Target Trial Emulation: Does surgical versus non-surgical management of cranial cruciate ligament rupture in dogs cause different outcomes?

Target trial emulation applies design principles from randomised controlled trials to the analysis of observational data for causal inference and is increasingly used within human epidemiology. Using anonymised veterinary clinical data from the VetCompass Programme, this study applied the target trial emulation framework to determine whether surgical (compared to non-surgical) management for cranial cruciate ligament (CCL) rupture in dogs causes improved short- and long-term lameness and analgesia outcomes. The emulated target trial included dogs diagnosed with CCL rupture between January 1, 2019 and December 31, 2019 within the VetCompass database. Inclusion in the emulated trial required dogs aged ≥ 1.5 and < 12 years, first diagnosed with unilateral CCL rupture during 2019 and with no prior history of contralateral ligament rupture or stifle surgery. Dogs were retrospectively observed to have surgical or non-surgical management. Informed from a directed acyclic graph derived from expert opinion, data on the following variables were collected: age, breed, bodyweight, neuter status, insurance status, non-orthopaedic comorbidities, orthopaedic comorbidities and veterinary group. Inverse probability of treatment weighting (IPTW) was used to adjust for confounding, with weights calculated based on a binary logistic regression exposure model. Censored dogs were accounted for in the IPTW analysis using inverse probability of censoring weighting (IPCW). The IPCWs were combined with IPTWs and used to weight each dog's contribution to binary logistic regression outcome models. Standardized mean differences (SMD) examined the balance of covariate distribution between treatment groups. The emulated trial included 615 surgical CCL rupture cases and 200 non-surgical cases. The risk difference for short-term lameness in surgically managed cases (compared with non-surgically managed cases) was -25.7% (95% confidence interval (CI) -36.7% to -15.9%) and the risk difference for long-term lameness -31.7% (95% CI -37.9% to -18.1%). The study demonstrated the application of the target trial framework to veterinary observational data. The findings show that surgical management causes a reduction in short- and long-term lameness compared with non-surgical management in dogs.

Impacts of Puppy Early Life Experiences, Puppy-Purchasing Practices, and Owner Characteristics on Owner-Reported Problem Behaviours in a UK Pandemic Puppies Cohort at 21 Months of Age.

Problem behaviours are a leading cause of relinquishment and euthanasia of young dogs. Previous research has identified associations between owner-reported problem behaviours and risk factors, including how dogs were acquired as puppies, early socialisation experiences, and owners' experience levels. Puppies acquired during the 2020 phase of the UK COVID-19 pandemic ("Pandemic Puppies") were more likely to be exposed to many of these risk factors compared to puppies acquired in 2019; however, consequences for their adult behaviour are, as yet, unexplored. This study aimed to investigate the impact of these early-life and provenance-based risk factors, in addition to owner management strategies (including training methods) into early adulthood, upon adult dog behaviour aged 21 months. An online longitudinal cohort study of n = 985 Pandemic Puppies was conducted, recruited from a cohort of n = 4369 puppies originally surveyed in November-December 2020, which included data on how and why they were acquired and their socialisation/habituation experiences <16 weeks of age. Nearly all owners (96.7%) reported that their dog had exhibited at least one problem behaviour up to 21 months of age (median: 5; IQR: 3-7). Almost one third of dogs (30.9%) were reported to have displayed separation-related behaviours. Multivariable linear regression modelling revealed that owners reporting more problem behaviours were more likely to use multiple aversive training techniques (e.g., physical punishment), the use of which was notably high in this population (82.3%) compared to previous studies. Attendance at online puppy classes was the sole protective factor against owner use of aversive training methods. Almost one third of owners had underestimated how hard training their dog would be; this view was more likely among first-time owners. Urgent efforts are required to support this vulnerable population of dogs, including providing owner education regarding humane training techniques, to improve canine emotional health and avoid future relinquishment and/or behavioural euthanasia.

Target trial emulation: Do antimicrobials or gastrointestinal nutraceuticals prescribed at first presentation for acute diarrhoea cause a better clinical outcome in dogs under primary veterinary care in the UK?

Target trial emulation applies design principles from randomised controlled trials to the analysis of observational data for causal inference and is increasingly used within human epidemiology. Veterinary electronic clinical records represent a potentially valuable source of information to estimate real-world causal effects for companion animal species. This study employed the target trial framework to evaluate the usefulness on veterinary observational data. Acute diarrhoea in dogs was used as a clinical exemplar. Inclusion required dogs aged ≥ 3 months and < 10 years, presenting for veterinary primary care with acute diarrhoea during 2019. Treatment strategies were: 1. antimicrobial prescription compared to no antimicrobial prescription and 2. gastrointestinal nutraceutical prescription compared to no gastrointestinal nutraceutical prescription. The primary outcome was clinical resolution (defined as no revisit with ongoing diarrhoea within 30 days from the date of first presentation). Informed from a directed acyclic graph, data on the following covariates were collected: age, breed, bodyweight, insurance status, comorbidities, vomiting, reduced appetite, haematochezia, pyrexia, duration, additional treatment prescription and veterinary group. Inverse probability of treatment weighting was used to balance covariates between the treatment groups for each of the two target trials. The risk difference (RD) of 0.4% (95% CI -4.5% to 5.3%) was non-significant for clinical resolution in dogs treated with antimicrobials compared with dogs not treated with antimicrobials. The risk difference (RD) of 0.3% (95% CI -4.5% to 5.0%) was non-significant for clinical resolution in dogs treated with gastrointestinal nutraceuticals compared with dogs not treated with gastrointestinal nutraceuticals. This study successfully applied the target trial framework to veterinary observational data. The findings show that antimicrobial or gastrointestinal prescription at first presentation of acute diarrhoea in dogs causes no difference in clinical resolution. The findings support the recommendation for veterinary professionals to limit antimicrobial use for acute diarrhoea in dogs.

