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.

English Cocker Spaniels under primary veterinary care in the UK: disorder predispositions and protections.

BACKGROUND: The English Cocker Spaniel (ECS) is one of the most popular dog breeds in the UK but information on disorder predisposition and protection is limited. Using anonymised veterinary clinical data from the VetCompass™ Programme, this study aimed to compare disorder predisposition and protection between the ECS and the remaining dogs under primary veterinary care in the UK during 2016. Electronic patient records for random samples of ECS and non-ECS were reviewed. The most common disorders diagnosed during 2016 were extracted and compared using multivariable logistic regression, controlling for confounders. RESULTS: The analysis included random samples of 2510/10,313 (24.3%) ECS and 7813/326,552 (2.39%) non-ECS. After accounting for confounding by age, sex, bodyweight within breed-sex, insurance status and veterinary practice group, the ECS had increased odds of 21/43 (48.85%) disorders at fine-level precision, with highest odds for aural discharge (odds ratio (OR) 14.66, 95% confidence interval (CI): 7.73-30.90, P <  0.001) and keratoconjunctivitis sicca (OR 7.64, 95% CI: 4.33-14.14, P <  0.001) and lowest odds for atopic dermatitis (OR 0.14, 95% CI: 0.05-0.31, P <  0.001) and allergy (OR 0.14, 95% CI: 0.06-0.28, P <  0.001). CONCLUSIONS: This study provides evidence for strong predisposition to aural and ocular disorders and protection from hypersensitivity disorders in the ECS. These results can aid dog owners, breeders, and veterinarians to better monitor health in ECS, and promote earlier diagnosis with improved prognosis. Further, the results can help breeding organisations establish key priorities the health-based reforms of the ECS.

Demography, common disorders and mortality of Shih Tzu dogs under primary veterinary care in the UK.

BACKGROUND: Shih Tzus are a popular dog breed in the UK although there is relatively little reported information on their health. This study aimed to characterise the demography, common disorders and mortality of Shih Tzus under primary veterinary care during 2016 in the UK using de-identified clinical records from the VetCompass™ Programme. RESULTS: The study population of 336,865 dogs under veterinary care during 2016 included 11,082 Shih Tzus (3.3%). The median age was 4.1 years (IQR: 2.1-7.1, range: 0.3-20.4) and mean adult bodyweight was 7.9 kg (SD: 1.9 kg). Annual proportional births increased from 2.2% of all dog births in 2005 to 3.8% in 2013, dropping to 3.3% by 2016. From a random subset of 2,423 Shih Tzus that had information extracted on disorders diagnosed during 2016, the most prevalent fine-level precision disorders were periodontal disease (n = 229, prevalence 9.5%, 95% CI: 8.4-10.7), anal sac impaction (180, 7.4%, 95% CI: 6.5-8.5) and ear disorders (134, 5.5%, 95% CI: 4.7-6.5). The most prevalent grouped-level precision disorders were cutaneous (n = 402, prevalence: 16.6%, 95% CI: 15.2-18.1), dental (322, 13.3%, 95% CI: 12.0-14.7), and ophthalmological (289, 11.9%, 95% CI: 10.7-13.3). Males were more likely than females to be diagnosed with skin disorders (P = 0.007) and musculoskeletal disorders (P = 0.010) while females were more likely than males to be diagnosed with hernias (P = 0.005). The median age of death was 12.7 years (IQR 8.7-14.3, range 2.0-19.9) and did not differ statistically between males and females. The most common grouped causes of death were enteropathy (7.9%, 95% CI: 3.9-15.4), heart disease (7.9%, 95% CI: 3.9-15.4) and poor quality of life (7.9%, 95% CI: 3.9-15.4). CONCLUSIONS: Periodontal disease, anal sac impaction and ear disorders were identified as common health issues. Shih Tzus had higher prevalence of anal sac impaction, umbilical hernias and eye problems than reported previously in dogs overall, suggesting potential predispositions. Shih Tzus appear to be relatively long-lived compared to previous reports of lifespan in dogs overall. The results can inform veterinarians and owners on priority disorders for monitoring to protect welfare. Oral hygiene was highlighted as a healthcare priority.

