Epidemiology of heat-related illness in dogs under UK emergency veterinary care in 2022.

BACKGROUND: Dogs are exposed to increasing environmental risk for developing heat-related illness (HRI), with 2022 recorded as the hottest year to date in the UK and most of Europe. METHODS: This study used VetCompass data to report the incidence risk, event fatality rate and canine risk factors for HRI in dogs presenting to Vets Now emergency care practices in the UK during 2022. RESULTS: From the clinical records of 167,751 dogs under care at Vets Now emergency clinics in 2022, 384 HRI events were identified. The 2022 incidence risk of HRI within the Vets Now caseload was 0.23% (95% confidence interval [CI]: 0.21%‒0.25%), with an event fatality rate of 26.56% (95% CI: 21.66%-32.25%). Multivariable analysis identified breed, age and sex/neuter status as risk factors for HRI. Brachycephalic dogs had 4.21 times the odds of HRI compared to mesocephalic dogs (95% CI: 3.22‒5.49, p < 0.001). LIMITATIONS: The clinical data used in this study were not primarily recorded for research and had some substantial levels of missing data (especially patient bodyweight). CONCLUSION: In order to protect canine welfare, improved long-term mitigation strategies are urgently needed to minimise HRI risk and associated fatality in UK dogs.

Mobility, functionality and functional mobility: A review and application for canine veterinary patients.

Mobility is an essential aspect of a dog's daily life. It is defined as the ability to move freely and easily and deviations from an animals' normal mobility capabilities are often an indicator of disease, injury or pain. When a dog's mobility is compromised, often functionality (ability to perform activities of daily living [ADL]), is also impeded, which can diminish an animal's quality of life. Given this, it is necessary to understand the extent to which conditions impact a dog's physiological ability to move around their environment to carry out ADL, a concept termed functional mobility. In contrast to human medicine, validated measures of canine functional mobility are currently limited. The aim of this review is to summarise the extent to which canine mobility and functionality are associated with various diseases and how mobility and functional mobility are currently assessed within veterinary medicine. Future work should focus on developing a standardised method of assessing functional mobility in dogs, which can contextualise how a wide range of conditions impact a dog's daily life. However, for a true functional mobility assessment to be developed, a greater understanding of what activities dogs do on a daily basis and movements underpinning these activities must first be established.

Post-exercise management of exertional hyperthermia in dogs participating in dog sport (canicross) events in the UK.

Exercise is a common trigger of heat-related illness (HRI) events in dogs, accounting for 74% of canine HRI cases treated under primary veterinary care in the United Kingdom. However, few empirical studies have evaluated the effectiveness of differing cooling methods for dogs with exertional hyperthermia or HRI. This study aimed to prospectively evaluate effects of ambient conditions and post-exercise management practices (cooling methods and vehicular confinement) on the post-exercise temperature change of dogs participating in UK canicross events. Canine temperature was recorded at three intervals post-exercise: as close as possible to 0- (immediately post-exercise), 5-, and 15-min post-exercise. Ambient conditions and post-exercise management were recorded for 115 cooling profiles from 52 dogs. In 28/115 (24.4%) profiles, the dog's temperature increased during the first 5-min post-exercise. Overall, 68/115 (59.1%) profiles included passive cooling (stood or walked outside), 35 (30.4%) active cooling (cold-water immersion or application of a cooling coat), and 12 (10.4%) involved no cooling and were immediately housed in vehicles. No dogs developed hypothermia during the study and no adverse effects were observed from any cooling method. In hyperthermic dogs, overall post-exercise body temperature change was significantly negatively associated (i.e. the dogs cooled more) with 0-min post-exercise body temperature (ß = -0.93, p < 0.001), and not being housed in a vehicle (ß = -0.43, p = 0.013). This study provides evidence cold-water immersion (in water at 0.1-15.0 °C) can be used to effectively and safely cool dogs with exertional hyperthermia. Progressive temperature increases in many dogs - even after exercise has terminated - supports the message to "cool first, transport second" when managing dogs with HRI. When transporting dogs post-exercise or with HRI even after active cooling, care should be taken to cool the vehicle before entry and promote air movement around the dog during transport to facilitate ongoing cooling and prevent worsening of hyperthermia during travel.

Effect of harness design on the biomechanics of domestic dogs (Canis lupus familiaris).