Is UK Puppy Purchasing Suffering a Long COVID Effect? Ongoing Negative Impacts of the COVID-19 Pandemic upon Puppy Purchase Motivations and Behaviours in 2021.

The COVID-19 pandemic led to a surge in acquisitions of puppies in the UK, dubbed the "Pandemic Puppy" phenomenon. In addition to an increased demand for puppies, widespread changes to both why and how puppies were purchased during this period compared to pre-pandemic 2019 purchases were documented, many of which threatened canine welfare (e.g., puppies being collected away from their place of birth, without seeing their mother). This study aimed to explore which changes to the pre-purchase and purchase motivations and behaviours of UK owners who purchased a puppy aged <16 weeks in the 2020 phase of the COVID-19 pandemic had persisted into 2021 or had returned to pre-pandemic 2019 levels. An online survey was conducted during February to April 2022 from which 2080 valid responses were analysed ("2021 puppies") and compared with previously collected data from comparable cohorts in 2019 (n = 1148, "2019 puppies") and 2020 (n = 4369, "Pandemic Puppies"). While the majority of the peak pandemic changes documented in 2020 had returned to their 2019 pre-pandemic baseline, others persisted into 2021. Multinomial logistic regression models revealed that the shifts during 2020 towards owners viewing their puppy pre-purchase over video calls or via video recordings/photos rather than in-person and towards collecting their puppy from outside of their breeders' property rather than inside had persisted into 2021 and had not returned to pre-pandemic levels. Year-on-year significant rises in the number of puppies sold with a passport were documented between 2019 and 2021, with over 1 in 10 2021 puppies having been sold with a passport, the figure more than doubling since 2019. An increasing number of these puppies sold with a passport were under the minimum legal age for import at sale. Going forward, these concerning changes require further monitoring and human behaviour change interventions to tackle, including increased buyer awareness but also legislative approaches to prevent the greatest harm.

Commonly diagnosed disorders in domestic cats in the UK and their associations with sex and age.

OBJECTIVES: The objectives of this study were to generate a robust evidence base on the prevalence of common disorders in cats and develop a deeper understanding of disorder associations with sex and age that could offer important opportunities for targeted veterinary care to improve feline health and welfare. METHODS: A random sample of 18,249 cats was obtained from 1,255,130 cats under primary care during 2019 within VetCompass, an epidemiological research programme based on anonymised primary care veterinary clinical records. All disorders recorded during 2019 were extracted and reported, and associations with sex and age were examined. RESULTS: The most prevalent disorders were periodontal disease (n = 2780 [15.2%], 95% confidence interval [CI] 14.72-15.76), obesity (n = 2114 [11.6%], 95% CI 11.12-12.06) and dental disease (n = 1502 [8.2%], 95% CI 7.84-8.64). Compared with male cats, females had an increased prevalence of poor quality of life, postoperative complications and hyperthyroidism, among others. Male cats had a higher prevalence of periodontal disease, road traffic accident (RTA) and obesity. Younger cats (<8 years) had an increased prevalence of cat bite abscess, flea infestation and RTA, while older cats (⩾8 years) had increased prevalence of lameness, cystitis and dental disease, among others. CONCLUSIONS AND RELEVANCE: These findings suggest that the veterinary profession needs to engage more effectively in informing owners on common preventable disorders (ie, obesity and dental disease). This new information can contribute to more targeted health surveillance and more effective veterinary interventions to promote improved health and welfare in pet cats. Large-scale collection and analysis of anonymised veterinary clinical records offer an important clinical resource for research.

An investigation into an outbreak of pancytopenia in cats in the United Kingdom.

BACKGROUND: In spring 2021 increasing numbers of cats presenting with severe pancytopenia were noted in United Kingdom (UK). OBJECTIVE: To describe process and outcome of the investigation performed into the outbreak of pancytopenia in cats. ANIMALS: Five hundred and eighty client owned cats that presented with severe bi- or pancytopenia of unknown cause. METHODS: Real-time data collection was performed by an online registration forum available to all veterinary surgeons in UK. Data collected included demographics, clinicopathological findings, diagnostic testing, dietary and drug history, outcome and COVID household status. Mycotoxicological feed analysis was performed on feed samples of 3 diets frequently mentioned in the database and 3 control diets. RESULTS: Five hundred and eighty cats presented to 378 veterinary practices were included for analysis. Case fatality rate was 63.3%. Dietary history was available for 544 (93.8%) cats, of which 500 (86%) were fed 1 of 3 diets (which were recalled midinvestigation). 54 (9.3%) cats were not fed a recalled product, with diet information unknown in 26 (4.5%) cats. Analysis of feed samples revealed concentrations of hematotoxic trichothecene T-2/HT-2 mycotoxins greater than recommended by the European Commission in 5/7 recalled diet samples but in none of control diet samples. The trichothecene mycotoxin diacetoxyscirpenol (DAS) was detectable in all recalled diet samples but not in any of control samples. CONCLUSION AND CLINICAL IMPORTANCE: Contaminated-feed induced trichothecene mycotoxicosis should be considered as a differential diagnosis for pancytopenia in cats.

Frequency, breed predispositions and other demographic risk factors for diagnosis of hypothyroidism in dogs under primary veterinary care in the UK.