The Shih Tzu is a popular small breed of dog in the UK. However, there is little information on common health conditions affecting this breed. This study aimed to describe the demography, common disorders, and causes of death of Shih Tzus in the UK in 2016 using the VetCompass™ Programme, which holds a database of anonymized clinical records of dogs attending primary-care veterinary practices in the UK.The study included 11,082 Shih Tzus (3.3%) from 336,865 dogs under veterinary care in the UK in VetCompass™ in 2016. The popularity of the Shih Tzu increased slightly from 2005 to 2013 but showed signs of decline towards 2016. The average age of Shih Tzus in the study was 4.1 years and the average adult bodyweight was 7.9 kg. The most common disorders affecting Shih Tzus in the study were periodontal disease (inflammation of the gums and tissue around the teeth, affecting 9.5% of Shih Tzus), anal sac impaction (7.4%) and ear disorders (5.5%). Male Shih Tzus were more likely than females to have skin and musculoskeletal disorders (conditions affecting bones, muscles and joints), while female Shih Tzus were more likely be diagnosed with hernias (when internal tissues push out through weakened muscle tissues). Shih Tzus had higher prevalence of anal sac impaction, umbilical hernias and eye problems than previously reported in dogs overall, suggesting potential predispositions. The average age at death of Shih Tzus was 12.7 years of age and the most common causes of death were enteropathy (gastrointestinal diseases causing signs such as diarrhoea and vomiting, 7.9%), heart disease (7.9%) and poor quality of life (7.9%).This study demonstrated the value of analysis of veterinary clinical records to increase our understanding of common health problems affecting dogs in the UK. The results can help both current and prospective Shih Tzu owners, and veterinarians, in prioritising preventative healthcare for Shih Tzus. For example, the most common disorder in Shih Tzus was periodontal disease, suggesting that increased preventative dental checkups and toothbrushing could improve welfare, especially if implemented from an early age.

Is it now time to iron out the wrinkles? Health of Shar Pei dogs under primary veterinary care in the UK.

BACKGROUND: The Shar Pei is a common dog breed with a distinctive appearance caused by hyaluronosis that has been linked with several health conditions. Anonymised primary-care veterinary clinical records were explored to extract data on the demography, common disorders and mortality of Shar Pei in the UK in 2013. RESULTS: The study population of 455,557 dogs included 1913 (0.42%) Shar Pei. The mean adult bodyweight was 22.26 kg. The most prevalent fine-level precision disorders were entropion (prevalence 17.88%, 95% CI: 16.16-19.59), otitis externa (16.36%, 95% CI: 14.70-18.02), ear disorders (6.69%, 95% CI: 5.57-7.81), aggression (5.23%, 95% CI: 4.23-6.22), and pyoderma (4.29%, 95% CI: 3.38-5.19). The most prevalent disorder groups were ophthalmologic (prevalence = 22.27%, 95% CI: 20.40-24.13), dermatological (21.01%, 95% CI: 19.19-22.84), aural (18.66%, 95% CI: 16.92-20.41), traumatic injury (7.53%, 95% CI: 6.35-8.71) and behavioural (7.21%, 95% CI: 6.05-8.37). The median longevity of 190 Shar Pei that died during the study period was 7.28 years (IQR 5.04-10.05, range 0.04-15.04). Of 184 deaths with a recorded method of death, 157 (85.33%) deaths involved euthanasia and 27 (14.67%) deaths were unassisted. Among 136 (71.58%) deaths with a recorded biomedical cause of death, the most common causes of death at group level precision were neoplasia (15.44%, 95% CI: 9.37-21.51), renal disorders (13.24%, 95% CI: 7.54-18.93), and behavioural disorders (11.03%, 95% CI: 5.76-16.29). CONCLUSIONS: Almost one fifth of Shar Pei receive veterinary care each year for entropion, a condition linked strongly with the extreme conformation of thickened and folded skin and bristly hair that characterises the Shar Pei breed. Several other common disorders are also linked to hyaluronosis. Current UK legislation can help support efforts to avoid breeding or acquiring animals with extreme conformations and to promote adequate veterinary care for already-owned animals with extreme conformations.