Harnesses have become increasingly popular and whilst there are benefits to harnesses, the impact of harness design on canine biomechanics, and thus physical health and welfare is largely unknown. The purpose of this study was to assess the effect of three popular commercially available harnesses on canine locomotion in 66 domestic dogs. Dogs were filmed moving on a loose lead over a Tekscan Strideway gait analysis system. Stride length as a proportion of limb length (calculated as distance from the elbow to the floor), body weight distribution in the front versus the hind limbs (%), and minimum and maximum apparent angles of the lateral epicondyle of humerus (LEH) and greater tubercle of humerus (GTH) during the motion cycle were measured. Except for GTH angles, there were significant differences in all the investigated metrics. Differences varied across breeds/breed types. It is recommended that, when purchasing and fitting harnesses for dogs, owners and harness fitters treat dogs on an individual basis. The impact of pulling in harness on dog gait requires investigation as dogs may experience greater restrictions when pulling than during locomotion on a loose lead.

Cooling Methods Used to Manage Heat-Related Illness in Dogs Presented to Primary Care Veterinary Practices during 2016-2018 in the UK.

The management of heat-related illness (HRI) in dogs has received limited attention in the veterinary literature, especially regarding effective cooling methods. Guidelines published in 2016 for prehospital management of dogs with HRI advised "cool first, transport second", and recommended using cold-water immersion and evaporative cooling (water application with air movement) as the optimal approaches to reduce the patient's temperature. The current retrospective cross-sectional observation study analysed electronic patient records from the VetCompass programme to describe the cooling methods used in dogs with HRI presented to primary care veterinary practices during 2016-2018. Of 623 HRI events identified, 341 (54.74%, 95% CI 50.81-58.60%) included information on cooling in their clinical record. Of these, 74/341 (21.70%, 95% CI 17.65-26.38%) were cooled prior to transport for veterinary care. Overall, 23.97% (95% CI 19.24-29.44%) were cooled using one of the two recommended cooling methods, whilst the most common cooling method recorded was the application of wet towels (51.31%, 95% CI 45.34-57.24%). Canine cooling guidance and messaging in both the public and veterinary sectors requires urgent review to ensure that the most effective cooling methods are promoted because delays to canine temperature reduction worsen patient outcomes.

The Impact of COVID-19 Zoo Closures on Behavioural and Physiological Parameters of Welfare in Primates.

Primates are some of the most cognitively advanced species held in zoos, and their interactions with visitors are complex. The COVID-19 pandemic provided a unique opportunity to understand the impact of zoo visitors on animals, in comparison to "empty zoos". This study sought to understand the impact of facility closures and subsequent reopenings on behavioural and physiological parameters of welfare in four primate species housed in the UK: bonobos (Pan paniscus) (n = 8), chimpanzees (Pan troglodytes) (n = 11), and western lowland gorillas (Gorilla gorilla gorilla) (n = 6) held at Twycross Zoo (TZ); and olive baboons (Papio anubis) (n = 192) held at Knowsley Safari (KS). Behavioural data were collected from April-September 2020 (KS) and November 2020-January 2021 (TZ). Faecal samples were collected during morning checks from October-November (TZ) and July-November 2020 (KS). Faecal glucocorticoid metabolites (FGMs) were measured using ELISA kits. Statistical analysis for behavioural observations was undertaken using general linear models. Enclosure usage was assessed using t-tests and Mann-Whitney U-tests as appropriate. Bonobos and gorillas spent less time alone when facilities were open to the public (p = 0.004, p = 0.02 respectively). Gorillas spent less time resting when the facility was open to the public (p = 0.04), and chimpanzees engaged in more feeding (p = 0.02) and engagement with enrichment (p = 0.03) when the zoo was open to the public than when it was closed. Olive baboons performed less sexual and dominance behaviour and approached visitor cars more frequently when the safari park was opened to the public than they did the ranger's vehicle during closure periods. There were no significant changes in physiological parameters for any of the study species. The results suggest variable impacts of the zoo closures on zoo-housed primates. We recommend future work that seeks to understand the impact of individual-level differences on "visitor effects" and that differences between animal experiences in zoos and safari parks are further explored in a range of species.

Risk Factors for Severe and Fatal Heat-Related Illness in UK Dogs-A VetCompass Study.