BACKGROUND: Hypothyroidism is a commonly diagnosed endocrinopathy in dogs. This study aimed to investigate the frequency and risk factors for diagnosis of hypothyroidism in UK primary-care practice. Dogs diagnosed with hypothyroidism were identified by searching electronic patient records of primary-care practices participating in VetCompass. A cohort study design estimated one-year (2016) period prevalence and incidence risk for hypothyroidism. Multivariable binary logistic regression models were used to evaluate associations between demographic risk factors and hypothyroidism. RESULTS: From 905,553 dogs, 2,105 dogs were recorded with diagnosed hypothyroidism in 2016; 359 incident and 1,746 pre-existing, giving an annual prevalence of 0.23% (95% CI 0.22-0.24) and annual incidence risk of 0.04% (95% CI 0.04-0.04). Multivariable logistic regression identified 24 predisposed and nine protected breeds. Standard Doberman pinscher (odds ratio [OR] = 17.02, 95% CI 12.8-22.64), Tibetan terrier (11.25, 95% CI 8.27-15.32) and boxer (10.44, 95% CI 8.66-12.58) breeds showed high predisposition. Pug (OR 0.29, 95% CI 0.09-0.89), Yorkshire terrier (OR 0.38, 95% CI 0.24-0.59), Shih-tzu (OR 0.38, 95% CI 0.23-0.64) and Jack Russell terrier (OR 0.40, 95% CI 0.29-0.54) were the most protected breeds. Overall, being a purebred dog, being insured, having bodyweight above the breed-sex mean, increasing age, being neutered and rising adult bodyweight also showed increased odds being a dog living with a diagnosis of hypothyroidism. CONCLUSIONS: Several strong breed predispositions for diagnosis of hypothyroidism were identified that can assist with disorder prioritisation in ongoing efforts to improve breed health. Other risk factors were also identified that can assist veterinary surgeons during clinical work-up of suspected cases. Identification of novel evidence for protected breeds provides useful information for research into genetic mechanisms.

Ironing out the wrinkles and folds in the epidemiology of skin fold dermatitis in dog breeds in the UK.

Skin fold dermatitis (intertrigo) is an inflammatory process of closely apposing skin surfaces. Extreme conformations towards folded skin in many dog breeds are linked with higher risk. Using anonymised primary-care veterinary data from the VetCompass Programme, this study aimed to report the frequency, demographic risk factors and clinical management for skin fold dermatitis in the UK. Risk factor analysis used random effects multivariable logistic regression modelling. From a study population of 905,553 dogs, the one-year period prevalence in dogs overall was 0.37% (95% CI 0.35-0.39). Diagnosis was supported by laboratory testing in 4.21% cases. Systemic antibiosis was used in 42.30% cases. Compared with crossbreed dogs, the most highly predisposed breeds were English Bulldog (odds ratio [OR] 49.07, 95% CI 37.79-63.70), French Bulldog (OR 25.92, 95% CI 19.62-34.26,) and Pug (OR 16.27, 95% CI 12.20-21.69). The most protected breeds were Yorkshire Terrier (OR 0.14, 95% CI 0.03-0.56), Border Collie (OR 0.31, 95% CI 0.11-0.84), Jack Russell Terrier (OR 0.53, 95% CI 0.30-0.92) and Labrador Retriever (OR 0.57, 95% CI 0.35-0.93). This study adds further evidence to the welfare concerns around high popularity of dog breeds with extreme conformations. The three breeds with by far the highest odds of skin fold dermatitis represent an extreme brachycephalic conformation.

English Bulldogs in the UK: a VetCompass study of their disorder predispositions and protections.

BACKGROUND: The English Bulldog has risen sharply in popularity over the past decade but its distinctive and extreme conformation is linked to several serious health conditions. Using multivariable analysis of anonymised veterinary clinical data from the VetCompass Programme, this study compared the odds of common disorders between English Bulldogs and all remaining dogs in the UK during 2016. RESULTS: From 905,544 dogs under veterinary care during 2016, the analysis included a random sample of 2,662 English Bulldogs and 22,039 dogs that are not English Bulldogs. English Bulldogs had 2.04 times the odds of diagnosis with ≥ 1 disorder than dogs that are not English Bulldogs (95% confidence interval [CI] 1.85 to 2.25). At a specific-level of diagnostic precision, English Bulldogs had increased odds of 24/43 (55.8%) disorders. These included: skin fold dermatitis (odds ratio [OR] 38.12; 95% CI 26.86 to 54.10), prolapsed nictitating membrane gland (OR 26.79; 95% CI 18.61 to 38.58) and mandibular prognathism (OR 24.32; 95% CI 13.59 to 43.53). Conversely, English Bulldogs had significantly reduced odds of 6/43 (14.0%) disorders. These included: retained deciduous tooth (OR 0.02; 95% CI 0.01 to 0.17), lipoma (OR 0.06; 95% CI 0.01 to 0.40) and periodontal disease (OR 0.23; 95% CI 0.18 to 0.30). At a grouped-level of diagnostic precision, English Bulldogs had significantly increased odds of 17/34 (50.0%) disorders. These included: congenital disorder (OR 7.55; 95% CI 5.29 to 10.76), tail disorder (OR 6.01; 95% CI 3.91 to 9.24) and lower respiratory tract disorder (OR 5.50; 95% CI 4.11 to 7.35). Conversely, English Bulldogs had significantly reduced odds of 3/34 (8.8%) disorders. These were: dental disorder (OR 0.25; 95% CI 0.20 to 0.31), spinal cord disorder (OR 0.31; 95% CI 0.14 to 0.71) and appetite disorder (OR 0.43; 95% CI 0.20 to 0.91). CONCLUSIONS: These results suggest that the health of English Bulldogs is substantially lower than dogs that are not English Bulldogs and that many predispositions in the breed are driven by the extreme conformation of these dogs. Consequently, immediate redefinition of the breed towards a moderate conformation is strongly advocated to avoid the UK joining the growing list of countries where breeding of English Bulldogs is banned.

