stress response after a behavioral test at home was measured in terms of reactivity (10 min post-test) and recovery (40 min post-test) for three salivary markers: cortisol, chromogranin A (CgA) and secretory immunoglobulin A (sIgA). For each marker, it was determined whether dogs with a strong physiological response displayed different behavior in daily life compared to dogs with a weaker physiological response. The results revealed three main findings: first, for CgA and cortisol, different patterns were identified according to sample time. High reactivity related to desirable traits, whereas slow recovery after the behavioral test related to undesirable traits. The findings suggest that increased levels of CgA and cortisol 10 minutes after the behavioral test reflected an adaptive stress response, whereas elevated levels 40 minutes after the test reflected unsuccessful coping. Second, patterns for sIgA differed from CgA and cortisol: significant associations were only found with behavioral traits at T2, mostly considered desirable and related to Trainability. Possibly, the delayed reaction pattern of sIgA caused this difference between markers, as sIgA reflects the (secondary) immune response to stress, due to immunosuppressive effects of cortisol. Third, predictive capacity of puppies’ physiological stress response (T1) was inconclusive, and contrary relations were found with behavioral traits at T2, suggesting that developmental factors play an important role. This study provides new insights about the relation between stress physiology and behavioral traits, and methodological advice is given to study these patterns further. In conclusion, physiological markers could provide additional insights in dogs’ tendencies to display certain behaviors, especially at the young adult stage. Further studies are needed to confirm these patterns.

Welfare Assessment in Shelter Dogs by Using Physiological and Immunological Parameters

Simple Summary

In “no-kill policy” countries, many dogs live in shelters. Several social, environmental, and management challenges can put the welfare of shelter dogs at risk. More knowledge is still needed on how to assess shelter dog welfare. This study aimed to evaluate the state of welfare of a group of dogs entering a shelter using physiological and immunological parameters by exploring the value of some biological indicators obtained by non-invasive methods. Considering that early welfare assessment could improve the management of subjects more prone to developing distress, measurements were taken at the time of admission and four weeks after the dogs entered the shelter. A multivariate statistical approach was used to comprehensively evaluate the relationship between the variables investigated. A reduction in the values of the measured physiological and immune parameters over time suggested an improvement in the dogs’ welfare after four weeks of being in the shelter compared to the initial capture and admission time. Findings also highlighted that some of the parameters investigated, such as neutrophils, lymphocytes, and fecal cortisol and lysozyme could be used for the welfare assessment of dogs entering a shelter.

Abstract

This study aimed to evaluate the state of welfare of a group of dogs during the first month after entering the shelter by using different stress parameters. Blood and fecal samples were collected from a group of 71 dogs at the time of admission to the shelter. In 46 of these dogs, sampling was repeated after four weeks. Well-recognized welfare biomarkers, such as fecal cortisol and leukocytes, as well as some innovative parameters (β-endorphin and lysozyme) were determined. Uni- and multivariate statistical analyses were used to evaluate their interactions and changes over time. Neutrophils (p < 0.01), lysozyme (p < 0.05), and fecal cortisol (p < 0.05) decreased, while lymphocytes (p < 0.05) increased after four weeks compared to the first days of being in the shelter, suggesting an improvement in the dogs’ welfare over time. A principal component analysis extracted three bipolar components (PCs), explaining 75% of the variance and indicating negative associations between neutrophil and lymphocyte (PC1), lysozyme and β-endorphin (PC2), cortisol and lysozyme (PC3). The associations between these variables within each PC also confirmed the intricate relationships between the hypothalamic-pituitary-adrenal (HPA) axis and the immune system as well as the importance of a multiparametric approach in evaluating welfare.