The Shar Pei dog breed is instantly recognisable by their copious loose folded skin and bristly coat, with Shar Pei translating from Chinese as 'sand paper skin'. Although originally a fighting, hunting and guarding dog in China, the Shar Pei breed was re-invented in the US as a companion animal in the late 1970s where a more wrinkled and heavy-set American 'meat mouth' variety replaced the traditional 'bone mouth' variety originally popular in China. However, the underlying disease of hyaluronosis that causes the characteristic extreme appearance of the Shar Pei has also been linked with several other health problems in the breed such as in-turned eyelids (entropion) and ear disease. Using anonymised veterinary clinical records collected within the VetCompass Programme at the Royal Veterinary College (RVC), Shar Pei made up 0.4% of all dogs in the UK in 2013 and had an average adult bodyweight of 22 kg. The most common specific disorders diagnosed in Shar Pei were in-turned eyelids (17.88%), ear infection (16.36%), ear problems (6.69%), aggression (5.23%), and skin infection (4.29%). Among the 30 most common specific disorders, females were more likely to show in-turned eyelids and conjunctivitis, while males were more likely to show aggression and infected paws. Once the disorders were grouped, the most common disorder groups were eye disorders (22.27%), skin (21.01%), ear (18.66%), traumatic injury (7.53%), and behavioural (7.21%). The average lifespan of Shar Pei was 7.28 years. The most common causes of death were cancer (15.44%,), kidney disorders (13.24%), and behavioural disorders (11.03%). This study highlights that almost one fifth of the breed receive veterinary care each year for in-turned eyelids that can lead to extreme pain and are linked to the thickened and folded skin that humans find so appealing in this breed. Current UK legislation can help support concerted efforts from all animal welfare stakeholders to avoid breeding or acquiring animals with these and other extreme conformations and to promote adequate veterinary care for already-owned animals with extreme conformations.

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.

Dog breeds and conformations in the UK in 2019: VetCompass canine demography and some consequent welfare implications.

INTRODUCTION: Growing concerns over health and welfare impacts from extreme phenotypes in dogs have created an urgent need for reliable demographic information on the national breed structures of dogs. METHODS: This study included all dogs under primary veterinary care in the UK during 2019 at practices participating in VetCompass. Demographic data on these dogs were analysed to report on the frequency of common breeds and also to report on conformation, bodyweight, sex and neuter associations with these breeds. RESULTS: The study included 2,237,105 dogs under UK veterinary care in 2019. Overall, 69.4% (n = 1,551,462) were classified as purebred, 6.7% (149,308) as designer-crossbred and 24.0% (536,335) as nondesigner-crossbred. Across 800 unique breed names, the most frequent breeds at any age were nondesigner-crossbred (n = 536,335, 24.0%), Labrador Retriever (154,222, 6.9%) and Jack Russell Terrier (101,294, 4.5%). Among 229,624 (10.3%) dogs aged under one year, the most frequent breeds were nondesigner-crossbred (n = 45,995, 20.0%), French Bulldog (16,036, 7.0%) and Cockapoo (14,321, 6.2%). Overall, based on breed characteristics, 17.6% (395,739) were classified as brachycephalic, 43.1% (969,403) as mesaticephalic and 8.3% (186,320) as dolichocephalic. Of 1,551,336 dogs that were classifiable based on breed, 52.6% (815,673) were chondrodystrophic. Of 1,462,925 dogs that were classifiable, there were 54.6% (n = 798,426) short haired, 32.6% (476,883) medium haired and 12.8% (186,934) long haired. Of 1,547,653 dogs that were classifiable for ear carriage, 24.5% (n = 379,581) were erect, 28.1% (434,273) were semi-erect, 19.7% (305,475) were v-shaped drop and 27.7% (428,324) were pendulous. Overall, there was a 1.09:1.00 ratio of male (n = 1,163,512; 52.2%) to female dogs (n = 1,067,552; 47.8%). CONCLUSIONS: Health and welfare issues linked to popular breeds with extreme phenotypes suggest that there is much work to do to help owners to make more welfare-friendly decisions when choosing which type of dog to own.