The English Bulldog has risen sharply in popularity over the past decade in the UK. However, its distinctive and extreme conformation has raised concerns because many of these physical features render the breed prone to serious health conditions. There are increasing international efforts to either reform the breed towards a more moderate conformation or, in the absence of such change, to ban the breeding of these dogs on welfare grounds.This VetCompass study explored random samples of anonymised veterinary clinical records from 2,662 English Bulldogs and 22,039 dogs that are not English Bulldogs from an overall population of 905,544 dogs under veterinary care during 2016 in the UK to identify all health disorders recorded for each dog during 2016. The most common disorders in each group were identified and the risks for the most common disorders overall was compared between the English Bulldogs and dogs that are not English Bulldogs.English Bulldogs were younger (2.65 years vs 4.42 years) and heavier (25.55kg vs 13.54kg) than dogs that are not English Bulldogs. English Bulldogs had 2.04 times the risk of diagnosis with at least one disorder during 2016 compared with dogs that are not English Bulldogs. English Bulldogs had increased risk for 24/43 (55.8%) disorders compared to dogs that are not English Bulldogs. The disorders with the highest risk in English Bulldogs included skin fold dermatitis (× 38.12), prolapsed nictitating membrane gland [cherry eye] (× 26.79), protruding lower jaw (× 24.32), brachycephalic obstructive airway syndrome [BOAS] (× 19.20) and interdigital cyst (× 12.96). Conversely, English Bulldogs had significantly reduced risk of 6/43 (14.0%) disorders compared to dogs that are not English Bulldogs. These included: retained deciduous [baby] tooth (× 0.02), lipoma [fatty mass] (× 0.06), dental disease (× 0.23), itchy skin (× 0.25) and flea infestation (× 0.40).The results of this study suggest that the overall health of the English Bulldog is much lower than dogs that are not English Bulldogs. Many of the disorder predispositions reported in this study are intrinsically related to the extreme conformation of English Bulldogs. Redefining the body-shape of the breed away from its current extreme conformation and towards a moderate conformation is advocated for urgent action to avoid the UK joining the growing list of countries where breeding of English Bulldogs is banned.

Health of Pug dogs in the UK: disorder predispositions and protections.

BACKGROUND: Pugs are a brachycephalic dog breed that has become phenomenally popular over recent decades. However, there is growing concern about serious health and welfare issues in the breed. To augment the evidence-base on the comparative health of Pugs, this study aimed to compare the odds of common disorders between Pugs and all remaining dogs under primary veterinary care in the UK during 2016. A cross-sectional study design of VetCompass clinical records was used to estimate the one-year (2016) period prevalence for the disorders most commonly diagnosed in Pugs and non-Pugs. Risk factor analysis applied multivariable logistic regression modelling methods to compare the odds of 40 common disorders between Pugs and non-Pugs. RESULTS: From a study population of 905,544 dogs, the analysis included random samples of 4308 Pugs and 21,835 non-Pugs. Pugs were younger (2.36 years, range 0.07-16.24 vs 4.44 years, range 0.01-20.46, p <  0.001) and lighter (8.95 kg, range 5.00-13.60 vs. 14.07 kg, range 1.41-85.00, p <  0.001) than non-Pugs. Pugs had 1.86 (95% confidence interval [CI] 1.72 to 2.01) times the adjusted odds of diagnosis with ≥1 disorder than non-Pugs. Pugs had significantly increased adjusted odds for 23/40 (57.5%) common disorders. These included: brachycephalic obstructive airway syndrome (odds ratio [OR] 53.92; 95% CI 36.22 to 80.28), stenotic nares (OR 51.25; 95% CI 24.93 to 105.37) and corneal ulceration (OR 13.01; 95% CI 10.50 to 16.11). Conversely, Pugs had significantly reduced adjusted odds of 7/40 (17.5%) common disorders compared to non-Pugs. These included: heart murmur (OR 0.23; 95% 0.13 to 0.14), lipoma (OR 0.24; 95% CI 0.11 to 0.55) and aggression (OR 0.31; 95% CI 0.21 to 0.47). CONCLUSIONS: The current study highlights that predispositions outnumber protections between Pugs and non-Pugs for common disorders, suggesting some critical health welfare challenges to overcome for Pugs. Highly differing heath profiles between Pugs and other dogs in the UK suggest that the Pug has diverged substantially from mainstream dog breeds and can no longer be considered as a typical dog from a health perspective.