Assessing the welfare of kennelled dogs-A review of animal-based measures

Hundreds of thousands of dogs are housed in kennels worldwide, yet there are no standard protocols for assessing the welfare of dogs in these environments. Animal science is focusing increasingly on the importance of animal-based measures for determining welfare states, and those measures that have been used with kennelled dogs are reviewed in this paper with particular focus on their validity and practicality. From a physiological standpoint, studies using cortisol, heart rate and heart rate variability, temperature changes, and immune function are discussed. Behavioural measures are also of great relevance when addressing canine welfare, thus studies on fear and anxiety behaviours, abnormal behaviours like stereotypies, as well as responses to strangers and novel objects are reviewed. Finally, a limited number of studies attempting to use cognitive bias and learning ability are also mentioned as cognitive measures. The literature to date provides a strong background for which measures may be useful in determining the welfare of kennelled canines, however more research is needed to further assess the value of using these methods, particularly in regard to the large degree of individual differences that exist between dogs.

Enhancing Success of Veterinary Visits for Clients With Disabilities and an Assistance Dog or Companion Animal: A Review

Despite increasing information on enhancing client communication and compliance/adherence in veterinary medicine, literature focusing on special cases remains limited: working with clients with special needs, challenges or disabilities, or when the patient is an assistance or emotional support animal. This paper summarizes current recommendations on how best to build successful working relationships with these clients, including action items to implement in practice. In addition, this paper reviews current literature on important considerations for care of assistance dogs as patients.

Laterality as a Predictor of Coping Strategies in Dogs Entering a Rescue Shelter

It has been reported that during the first few days following entry to a kennel environment, shelter dogs may suffer poor welfare. Previous work suggests that motor bias (the preferred use of one limb over the other) can potentially be used as an indicator of emotional reactivity and welfare risk. In this study, we investigate whether paw preference could be used as a predictive indicator of stress coping (measured using cortisol levels and behavioural observation) in a sample of 41 dogs entering a rescue shelter. Cortisol levels and behavioural observations were collected for one week after admission. We scored the dogs’ paw preference during a food-retrieval task. Our results showed that increasing left-pawedness was associated with a higher expression of stress-related behaviours such as frequent change of state, vocalisations and lower body posture. These results are in keeping with previous findings showing that left-limb biased animals are more vulnerable to stress. Paw preference testing may be a useful tool for detecting different coping strategies in dogs entering a kennel environment and identifying target individuals at risk of reduced welfare.

Measuring physiological stress in the common marmoset (Callithrix jacchus): Validation of a salivary cortisol collection and assay technique

Cortisol levels are often used as a physiological measure of the stress response in captive primates, with non-invasive measures of this being an important step in welfare assessment. We report a method of collecting saliva samples voluntarily from unrestrained captive common marmosets (Callithrix jacchus), and validate an enzyme-linked immunosorbent assay (ELISA) technique previously unused in this species. Saliva samples were collected from marmosets housed in pairs in a UK laboratory. The assay showed parallelism, precision, accuracy and sensitivity, meeting the criteria typically used to investigate the effectiveness of new analytical techniques. Use of Salimetrics® Oral Swabs considerably increased the amount of cortisol recovered in comparison with previous studies using cotton buds. However, while use of banana on the swabs can encourage chewing, it may influence results. Although increases in cortisol levels have traditionally been interpreted as an indicator of stress in primates, there are many factors that affect the hypothalamic-pituitary-adrenal axis, with some studies showing decreases in cortisol levels post-stressor. Following a likely stressful event (capture for weighing), we also found cortisol levels significantly decreased, possibly due to social buffering or 'blunting' of the HPA axis. Order of weighing also had an effect. The method therefore provided an effective non-invasive means of assessing acute changes in cortisol level that may be more useful than previous methods, improving our ability to study physiological aspects of welfare in primates. We discuss methodological considerations, as well as implications of using cortisol as a measure of stress.