Dog breeds and conformations predisposed to osteosarcoma in the UK: a VetCompass study.

BACKGROUND: Osteosarcoma is a malignant bone neoplasia that has high welfare consequences for affected dogs. Awareness of breed and canine conformational risk factors for osteosarcoma can assist with earlier diagnosis and improved clinical management. Study of osteosarcoma in dogs also offers translational value for humans. Anonymised clinical data within VetCompass on dogs under primary veterinary care in the UK were searched for osteosarcoma cases. Descriptive statistics reported overall and breed-specific prevalence. Risk factor analysis used multivariable logistic regression modelling. RESULTS: From 905,552 study dogs, 331 osteosarcoma cases were confirmed yielding a one-year period prevalence of 0.037% (95% CI: 0.033-0.041). Breeds with the highest annual prevalence were the Scottish Deerhound (3.28%, 95% CI 0.90-8.18), Leonberger (1.48%, 95% CI 0.41- 3.75), Great Dane (0.87%, 95% CI 0.43- 1.55) and Rottweiler (0.84%, 95% CI 0.64-1.07). The median age at diagnosis was 9.64 years (IQR: 7.97-11.41). Following multivariable modelling, 11 breeds showed increased odds of osteosarcoma compared with crossbred dogs. Breeds with the highest odds included Scottish Deerhound (OR 118.40, 95% CI 41.12-340.95), Leonberger (OR 55.79, 95% CI 19.68-158.15), Great Dane (OR 34.24, 95% CI 17.81-65.83) and Rottweiler (OR 26.67, 95% CI 18.57-38.29). Compared with breeds with mesocephalic skull conformation, breeds with dolichocephalic skull conformation (OR 2.72, 95% CI 2.06-3.58) had increased odds while breeds with brachycephalic skull conformation showed reduced odds (OR 0.50, 95% CI 0.32-0.80). Chondrodystrophic breeds had 0.10 times the odds (95% CI 0.06-0.15) compared with non-chondrodystrophic breeds. Increasing adult bodyweight was associated with increasing odds of osteosarcoma. CONCLUSIONS: The current study cements the concept that breed, bodyweight and longer leg or longer skull length are all strong risk factors for osteosarcoma in dogs. With this awareness, veterinarians can update their clinical suspicion and judgement, breeders can select towards lower-risk animals, and researchers can robustly define more useful study populations for fundamental and translational bioscience.