Heat-related illness (HRI) is predicted to increase in dogs due to rising global temperatures. This study evaluated retrospective VetCompass veterinary clinical records to explore geographical variability and ambient conditions associated with HRI events in UK dogs, and report the intrinsic (canine) and extrinsic (location, trigger, ambient weather) risk factors for severe disease and fatal outcome in dogs affected by HRI. Dogs living in London had the greatest odds for developing HRI compared with dogs living in the North West (OR 1.9, 95% CI 1.31-2.74). The median ambient temperature on days of HRI events was 16.9 °C. For dogs with HRI, age, bodyweight and trigger were risk factors associated with severe disease. Age, skull shape and clinical grade of HRI presentation were associated with a fatal outcome. Whilst the majority of HRI events overall were triggered by exertion, the risk of severe disease was greater in situations where dogs could not escape the heat source (vehicular confinement), and the risk of death in HRI cases was greater for those dogs with reduced capacity to thermoregulate (older and brachycephalic dogs). These results highlight the need for better owner awareness of the factors that increase the risk of severe and fatal HRI, as a first stage in protecting canine welfare in the face of rising global temperatures.

Surveillance of heat-related illness in small animals presenting to veterinary practices in the UK between 2013 and 2018.

Background: Heat-related illness (HRI) can affect all companion animals and is likely to become more common as global temperatures rise. The misconception that HRI is primarily a result of dogs being trapped in hot cars, highlights a lack of awareness of HRI risk factors within the UK companion animal population. Aim: This project aimed to review all species of small animal presentations of HRI to UK veterinary practices participating in the Small Animal Veterinary Surveillance Network (SAVSNET), describe the inciting triggers and seasonality of HRI events, and review the clinical grade of canine patients presenting with HRI. Methods: Electronic consultation records were submitted by volunteer veterinary practices across the UK to SAVSNET. Cases were defined as animals presented for consultation with strong evidence of current, or recent heat induced illness during the study period (2013-2018). Results: The HRI cases included 146 dogs, 16 cats, 8 guinea pigs, 3 rabbits and 1 ferret. Of the 118 HRI cases with a recorded trigger, exercise was the primary trigger for dogs presenting (73.5%); 7 (6.9%) canine HRI events followed vehicular confinement. Environmental HRI was recorded as a trigger for the remaining dogs (19.6%), and for all cats, guinea pigs, rabbits and the ferret. Brachycephalic breeds comprised 21.2% of canine HRI cases, and all rabbits were brachycephalic breeds. Dogs with HRI were presented between April and October, with 42.5% during July, typically the UK's hottest month of the year. Cats with HRI were presented between May and September, with 75.0% during June and July. The smaller companion species-ferrets, rabbits and guinea pigs-were presented during the UK's summer months June to August. Conclusion: This study highlights the risk of HRI to all pet animals during the UK's warmer summer months (June to August). The findings support previous claims that exercise is the most common trigger of HRI in dogs, while environmental HRI (a hot ambient temperature) accounted for all HRI events in cats, rabbits, guinea pigs, and ferrets. Both brachycephalic dogs and rabbits were overrepresented, adding further evidence that owners of these animals should be particularly vigilant for HRI during hot weather.

Correction: Williams et al. Kinetics and Kinematics of Working Trials Dogs: The Impact of Long Jump Length on Peak Vertical Landing Force and Joint Angulation. Animals 2021, 11, 2804.

The authors wish to make the following correction to this paper [...].

Exploring Owner Perceptions of the Impacts of Seasonal Weather Variations on Canine Activity and Potential Consequences for Human-Canine Relationships.

Climate change is leading to more instances of seasonal weather variation. Studies have explored the impact of adverse winter weather on dog walking, but the impact on the dog's overall activity levels have not been previously considered. This study explored dog owner perceptions of the effects of both summer and winter weather on their dog's activity levels. An international online survey recruited 3153 respondents between May and December 2018, to explore the impact of summer and winter weather conditions on baseline activity levels. Owners reported their dogs were more impacted by cold (48.2% less likely to exercise their dog in the cold) and ice (64.0% less likely), than rain (25.3% were less likely). In hot weather, over 80% of owners reported reduced exercise duration and vigour for their dogs. Carrying water or walking near water to facilitate activity in the summer was the most popular mitigation strategy (90.8%). Participation in dog sports appeared to reduce the impact of winter weather on canine activity and increase owner awareness of cooling strategies to facilitate summer activity. Strategies to promote safe activity participation are needed to maintain canine activity levels amidst rising global temperatures, including better understanding of cooling strategies for exercising dogs.