Modelling personality, plasticity and predictability in shelter dogs

Behavioural assessments of shelter dogs (Canis lupus familiaris) typically comprise standardized test batteries conducted at one time point, but test batteries have shown inconsistent predictive validity. Longitudinal behavioural assessments offer an alternative. We modelled longitudinal observational data on shelter dog behaviour using the framework of behavioural reaction norms, partitioning variance into personality (i.e. inter-individual differences in behaviour), plasticity (i.e. inter-individual differences in average behaviour) and predictability (i.e. individual differences in residual intra-individual variation). We analysed data on interactions of 3263 dogs (n = 19 281) with unfamiliar people during their first month after arrival at the shelter. Accounting for personality, plasticity (linear and quadratic trends) and predictability improved the predictive accuracy of the analyses compared to models quantifying personality and/or plasticity only. While dogs were, on average, highly sociable with unfamiliar people and sociability increased over days since arrival, group averages were unrepresentative of all dogs and predictions made at the individual level entailed considerable uncertainty. Effects of demographic variables (e.g. age) on personality, plasticity and predictability were observed. Behavioural repeatability was higher one week after arrival compared to arrival day. Our results highlight the value of longitudinal assessments on shelter dogs and identify measures that could improve the predictive validity of behavioural assessments in shelters.

Evaluating pair versus solitary housing in kennelled domestic dogs (Canis familiaris) using behaviour and hair cortisol: a pilot study

Numerous studies conducted to assess welfare of domestic dogs housed in kennel facilities have reported that these dogs experience suboptimal living conditions. One important goal of improving welfare of kennelled dogs is to reduce their stress levels, and one recommended approach for improving welfare of kennelled dogs is group or social housing. The beneficial effects of management changes designed to achieve this goal should be measurable in individual animals. Stress is evident through behaviours exhibited, as well as via the concentration of cortisol, a key hormone reflecting stress. Using behavioural and hair cortisol measures, we conducted a pilot study to measure the impact of switching dogs housed in a long-term kennels facility from solitary to pair housing, using both within-subjects and between-groups comparisons. Considerable individual variation in dog responses was noted, with only two of eight pair-housed dogs showing significant declines in multiple stress-related behaviours once in pair housing. The most sensitive behaviours were active vigilance and repetitive movements (such as jumping and pacing). Barking was reduced overall in the facility following the housing change, even among dogs still in solitary housing. The long-term stress as reflected in hormone deposition in hair also provided encouraging indications that the dogs experienced lower stress levels when in paired housing; dogs showed a significant decline in hair cortisol levels from the first (prehousing change) to second (postintervention) samples. Domestic dogs are social animals, and numerous indications of potential benefit were recorded with no negative impacts seen. Based on our findings, we recommend pair or group housing of compatible dogs as a promising addition to the strategies available to those seeking to improve welfare of kennelled dogs. Future studies using higher numbers of animals and that include tracking of hair cortisol, vigilance behaviour, repetitive movements and barking would be desirable.

Effects of Sheltering on Behavior and Fecal Corticosterone Level of Elderly Dogs

In Japan, the human population is aging rapidly, and the abandonment of dogs by the elderly people who have died or been hospitalized becomes a problem. It is hypothesized that elderly dogs have difficulty adapting to the novel circumstances when brought to an animal shelter. Therefore, the objective of this study was to assess stress levels and demonstrate stress responses of elderly dogs just after admission to an animal shelter. As stress indicators, fecal corticosterone levels and changes in the ethogram of the dogs were investigated during the first week of admittance. Fecal corticosterone levels (mean ± SE) stayed high during the first week of residence, although they fell gently from the day after admittance (16650.1 ± 3769.7 ng/g) to the seventh day (12178.4 ± 2524.4 ng/g) (P < 0.001). The proportions of behavioral expressions changed as the days passed (P < 0.001). In particular, stereotypies decreased from 35.7% on the first day to 2.6% on the sixth day, and time spent sleeping increased from 0.0 to 42.7%. These results indicate that elderly dogs admitted to an animal shelter seem to behaviorally adapt themselves to their novel circumstances but might be stressed even on the seventh day of residence.