Pugs have become phenomenally popular in the UK over recent decades. The breed has a flat-faced look (brachycephalic) that many humans find highly attractive and 'cute' but this flat face is also linked to several serious health problems. Consequently, there is growing concern about the welfare issues associated with the popularity and health issues of Pugs. To get a better overall perspective on the health of Pugs, this study aimed to compare the risks of common disorders between Pugs and all remaining dogs.The study collected clinical information from first opinion veterinary practices in the UK that were participating in VetCompass. Dogs were grouped as either Pugs or non-Pugs. Information was gathered from the clinical records on all disorders diagnosed in each group during 2016 and a list of the most common disorders in each group was generated.From 905,544 dogs in the overall study, there were 16,218 (1.79%) Pugs and 889,326 (98.21%) non-Pugs. Pugs (2.36 years, interquartile range [IQR] 1.16­4.53) were generally younger than non-Pugs (4.44 years, IQR 1.90­8.12). Pugs (8.95 kg, IQR 7.80­10.17) were also generally lower in bodyweight than non-Pugs (14.07 kg, IQR 8.15­25.20). From a combined list of 40 common disorders among both groups of dogs, Pugs had increased risk for 23 (57.5%) but had reduced risk for 7 (17.5%) disorders compared to non-Pugs. The disorders with the highest relative risk in Pugs included brachycephalic obstructive airway syndrome (BOAS) (× 53.92 risk), narrowed nostrils (× 51.25), eye ulceration (× 13.01), and skin fold infection (× 10.98). Disorders with the lowest relative risk in Pugs included heart murmur (× 0.23), fatty lump (× 0.24), aggression (× 0.31), and wounds (× 0.53).The study provides a broad evidence base on the positive and negative aspects of the health of Pugs. Disease predispositions were more common than disease protections, confirming the hypothesis that there are many critical health-related welfare challenges to overcome for Pugs. The widely differing health profiles between Pugs and other dogs in the UK suggest that the Pug has now diverged to such an extent from mainstream dog breeds that it can no longer be considered as a typical dog from a health perspective.

Life tables of annual life expectancy and mortality for companion dogs in the United Kingdom.

A life table is a tabulated expression of life expectancy and mortality-related information at specified ages in a given population. This study utilised VetCompass data to develop life tables for the UK companion dog population and broken down by sex, Kennel Club breed group, and common breeds. Among 30,563 dogs that died between 1st January 2016 and 31st July 2020, life expectancy at age 0 was 11.23 [95% confidence interval (CI): 11.19-11.27] years. Female dogs (11.41 years; 95% CI: 11.35-11.47) had a greater life expectancy than males (11.07 years; 95% CI: 11.01-11.13) at age 0. Life tables varied widely between breeds. Jack Russell Terrier (12.72 years; 95% CI: 12.53-12.90) and French Bulldog (4.53 years; 95% CI: 4.14-5.01) had the longest and shortest life expectancy at age 0, respectively. Life tables generated by the current study allow a deeper understanding of the varied life trajectory across many types of dogs and offer novel insights and applications to improve canine health and welfare. The current study helps promote further understanding of life expectancy, which will benefit pet owners and the veterinary profession, along with many other sectors.

Pandemic Puppies: Demographic Characteristics, Health and Early Life Experiences of Puppies Acquired during the 2020 Phase of the COVID-19 Pandemic in the UK.

The UK recorded sharp rises in puppy purchasing during the 2020 phase of the COVID-19 pandemic, with many first-time dog owners purchasing puppies to improve their mental health during this challenging period. Government restrictions on movement and social interaction during the pandemic led to animal welfare concerns over puppies' reduced time-sensitive exposures to key environmental and social stimuli during their critical developmental period. This study aimed to compare demographics, health and early-life experiences of puppies purchased and brought home < 16 weeks of age between 23 March−31 December 2020 ("Pandemic Puppies"), with dogs purchased and brought home < 16 weeks during the same date period in 2019 ("2019 puppies"). An online survey of UK-based puppy owners was conducted between 10 November and 31 December 2020 with valid responses representing 5517 puppies (Pandemic Puppies: n = 4369; 2019 puppies: n = 1148). Multivariable logistic regression modelling revealed that Pandemic Puppies were less likely to have attended puppy training classes (67.9% 2019 vs. 28.9% 2020; p < 0.001) or had visitors to their home (94.5% 2019 vs. 81.8% 2020; p < 0.001) aged < 16 weeks compared with 2019 puppies. Fewer Pandemic Puppies underwent veterinary checks prior to purchase than 2019 puppies (2019: 91.3% vs. 2020: 87.4%; p < 0.001), but more were sold with a passport (2019: 4.1% vs. 2020: 7.1%; p < 0.001). Pandemic Puppies were significantly more likely to be 'Designer Crossbreeds' (2019: 18.8% vs. 2020: 26.1%; p < 0.001) and less likely to be Kennel Club registered than 2019 puppies (2019: 58.2% vs. 2020: 46.2%; p < 0.001). Greater support from veterinary and animal behavioural professionals is likely needed to ameliorate the health and behavioural impacts of growing up in a pandemic upon this vulnerable population.

Veterinary drug therapies used for undesirable behaviours in UK dogs under primary veterinary care.

Undesirable behaviours (UBs) in dogs are common and important issues with serious potential welfare consequences for both the dogs and their owners. This study aimed to investigate the usage of drug therapy for UBs in dogs and assess demographic risk factors for drug-prescribed UBs within the dog population under primary-care veterinary care in the UK in 2013. Dogs receiving drug therapy for UB were identified through the retrospective analysis of anonymised electronic patient records in VetCompass™. Risk factor analysis used multivariable logistic regression modelling. The study population comprised 103,597 dogs under veterinary care in the UK during 2013. There were 413 drug-prescribed UBs recorded among 404 dogs. The prevalence of dogs with at least one UB event treated with a drug in 2013 was 0.4%. Multivariable modelling identified 3 breeds with increased odds of drug-prescribed UB compared with crossbred dogs: Toy Poodle (OR 2.75), Tibetan Terrier (OR 2.68) and Shih-tzu (OR 1.95). Increasing age was associated with increased odds of drug-prescribed UB, with dogs ≥ 12 years showing 3.1 times the odds compared with dogs < 3 years. Neutered males (OR 1.82) and entire males (OR 1.50) had increased odds compared with entire females. The relatively low prevalence of dogs with at least one UB event that was treated with a drug in 2013 could suggest that opportunities for useful psychopharmaceutical intervention in UBs may be being missed in first opinion veterinary practice. While bodyweight was not a significant factor, the 3 individual breeds at higher odds of an UB treated with a behaviour modifying drug all have a relatively low average bodyweight. The current results also support previous research of a male predisposition to UBs and it is possible that this higher risk resulted in the increased likelihood of being prescribed a behaviour modifying drug, regardless of neuter status.