Osteosarcoma describes a serious bone tumour. Affected dogs often show a bony or soft tissue swelling with severe pain. Canine and human osteosarcoma show similar patient characteristics, clinical course and tumour biology that make studies on canine osteosarcoma highly valuable to inform on the human disease. This study aimed to interrogate anonymised veterinary clinical data from the VetCompass Programme to explore whether demographic information on dogs such as breed, bodyweight and body shape could be useful to predict osteosarcoma. VetCompass shares anonymised veterinary clinical records for welfare-focused research. This study explored the records of 905,552 dogs under veterinary care in 2016 to identify all cases of osteosarcoma. Advanced statistical methods were used to evaluate links between demographic factors and the risk of osteosarcoma. From the overall study population of 905,552 dogs, there were 331 osteosarcoma cases identified to show a one-year period prevalence of 0.037%. The breeds with the highest frequency of osteosarcoma were the Scottish Deerhound (3.28%), Leonberger (1.48), Great Dane (0.87%), Rottweiler (0.84%) and Greyhound (0.62%). Eleven breeds showed increased risk of osteosarcoma compared with crossbred dogs. Breeds with the highest risk included Scottish Deerhound (× 118.40 times risk), Leonberger (× 55.79), Great Dane (× 34.24) and Rottweiler (× 26.67). Aging was progressively and strongly associated with increasing risk of osteosarcoma. Dogs weighing heavier that the average for their breed had 1.65 times the risk than animals weighing below the breed average. Insured dogs had 1.71 times the risk of being diagnosed with osteosarcoma compared with uninsured dogs which may indicate higher levels of healthcare given to insured dogs compared to uninsured dogs. Chondrodystrophic (short-legged) breeds had 0.10 times the risk of osteosarcoma compared with non-chondrodystrophic breeds. Compared with breeds with mesocephalic (average length) skull conformation, breeds with dolichocephalic (long) skull conformation (× 2.72) had increased odds of osteosarcoma while breeds with brachycephalic (short) skull conformation showed reduced risk (× 0.50). This study cements the concept that breed, bodyweight and longer leg or longer skull length all predispose to osteosarcoma in dogs. With this awareness, veterinarians can update their clinical suspicion and judgement, breeders can select towards lower-risk animals, and researchers can define more useful study populations for better research.

Demography and disorders of English Cocker Spaniels under primary veterinary care in the UK.

BACKGROUND: The English Cocker Spaniel (ECS) is a common family dog in the UK. This study aimed to describe demography, morbidity, and mortality in ECS under primary veterinary care in the UK during 2016 using data from the VetCompass™ Programme. This study hypothesised that the prevalence of aggression is higher in male than female ECS, and higher in solid-coloured than bi-coloured ECS. RESULTS: English Cocker Spaniels comprised 10,313/336,865 (3.06%) of dogs under primary veterinary care during 2016. The median age was 4.57 years (inter-quartile range (IQR) 2.25-8.01) and the median adult bodyweight was 15.05 kg (IQR 13.12-17.35). The annual proportional birth rate was relatively stable between 2.97-3.51% from 2005-2016. The most common specific diagnoses were periodontal disease (n = 486, prevalence 20.97%, 95% confidence interval (CI): 19.31-22.62), otitis externa (n = 234, 10.09%, 95% CI: 8.87-11.32), obesity (n = 229, 9.88%, 95% CI: 8.66-11.09), anal sac impaction (n = 187, 8.07%, 95% CI: 6.96-9.18), diarrhoea (n = 113, 4.87%, 95% CI: 4.00-5.75), and aggression (n = 93, 4.01%, 95% CI: 3.21-4.81). The prevalence of aggression was higher in males (4.95%) than in females (2.87%) (P = 0.015) and in solid-coloured (7.00%) than in bi-coloured dogs (3.66%) (P = 0.010). The median age at death was 11.44 years (IQR 9.46-13.47) and the most common grouped causes of death were neoplasia (n = 10, 9.26%, 95% CI: 3.79-14.73), mass-associated disorders (n = 9, 8.33%, 95% CI: 4.45-15.08), and collapse (n = 8, 7.41%, 95% CI: 3.80-13.94). CONCLUSIONS: Periodontal disease, otitis externa, and obesity are identified as the most common health issues for ECS, and neoplasia and mass-associated disorders as the most common reasons for death. The prevalence of aggression was higher in males and solid-coloured dogs. The results can aid veterinarians in giving evidence-based health and breed choice information to dog owners and highlights the importance of thorough oral examination and body condition score evaluation during routine veterinary examination of ECS.