A systematic review and meta-analysis of salivary cortisol measurement in domestic canines

Salivary cortisol is widely used as an indicator of stress and welfare in canine research. However, much remains unclear about the basic features of this hormone marker in domestic dogs. This systematic review and meta-analysis aimed to determine a reference range for cortisol concentration in the saliva of dogs and examine how canine characteristics, environmental effects and experimental considerations relate to salivary cortisol concentrations. A systematic review of literature databases and conference proceedings from 1992 to 2012 identified 61 peer-reviewed studies using domestic dog salivary cortisol. Researchers were contacted via email, and 31 raw data sets representing a total of 5,153 samples from 1,205 dogs were shared. Meta-analysis provided a cortisol concentration range of 0 to 33.79 μg/dL (mean 0.45 μg/dL, SEM 0.13). Significant effects (P < 0.05) were found for sex and neuter status, age, regular living environment, time in environment before testing, testing environment, owner presence during testing, and collection media. Significant effects were not found for dog breed, body weight, dog type, coat color, assay type, exercise, eating, or use of salivary stimulant. Care should be taken when using cortisol studies for dogs at a group or population level as there is a large amount of intraindividual and interindividual variability and external variables could influence salivary cortisol concentration. This analysis highlights the importance of carefully controlling experimental design to compare samples within and between individual dogs, as well as establishing and using best practices for saliva collection. Caution should be exercised in comparing different studies, as the results could be the reflection of a plethora of factors.

Effects of sheltering on physiology, immune function, behavior, and the welfare of dogs

Approximately 4 million dogs live in animal shelters each year. However, understanding and measuring the welfare of these kenneled dogs presents a challenge. One way to determine welfare is by assessing how stay at the shelter influences physiology, immune function, and behavior of the dogs. Prior research, from all of these domains, has not resulted in clear conclusions on how the animal shelter influences the well-being of dogs. One robust finding is that, when placed into a kennel environment, dogs experience a spike in cortisol levels followed by a decrease to original at-home levels. Current evidence cannot differentiate between several proposed hypotheses that may be responsible for this pattern. In addition, very few studies have assessed the effects of kenneling on immune function of dogs, and of these, no consistent findings have emerged. However, this line of inquiry can have a large impact as infectious diseases are rampant in animal shelters. The ability of behavioral measures to inform us about the welfare of dogs is discussed by reviewing published and new data on the effects of kenneling on dog behavior. Prior research has suffered from a lack of consistent operational definitions when defining abnormal behavior in dogs, resulting in difficult to interpret results. Research on the well-being of individual dogs, rather than on group averages, may be a fruitful next step in determining and improving the welfare of dogs housed in shelters.

Quantification of salivary cortisol from captive dingoes (Canis dingo) in relation to age, sex, and breeding season: implications for captive management

Captive-breeding programs can play a key role in the conservation of threatened species such as the Australian dingo (Canis dingo). It is important to determine whether holding and rearing practices impose stressors that impact negatively on program outcomes and the health and wellbeing of the captive population. Despite evidence that chronic stress has significant welfare implications, our understanding of ‘stress’ in either wild or captive dingoes remains limited. In a first attempt to rectify this, we report salivary cortisol concentrations in juvenile and adult dingoes held in a captive colony. Dingo puppies (n = 8, M = 0.484 ± 0.09 μg dL–1) were found to have higher concentrations than adults (n = 12, M = 0.106 ± 0.031 μg dL–1) (P < 0.0001). Concentrations in adult females (n = 6, M = 0.113 ± 0.030 μg dL–1) and males (n = 6, M = 0.099 ± 0.033 μg dL–1) did not significantly differ (P = 0.4740). Our preliminary findings also suggest that during the annual breeding season, males (but not females) have elevated levels of corticosteroids. Establishing a reference range for cortisol concentrations is vital for researchers and wildlife carers attempting to measure stressors in both captive and wild dingo populations. This study provides useful insight into the influence of time of day, development, and seasonality on cortisol concentrations. Suggestions for future research and implications of routine cortisol evaluation to aid better management practices are also discussed.