Breed and conformational predispositions for prolapsed nictitating membrane gland (PNMG) in dogs in the UK: A VetCompass study.

BACKGROUND: Prolapsed nictitating membrane gland (PNMG) is the most common disorder of the third eyelid in dogs. However, the epidemiology of PNMG in the wider dog population remains understudied. METHODS: Using de-identified clinical data from the VetCompass Programme, this cohort study aimed to report the prevalence, demographic and breed-related risk factors of PNMG in dogs attending UK primary care veterinary practices in 2016. RESULTS: There were 1,802 PNMG cases identified from 905,543 dogs, yielding an annual prevalence of 0.20% (95% confidence interval (CI) 0.19-0.21). The median age at first diagnosis was 0.63 years (IQR 0.33-1.98, range 0.11-18.00). Dogs aged under 1 year had 10.82 times the odds (95% CI 9.17-12.76) compared with dogs aged from 2 to under 4 years. Neutered animals had higher odds than entire animals within both sexes. Breeds with the highest odds of PNMG compared with crossbred dogs included Neapolitan Mastiff (odds ratio (OR) 34.26, 95%CI 15.92-73.75), English Bulldog (OR 24.08, 95% CI 20.62-28.13), Cane Corso (OR 14.66, 95% CI 8.18-26.28), Lhasa Apso (OR 12.37, 95% CI 10.26-14.92) and American Cocker Spaniel (OR 11.57, 95% CI 5.59-23.96). Purebred dogs had 1.43 times the odds (95% CI 1.26-1.63) of PNMG compared with crossbreed dogs. Breeds with brachycephalic skull conformation had 6.71 times the odds (95%CI 5.89-7.64) compared with breeds with mesocephalic skull conformation. Insured dogs had 1.89 times the odds (95% CI 1.65-2.16) compared with uninsured dogs. CONCLUSIONS: This study reports the largest cohort of primary-care PNMG cases assembled to date. The results showing young age at diagnosis along with the breed, purebred and brachycephalic skull conformation predispositions suggest a hereditary involvement in PNMG development. These results may help to guide breeding strategies to reduce the prevalence of PNMG and improve welfare in predisposed individuals.

French Bulldogs differ to other dogs in the UK in propensity for many common disorders: a VetCompass study.

BACKGROUND: The French Bulldog is a highly popular dog breed but is linked with many serious health issues. A holistic view of breed health in French Bulldogs would assist efforts to appreciate the overall health strengths and weaknesses in the French Bulldog and to take appropriate steps to mitigate these. Based on random sampling of French Bulldogs and non-French Bulldogs under primary veterinary care during 2016 within the VetCompass Programme, a cohort study design was used to estimate the one-year (2016) period prevalence of the most commonly diagnosed disorders in each group. Risk factor analysis used multivariable logistic regression modelling methods. RESULTS: The analysis included 2,781 French Bulldogs and 21,850 non-French Bulldogs. French Bulldogs were younger (1.51 years, IQR 0.86 - 2.77 vs. 4.48 years, IQR 1.94 - 8.14) (p < 0.001) and lighter (12.45 kg, IQR 11.00 - 14.03 versus 13.80 kg, IQR 8.10 - 25.12) (p < 0.001) than non-French Bulldogs. Of 43 common specific-level disorders across both groups, French Bulldogs had significantly increased adjusted odds of 20/43 (46.5 %) disorders and significantly reduced adjusted odds of 11/43 (25.6 %) disorders compared to non-French Bulldogs. Highly predisposed disorders in French Bulldogs included stenotic nares (OR 42.14; 95 % CI 18.50 to 95.99; p < 0.001), Brachycephalic Obstructive Airway Syndrome (OR 30.89; 95 % CI 20.91 to 45.64; p < 0.001), aural discharge (OR 14.40; 95 % CI 9.08 to 22.86; p < 0.001), skin fold dermatitis (OR 11.18; 95 % CI 7.19 to 17.40; p < 0.001) and dystocia (OR 9.13; 95 % CI 5.17 to 16.13; p < 0.001). At a grouped-level of diagnostic precision, French Bulldogs had increased adjusted odds of 12/32 (37.5 %) disorders and reduced adjusted odds of 6/32 (18.8 %) disorders compared to non-French Bulldogs. CONCLUSIONS: These results identified ultra-predispositions with worryingly higher odds in French Bulldogs for several disorders, suggesting that the health of French Bulldogs has diverged substantially from, and may be lower than, the health of the wider non-French Bulldog population. Many of these predispositions are closely associated with the conformational extremes that define the French Bulldog breed. Shifting the typical conformation of the French Bulldog population towards a more moderate phenotype is proposed as a logical opportunity to reduce the serious health issues endemic in the French Bulldog breed.