Kinetics and Kinematics of Working Trials Dogs: The Impact of Long Jump Length on Peak Vertical Landing Force and Joint Angulation.

Working trials is a competitive canine discipline based on work undertaken by military and police dogs. A 9 ft long jump is a key component of the discipline. Research into landing forces and joint angulation in other canine disciplines has highlighted the potential for the occurrence of soft tissue injuries, predominantly in the front limbs. There is a paucity of work into the impact of spread/long jumps on joint angulation and peak vertical force (PVF) on landing, and limited research on working trials dogs generally. This study aimed to determine whether altering the length of the long jump impacted PVF and apparent joint angulation upon landing. 21 dogs regularly competing in working trials cleared the long jump at three lengths: 9 ft (full length), 8 ft, and 7 ft. The impact of altered long jump length on the PVF, apparent shoulder and carpus angulation, and duration of landing, were analysed using general linear mixed models. There was no significant relationship between the length of the long jump and PVF or joint angulation on landing (p > 0.05). Greatest joint compression was observed on landing after clearing 9 ft. Individual variability in landing joint angulation, PVF and force distribution of the left and right front limbs on landing was observed across all three experimental lengths. We recommend further research is undertaken to examine individual variability and the effect of training and experience in working trials participants, to provide evidence-based recommendations for training people and competing dogs in this discipline.

Proposing the VetCompass clinical grading tool for heat-related illness in dogs.

Heat-related illness is a potentially fatal condition in dogs. Rapid and accurate recognition of the severity can improve clinical management in affected dogs and lead to better outcomes. This study explored retrospective VetCompass veterinary clinical records to investigate the clinical signs recorded for dogs presenting with heat-related illness to primary-care veterinary practice from 2016 to 2018. The relative risk of death associated with these clinical signs was reported and used to develop a novel clinical grading tool. From the clinical records of 856 heat-related illness events, the most frequently recorded clinical signs were respiratory changes (68.73%) and lethargy (47.79%). The clinical signs with the highest relative risk of death were neurological dysfunction, gastrointestinal haemorrhage and bleeding disorders. The novel VetCompass Clinical Grading Tool for Heat-Related Illness in dogs defines three grades: mild (altered respiration, lethargy), moderate (gastrointestinal signs, a single seizure, episodic collapse) and severe (neurological dysfunction, gastrointestinal haemorrhage, bleeding disorders). This novel grading tool offers a simple, evidence-based device to improve recognition of heat-related illness in dogs and promote improved decision-making for earlier interventions such as cooling and hospitalisation. This could improve outcomes and protect the welfare of dogs in the face of rising global temperatures.

Demographic Changes in UK Rescue Centre Dog Population between 2014 and 2018.

Rescue centers remain a common means of rehoming a dog. There is a paucity of research into the composition of rescue center populations and its potential reflection of increased popularity of brachycephalic breeds. The study investigated changes in rescue center demographics from 2015 to 2018, compared to the wider dog population. Dogs on 16 rehoming centers' websites were recorded weekly from June 2015 for 8 weeks and replicated from June 2018. Data were collected on 1793 dogs across the centers. Over 50% of which were classified as purebred in both years. Over 80% of the dogs were categorized into 24 breeds or breed crosses. Dogs categorized as brachycephalic increased from 24 (2.76%) in 2015 to 48 (5.19%) in 2018. Subadult dogs (3-4 years) were most prevalent in both years. While sex, breed type, and age of the rehoming center population has remained relatively stable, breeds are changing. Whilst low, brachycephalic numbers doubled in 3 years, mirroring their rising popularity within the UK, impacting on rehoming centers and prospective new owners with additional costs of brachycephalic obstructive airway syndrome surgery.

Understanding the Impact of Scale Height on the Kinetics and Kinematics of Dogs in Working Trials.