The English Cocker Spaniel (ECS) is a popular family dog in the UK, but there is limited information regarding common disorders affecting the breed. The goal of this study was to describe demography (age, sex, neuter, and bodyweight), disease occurrence, lifespan, and reasons for death in ECS by using data from the VetCompass™ Programme. The VetCompass™ Programme collects information from anonymised clinical records of dogs attending first-opinion veterinary practices in the UK. This study hypothesised that aggression is more common in males than in females, and in solid-coloured than in bi-coloured ECS dogs.English Cocker Spaniels comprised 10,313/336,865 (3.06%) of dogs under primary veterinary care during 2016. Breed popularity did not vary much from 2005 to 2016, comprising around 3% of all dogs born each year. The average age of dogs in 2016 was 4.57 years and the average adult bodyweight was 15.05 kg. The most common disorders were periodontal disease (infection of the tissues that hold the teeth in place, affecting 20.97% of the dogs), inflammation of the external ear canal (10.09%), obesity (9.88%), anal sac impaction (8.07%), diarrhoea (4.87%), and aggression (4.01%). Aggression was more common in males (4.95%) than in females (2.87%) and in solid-coloured (7.00%) than in bi-coloured (3.66%) dogs. The frequency of aggression also varied across the four most common solid colours (black, liver, golden, red), with golden-coloured dogs showing the most aggression (12.08%). The average lifespan was 11.44 years and the most common cause of death was tumours.This study shows that first-opinion clinical records can help us to understand and enhance breed health. The results can guide veterinarians in giving breed-adapted information to owners of ECS and help breeders to optimise breeding decisions. Further, this information can be used by future ECS owners to make more informed decisions when acquiring a dog if avoidance of aggression is a key priority. Periodontal disease was the most common condition affecting the breed, which highlights the importance of regular veterinary dental checks and as well as tooth brushing in ECS.

Demography, common disorders and mortality of Boxer dogs under primary veterinary care in the UK.

BACKGROUND: The Boxer is a popular dog breed with a distinctive appearance. However, the breed has been linked with several health conditions, some of which have been associated with its moderately brachycephalic conformation and its white colouration. Anonymised primary-care veterinary clinical records were explored to extract data on the demography, common disorders and mortality of Boxers in the UK in 2016. RESULTS: The study population of 336,865 dogs included 3,219 (0.96%) Boxers, of which 10.71% were recorded as white. The mean adult bodyweight was 30.43 kg (SD 5.73 kg). Annual disorder counts did not differ statistically between the sexes or between white and non-white Boxers. The most prevalent fine-level precision disorders were otitis externa (n = 230, 7.15%), epulis (188, 5.84%), corneal ulceration (161, 5.00%) and periodontal disease (149, 4.63%). Of the 34 most common fine-level disorders, none differed in prevalence between white and non-white dogs. The most prevalent disorder groups were skin disorder (n = 571, 17.74%), neoplasia (457, 14.20%) and ear disorder (335, 10.41%). White Boxers had higher prevalence than non-white Boxers for two disorder groups: dental disorder and brain disorder. The median longevity of 346 Boxers that died during the study was 10.46 years (IQR 9.00-11.98, range 2.76-18.00). Median longevity did not differ statistically between the sexes or between white and non-white Boxers. The most common grouped causes of death were death - unrecorded cause (n = 73, 21.10%), neoplasia (43, 12.43%) and brain disorder (33, 9.54%). CONCLUSIONS: There was minimal evidence of substantial health differences between white and non-white Boxers. Among the four most common disorders recorded in Boxers, two were typically common across all types of dogs (otitis externa and periodontal disease) while two suggested strong predispositions for the Boxer breed (epulis and corneal ulceration), showing the value of eliciting breed-specific disorder patterns for insights for potential health reforms. The overall longevity of Boxer dogs was consistent with other breeds of similar body size.