The French Bulldog is currently a hugely popular dog breed in the UK. However, the breed is linked with a range of serious health issues. Using veterinary clinical data from the VetCompass Programme at the Royal Veterinary College, this study aimed to compare the frequency of common disorders in French Bulldogs against that of all remaining dogs to identify health strengths and weaknesses in French Bulldogs. This overall view of breed health can assist owners, breeders and veterinarians to take appropriate actions to improve the health of French Bulldogs.From an overall population of 905,544 dogs, random samples of 2,781 French Bulldogs and 21,850 non-French Bulldogs were included in the analysis. French Bulldogs were younger (1.51 years versus 4.48 years) and lighter (12.45 kg versus 13.80 kg) than non-French Bulldogs. French Bulldogs had increased risk of 20/43 (46.5 %) specific disorders and decreased risk of 11/43 (25.6 %) specific disorders compared to non-French Bulldogs. The disorders with greatest relative risk in French Bulldogs compared to non-French Bulldogs were narrowed nostrils (x 42.14), Brachycephalic Obstructive Airway Syndrome (x 30.89), ear discharge (x 14.40), skin fold dermatitis (x 11.18) and difficulty giving birth [dystocia] (x 9.13). When the disorders were grouped into broad disease categories, French Bulldogs had increased risk of 12/32 (37.5 %) disorder groups and reduced risk of 6/32 (18.8 %) disorder groups compared to non-French Bulldogs.This study suggests that the health of French Bulldogs is very different, and largely much poorer, that the health of the wider non-French Bulldog population. Many of these differences are closely associated with the extreme body shape that defines the French Bulldog breed. Shifting the body shape of French Bulldogs to become more moderate, and hence less extreme, is proposed as a logical opportunity to reduce the current serious and common health issues in the French Bulldog breed.

Reporting the epidemiology of aural haematoma in dogs and proposing a novel aetiopathogenetic pathway.

To evaluate the incidence and risk factors for aural haematoma in dogs under primary veterinary care in the UK. A cohort study design. Dogs diagnosed with aural haematoma during 2016 were identified from the VetCompass database. Univariable and multivariable logistic regression modelling were used for risk factor analysis. There were 2,249/905,554 dogs diagnosed with aural haematoma during 2016. The estimated one-year incidence risk for aural haematoma was 0.25% (95% confidence interval 0.24-0.26). After accounting for confounding factors, 14 breeds showed increased odds and 20 breeds showed reduced odds of aural haematoma compared with crossbred dogs. Breeds with the highest odds included Bull Terrier (OR 7.42, 95% confidence interval 4.39-12.54), Saint Bernard (OR 7.28, 95% confidence interval 3.58-14.81) and French Bulldog (OR 6.95, 95% confidence interval 5.55-8.70). Increasing age, increasing bodyweight and breeds with V-shaped drop and semi-erect ear carriage also showed increased odds of aural haematoma. Associations between ear carriage within breeds and the risk of aural haematoma suggest that trauma along the line of cartilage folding within V-shaped and semi-erect ears may trigger aural haematoma. New knowledge of key breed predispositions will contribute to improved breed health control strategies.

Frequency and predisposing factors for canine otitis externa in the UK - a primary veterinary care epidemiological view.

BACKGROUND: Otitis externa is a commonly diagnosed disorder in dogs and can carry a high welfare impact on affected animals. This study aimed to report the prevalence and explore the role of breed and aural conformation as predisposing factors for canine otitis externa in the UK. The study used a cohort design of dogs under UK primary veterinary care at clinics participating in the VetCompass Programme during 2016. Risk factor analysis used multivariable logistic regression modelling. RESULTS: The study included a random sample of 22,333 dogs from an overall population of 905,554 dogs under veterinary care in 2016. The one-year period prevalence of otitis externa was 7.30% (95% confidence interval [CI]: 6.97 to 7.65). Breed and ear carriage were the highest ranked risk factors. Compared with crossbred dogs, sixteen breed types showed increased odds, including: Basset Hound (odds ratio [OR] 5.87), Chinese Shar Pei (OR 3.44), Labradoodle (OR 2.95), Beagle (OR 2.54) and Golden Retriever (OR 2.23). Four breeds showed protection (i.e. reduced odds) of otitis externa: Chihuahua (OR 0.20), Border Collie (OR 0.34), Yorkshire Terrier (OR 0.49) and Jack Russell Terrier (OR 0.52). Designer breed types overall had 1.63 times the odds (95% CI 1.31 to 2.03) compared with crossbred dogs. Compared with breeds with erect ear carriage, breeds with pendulous ear carriage had 1.76 times the odds (95% CI 1.48 to 2.10) and breeds with V-shaped drop ear carriage had 1.84 times the odds (95% CI 1.53 to 2.21) of otitis externa. CONCLUSIONS: Breed itself and breed-associated ear carriage conformation are important predisposing factors for canine otitis externa. Greater awareness of these associations for both predisposed and protected breeds could support veterinary practitioners to promote cautious and low-harm approaches in their clinical advice on preventive care for otitis externa, especially in predisposed breeds.