Working trials is a canine discipline that originated from police and military dog work. One aspect of working trials competition is for a dog to "scale" a 6ft high wooden wall. Concern has been raised in other canine disciplines that landing forces after traversing jumps may lead to soft tissue injuries. There is a paucity of research into the impact of scale height on peak vertical landing force (PVF) in dogs participating in working trials. The aim of this work was to determine whether an alteration in scale height impacts PVF and apparent joint angulation on landing. Twenty-one dogs who regularly competed in working trials traversed the scale at three different heights; 6ft (full height), 5.5ft and 5ft. Changes in PVF, apparent carpal and shoulder joint angulation and duration of landing were analyzed using general linear mixed models. Dogs weighing >25 kg had greater PVF at 6ft than at 5ft (p < 0.05). There was no effect of scale height on PVF in dogs <25kg. Duration of landing was longer at 5ft than 5.5ft (p < 0.001) and 6ft (p < 0.001). Apparent carpus angle on landing was smaller at 6ft than 5ft (p < 0.05) and 5.5ft (p < 0.05) for dogs <25 kg. Apparent carpus angle on landing did not differ at any height for dogs >25 kg (p > 0.05). Apparent shoulder angle was not affected by scale height for any dogs (p > 0.05). There was considerable variation in the study population, but this research indicates that when the scale height was lowered to 5.5ft dogs had reduced PVF and less compressed joint angles on landing. When the scale height was lowered to 5ft they altered their traversing style and greater compression and increased PVF was seen. Evidence-based approaches to canine working trials are important to ensure minimum impacts on physical health and welfare of participating dogs, in terms of risk of injury in both competition and training. Based on these findings it is recommended that the maximum height of the scale is reviewed for training and competitive purposes, to ensure minimal impacts on the health of competing dogs, while maintaining the level of competitive challenge.

Understanding impacts of zoo visitors: Quantifying behavioural changes of two popular zoo species during COVID-19 closures.

Visitors are normally a prominent and constant feature in a zoo animals' environment with more than 700 million people visiting zoos and aquariums worldwide, annually. Animal-visitor interactions can be enriching and stimulating and are now considered within the Five Domains of animal welfare assessment. Zoo closures as a result of COVID-19 provided a unique opportunity to monitor the impact of abrupt and prolonged removal of visitors on two popular zoo species. Data were collected at four facilities (n = 3 slender-tailed meerkats, n = 1 African penguin) during COVID-19 zoo closures and up to one month following reopening to the public. Meerkats showed increased positive social interactions, increased alert behaviours, and reduced environmental interactions in the first month post-opening, as compared to closure periods. They also used more of their enclosures during periods of closure and spent longer than would be expected in zones furthest from visitor viewing areas when facilities reopened. African penguins showed no behavioural change between open and closure periods. Enclosure usage during both observation periods was relatively even and no differences were observed in enclosure use between open and closure periods. These results will enable an advanced understanding of the impact that people have on the behaviour of zoo animals, which has ramifications for animals used in close encounters and other 'visitor experiences' in the future. Understanding relationships between animals and people is applicable in all managed animal settings. The results from this study are of practical use in managing visitor access to animals moving forwards, including enclosure location and design, to ensure a positive visitor experience that does not negatively impact animal behaviour.

Drugs, dogs, and driving: the potential for year-round thermal stress in UK vehicles.

Background: Dogs are regularly transported or housed in vehicles, with guidelines for housing dogs suggesting that the ambient temperature should be maintained between 15°C and 24°C. Veterinary drugs are routinely stored and carried in vehicles providing ambulatory veterinary care. Non-refrigerated medications typically require storage between 8°C and 25°C. Aim: This study aims to investigate the potential for thermal stress associated with vehicular storage and transportation of drugs and dogs in a temperate climate, such as the United Kingdom. Methods: The study used data loggers to continuously record internal temperatures of four vehicles at 15-minute intervals over a two-year period, to investigate the effect of seasonality and time of day on the internal car temperature. Results: The internal car temperature ranged from -7.4°C to 54.5°C during the study period. Temperatures fell below 8°C every month, except June and July. The internal car temperature exceeded typical drug storage recommendations (>25°C) during every month, and exceeded the canine thermoneutral zone (>35°C) from April to September. Peak temperatures occurred between 14:00 and 17:00 hours. Conclusion: The results demonstrate the year-round potential for thermal stress of both dogs and drugs left in cars. Public awareness campaigns highlighting the risks of leaving dogs in hot cars are typically launched in late spring, but should consider launching earlier in light of these findings. Veterinary surgeons transporting drugs should take measures to ensure that drugs are stored within the manufacturer's temperature range year-round. This will limit the potential for drug degradation and decreased efficacy.