The Boxer is a medium-large sized, active dog with a short coat and a moderately flat-faced (brachycephalic) skull shape. Despite many decades of popularity in the UK, there is limited published evidence on the overall health profile of Boxers. White-coloured Boxers are thought to be at higher risk of deafness from birth and as a result, white Boxers have traditionally often been culled at birth by breeders.Using anonymised veterinary clinical records collected within the VetCompass Programme at the Royal Veterinary College (RVC), Boxers made up around 1% of all dogs in the UK in 2016, with an average adult bodyweight around 30 kg. The most common colours were brindle (22.82%), dark red (22.62%) and dark red multi-colour (20.92%), with 10.71% white Boxers. Across the 3,219 Boxers in the study, 73.97% had at least one disorder recorded during 2016. The average number of disorders per year did not differ statistically between female and male Boxers, or between white and non-white Boxers. The most common specific disorders in Boxers were ear infection (7.15%), gum mass (5.84%), eye ulcer (5.00%) and dental disease (4.63%). White and non-white dogs did not differ in their risk for any of the 34 most common specific disorders. Only two dogs in the study were recorded with deafness; one white and one non-white. The average lifespan of Boxers overall was 10.46 years. Lifespan did not differ statistically between female and male Boxers, or between white and non-white Boxers.This study identifies ongoing popularity for the Boxer in the UK, with around 10% of these Boxers being white. There was minimal evidence of health differences between male and female Boxers, or between white and non-white Boxers. Among the four most common disorders recorded in Boxers, two are typically common across all types of dogs (ear and dental disease) while two showed strong predisposition in the Boxer breed (gum mass and eye ulcer), suggesting the value of understanding breed-specific health patterns to prioritise health plans for each breed. The overall longevity of Boxer dogs was typical of other breeds of this body size.

Assessment of glucocorticoid and antibiotic exposure as risk factors for diabetes mellitus in selected dog breeds attending UK primary-care clinics.

BACKGROUND: Diabetes mellitus (DM) is an important endocrine disorder in dogs. This study explored prior exposure to glucocorticoids or antibiotic treatment as risk factors for developing DM in dogs attending primary-care VetCompass clinics in the UK. METHODS: A breed frequency matched case-control study nested in a cohort of dogs (n = 480,469) aged 3 years or over was used to explore associations between glucocorticoid and antibiotic exposure and the odds of developing DM. RESULTS: A total of 565 cases and 2179 controls were included. Dogs with DM had over four times the odds of exposure to glucocorticoids within 6 weeks prior to diagnosis (odds ratio [OR] 4.07, 95% confidence interval [CI] 2.41-6.89, p < 0.001) compared to controls within 6 weeks prior to a randomly selected quasi-date of diagnosis. Dogs that had only one unique documented antibiotic course had a decreased odds of developing DM (OR 0.65, 95% CI 0.46-0.91, p = 0.012) compared to dogs that had no documented courses of antibiotics. LIMITATIONS: This study only included selected breeds, so the results may not be generalisable to all dog breeds. CONCLUSIONS: Exposure to glucocorticoids is associated with a substantial increase in the risk of developing DM for the dog breeds included in this analysis.

Periodontal disease in cats under primary veterinary care in the UK: frequency and risk factors.

OBJECTIVES: Periodontal disease is a multifactorial inflammatory disease that can have major welfare implications in cats. This study aimed to report the frequency and demographic risk factors of periodontal disease and to explore associations with common comorbid disorders in cats in the UK. METHODS: The study included a random sample of 18,249 cats obtained from 1,255,130 cats under primary care during 2019 from clinics participating in the VetCompass programme. All disorders recorded during 2019 were extracted and reported. Risk factor and comorbid disorder analysis used multivariable logistic regression modelling. RESULTS: Periodontal disease had a 1-year period prevalence of 15.2% (95% confidence interval [CI] 14.72-15.76). Breeds with the highest prevalence included Siamese (18.7%, 95% CI 12.24-26.72) and Maine Coon (16.7%, 95% CI 11.37-23.18). The median age of cats with periodontal disease (9.47 years, interquartile range [IQR] 5.96-12.97) was higher than for cats without periodontal disease (4.94 years, IQR 1.95-9.51; P <0.001). Increasing adult body weight, increasing age and sex-neuter status were significantly associated with rising odds of periodontal disease. Cats with periodontal disease had a higher median count of comorbid disorders per individual cat (3, IQR 2-4, range 1-14) than cats without periodontal disease (1, IQR 0-2, range 0-15; P <0.001). Cats with periodontal disease had 1.79 times the odds (95% CI 1.62-1.99, P <0.001) of diagnosis with at least one comorbid disorder disease than cats without periodontal disease. CONCLUSIONS AND RELEVANCE: Periodontal disease is the most common specific diagnosis in cats and is confirmed as a leading health issue in cats. Ageing is identified as the strongest predictor of periodontal disease risk in cats, suggesting the potential for increasing health gains from emphasis on dental care and health in cats as they age. The study offers evidence on a close link between periodontal disease and reduced overall health in cats.