Otitis externa is a common and often painful condition of the ears of dogs. The probability of otitis externa varies widely between dogs depending on their tendency towards other skin problems such as allergic skin disease. However, breed-related anatomical features such as the degree and point of folding of the ear flap or the overall size of the dog can act to further predispose towards otitis externa. Greater understanding of these predisposing factors could lead to opportunities for breeders to breed away from predisposing features and also help owners and veterinarians to predict which dogs are most at risk of this painful condition.Veterinarians record clinical notes when dogs visit for veterinary care, and these clinical notes can act as a rich source of information on the health of these dogs. This study accessed anonymised clinical records of almost a million dogs in the UK to identify dogs diagnosed with otitis externa. The breed, age, bodyweight and other information available on these dogs were used to explore why certain dog types were predisposed to otitis externa.A random sample of 22,333 dogs was selected for analysis. Of these, 7.30% (over 7 in a hundred) were diagnosed with otitis externa in a single year. There were 16 breeds with higher risk of otitis externa compared with crossbred dogs. Breeds with the highest risk were Basset Hound (× 5.87), Chinese Shar Pei (× 3.44), Labradoodle (× 2.95), Beagle (× 2.54) and Golden Retriever (× 2.23). Four breeds showed reduced risk: Chihuahua (× 0.20), Border Collie (× 0.34), Yorkshire Terrier (× 0.49) and Jack Russell Terrier (× 0.52). Breeds with pendulous ear carriage (× 1.76) and V-shaped drop ear carriage (× 1.84) had higher risk of otitis externa compared with breeds with erect ear carriage.Breed itself and also breed-associated ear carriage conformation are associated with differing probability of otitis externa in dogs. Better understanding about how these factors affect the probability of otitis externa in dogs can help veterinary practitioners to promote cautious and low-harm approaches to preventing otitis externa (e.g., by advocating ear cleaning with a dry paper cloth, judicious use of ear cleaners with antimicrobial properties and avoidance of overzealous ear-cleaning) and can also assist breeders to breed away from features of dogs that predispose to otitis externa.

Pandemic Puppies: Characterising Motivations and Behaviours of UK Owners Who Purchased Puppies during the 2020 COVID-19 Pandemic.

Widespread media reports suggest that unusually high numbers of the public purchased, or sought to purchase, puppies following the first 'lockdown' phase of the COVID-19 pandemic in the UK, dubbed "Pandemic Puppies". This study aimed to explore this phenomenon by comparing pre-purchase motivations and behaviours, and purchase behaviours of UK owners purchasing puppies aged < 16 weeks from 23 March 2020-31 December 2020 with those of owners who purchased puppies during the same date-period in 2019. An online survey was conducted during November-December 2020, from which 5517 valid responses were analysed (2019 puppies: n = 1148; 2020 'Pandemic Puppies': n = 4369). Over 1 in 10 Pandemic Puppy owners had not considered purchasing a puppy before the pandemic, and 2 in 5 felt their decision to purchase a puppy had been influenced by the pandemic, most commonly by having more time to care for a dog (86.7%). Multivariable logistic regression models revealed that Pandemic Puppy owners were more likely to be first-time dog owners and have children in their household, were less likely to seek out a breeder that performed health testing on their breeding dog(s) or view their puppy in-person, and were more likely to pay a deposit without seeing their puppy. At purchase, Pandemic Puppies were more likely to be younger, delivered or collected from outside their breeders' property, seen without their littermates, and cost > £2000 compared with 2019 puppies. Changes in puppy purchasing during the pandemic raise welfare concerns for this unique population, including relinquishment, behavioural problems and poor health.

Disorder predispositions and protections of Labrador Retrievers in the UK.

The Labrador Retriever is one of the most popular dog breeds worldwide, therefore it is important to have reliable evidence on the general health issues of the breed. Using anonymised veterinary clinical data from the VetCompass Programme, this study aimed to explore the relative risk to common disorders in the Labrador Retriever. The clinical records of a random sample of dogs were reviewed to extract the most definitive diagnoses for all disorders recorded during 2016. A list of disorders was generated, including the 30 most common disorders in Labrador Retrievers and the 30 most common disorders in non-Labrador Retrievers. Multivariable logistic regression was used to report the odds of each of these disorders in 1462 (6.6%) Labrador Retrievers compared with 20,786 (93.4%) non-Labrador Retrievers. At a specific-level of diagnostic precision, after accounting for confounding, Labrador Retrievers had significantly increased odds of 12/35 (34.3%) disorders compared to non-Labrador Retrievers; osteoarthritis (OR 2.83) had the highest odds. Conversely, Labrador Retrievers had reduced odds of 7/35 (20.0%) disorders; patellar luxation (OR 0.18) had the lowest odds. This study provides useful information about breed-specific disorder predispositions and protections, which future research could evaluate further to produce definitive guidance for Labrador Retriever breeders and owners.

Proportion and risk factors for death by euthanasia in dogs in the UK.

The loss of a pet can be particularly distressing for owners, whether the method of death is euthanasia or is unassisted. Using primary-care clinical data, this study aimed to report the demographic and clinical factors associated with euthanasia, relative to unassisted death, in dogs. Method of death (euthanasia or unassisted) and clinical cause of death were extracted from a random sample of 29,865 dogs within the VetCompass Programme from a sampling frame of 905,544 dogs under UK veterinary care in 2016. Multivariable logistic regression modelling was used to evaluate associations between risk factors and method of death. Of the confirmed deaths, 26,676 (89.3%) were euthanased and 2,487 (8.3%) died unassisted. After accounting for confounding factors, 6 grouped-level disorders had higher odds in euthanased dogs (than dogs that died unassisted), using neoplasia as the baseline. The disorders with greatest odds included: poor quality of life (OR 16.28), undesirable behaviour (OR 11.36) and spinal cord disorder (OR 6.00). Breed, larger bodyweight and increasing age were additional risk factors for euthanasia. The results highlight that a large majority of owners will face euthanasia decisions and these findings can support veterinarians and owners to better prepare for such an eventuality.