Dogs Don't Die Just in Hot Cars-Exertional Heat-Related Illness (Heatstroke) Is a Greater Threat to UK Dogs.

Heat-related illness will affect increasing numbers of dogs as global temperatures rise unless effective mitigation strategies are implemented. This study aimed to identify the key triggers of heat-related illness in dogs and investigate canine risk factors for the most common triggers in UK dogs. Using the VetCompassTM programme, de-identified electronic patient records of 905,543 dogs under primary veterinary care in 2016 were reviewed to identify 1259 heat-related illness events from 1222 dogs. Exertional heat-related illness was the predominant trigger (74.2% of events), followed by environmental (12.9%) and vehicular confinement (5.2%). Canine and human risk factors appear similar; young male dogs had greater odds of exertional heat-related illness, older dogs and dogs with respiratory compromise had the greatest odds of environmental heat-related illness. Brachycephalic dogs had greater odds of all three types of heat-related illness compared with mesocephalic dogs. The odds of death following vehicular heat-related illness (OR 1.47, p = 0.492) was similar to that of exertional heat-related illness. In the UK, exertional heat-related illness affects more dogs, and kills more dogs, than confinement in a hot vehicle. Campaigns to raise public awareness about heat-related illness in dogs need to highlight that dogs don't die just in hot cars.

Incidence and risk factors for heat-related illness (heatstroke) in UK dogs under primary veterinary care in 2016.

As climate change causes global temperatures to rise, heat-related illness, a potentially fatal condition in dogs, will become an ever-greater threat. This study aimed to report the incidence, fatality and canine risk factors of heat-related illness in UK dogs under primary veterinary care in 2016. The VetCompassTM programme collects de-identified electronic patient records from UK veterinary practices for research. From the clinical records of 905,543 dogs under veterinary care in 2016, 395 confirmed heat-related illness events were identified. The estimated 2016 incidence of heat-related illness was 0.04% (95% CI 0.04-0.05%), with an event fatality rate of 14.18% (95% CI 11.08 - 17.96%). Multivariable analysis identified significant risk factors including breed (e.g. Chow Chow, Bulldog and French Bulldog), higher bodyweight relative to the breed/sex mean and being over two years of age. Dogs with a brachycephalic skull shape and dogs weighing over 50 kg were also at greater risk. As we move into an ever-warmer world, veterinary professionals may need to include resistance to heat-related illness amongst their rationales when advising owners on breed selection. Breeding for good respiratory function and maintaining a healthy bodyweight should be considered key welfare priorities for all dogs to limit the risk of heat-related illness.

Understanding Temporal Social Dynamics in Zoo Animal Management: An Elephant Case Study.

Zoo animal management procedures which lead to changes to social groups can cause disruption in social hierarchies and the temporary breakdown of social relationships. Animals have different roles in social networks. Understanding individual positions in social networks is important for effective management and ensuring positive welfare for all animals. Using elephants as a case study, the aim of this research was to investigate temporal social dynamics in zoo animals. Behavioural data were collected between January 2016 and February 2017 from 10 African and 22 Asian elephants housed at seven zoos and safari parks in the UK and Ireland. Social interactions were defined as positive physical, positive non-physical, negative physical or negative non-physical. Social network analysis explored social relationships including the fluidity of networks over time and dyadic reciprocity. Social interaction networks were found to be fluid but did not follow a seasonal pattern. Positive interaction networks tended to include the entire social group whereas negative interactions were restricted to specific individuals. Unbalanced ties were observed within dyads, suggesting potential inequalities in relationships. This could impact on individual experiences and welfare. This research highlights subtle temporal dynamics in zoo elephants with the potential for species-level differences. Similar temporal dynamics may also be present in other socially housed zoo species. This research thus provides evidence for the importance of understanding the social networks of zoo animals over longer periods of time. Understanding social networks enables pro-active and evidence-based management approaches. Further research should seek to identify the minimum sampling efforts for social networks in a range of species, to enable the implementation of regular monitoring of social networks and thus improve the welfare of social species under human care.