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.

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.

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.

Occurrence and clinical management of urethral obstruction in male cats under primary veterinary care in the United Kingdom in 2016.

BACKGROUND: Urethral obstruction (UO) has a negative effect on welfare of cats. OBJECTIVES: This study aimed to determine incidence, case management, and outcomes of UO in cats in primary-care practice in the United Kingdom. ANIMALS: All male cats under veterinary care within the VetCompass database in 2016. METHODS: A retrospective cohort study was performed. The electronic records of all male cats with a clinical note during the study period were searched for UO cases and were manually reviewed for inclusion. Additional demographic and clinical information were extracted on cases. RESULTS: From the study cohort of 237 825 male cats, there were 1293 incident cases. The estimated UO incidence risk during 2016 was 0.54 (95% CI: 0.51-0.57). Demographic and clinical data were available for 1108 cases. Antibiotics were administered to 641/1108 (57.9%) cases. Overall repeat catheterization rate was 253/854 (29.6%). Repeat catheterization at 48 hours was less frequent in patients with indwelling catheters (10.1%) vs those that had a catheter placed and then immediately removed (14.8%; P = .04). Death during a UO episode was 329/1108 (29.6%), and 285/329 (88.0%) deaths involved euthanasia. CONCLUSIONS AND CLINICAL IMPORTANCE: Antibiotics were commonly prescribed in cats for treatment of UO despite minimal evidence in the clinical records of bacterial cystitis. Repeat catheterization was common and case fatality rate during a UO episode was high. Repeat catheterization within 48 hours of elective removal of a urethral catheter was less common in cats that had previously had indwelling catheters. The majority of cats requiring repeat catheterization survived until the end of the study.

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.

Associations between respiratory signs, thoracic CT findings and results of tracheobronchoscopy and bronchoalveolar lavage in dogs.

BACKGROUND: Several diagnostic techniques are used in dogs with signs of respiratory disease. The aims of the present study are to estimate the relative sensitivities and associations between the results of diagnostic tests in dogs with respiratory conditions. METHOD: A retrospective cross-sectional study of dogs referred for investigation of respiratory signs. Associations between clinical signs, thoracic CT findings, tracheobronchoscopic findings, cytology results and bacterial culture results were tested using binary logistic regression. RESULTS: One hundred and thirty-three dogs were included. Abnormalities were detected by cytology, tracheobronchoscopy, CT and bacterial culture in 91%, 88%, 80% and 25% cases, respectively. There were associations between cough and bronchial lesions on thoracic CT (odds ratio [OR] 2.6, 95% confidence interval [CI] 1.1-6.4, p = 0.037), and between cough and neutrophilic inflammation on cytology (OR 4.5, 95% CI 1.3-15.8, p = 0.020). Bronchial foreign body at bronchoscopy was associated with pulmonary consolidation on CT (OR 8.0, 95% CI 1.6-41.7, p = 0.013) and with positive bacterial culture (OR 10.9, 95% CI 2.1-57.0, p = 0.005). In dogs with normal thoracic CT, abnormalities were detected by cytology, tracheobronchoscopy and bacterial culture in 89%, 77% and 23% cases, respectively. CONCLUSION: Airway cytology and tracheobronchoscopy provided useful information for diagnosis in many dogs with respiratory signs that had a normal thoracic CT.