Canine genetics and epidemiology最新文献

Background: Individual dog breeds are often reported as predisposed to specific breed-related disorders but reliable epidemiological data on disease prevalence are sparse. The Miniature Schnauzer in the UK is a popular small breed dog that is often considered as relatively healthy and long-lived, but is this really true? This study aimed to use data from the VetCompass™ Programme at the Royal Veterinary College to characterise the demography, mortality and common disorders of the general population of Miniature Schnauzers under veterinary care in the UK.

Results: The study population of 455,557 dogs from 304 clinics in the VetCompass™ database under veterinary care during 2013 included 3857 Miniature Schnauzers (0.85%). For dogs with data available, 1771 (56.9%) were neutered and 1893 (49.2%) were females. Mean adult bodyweight overall was 9.9 kg (SD 2.2 kg) and median longevity was 11.6 years (IQR 9.3-13.1, range 0.5-17.0). The most prevalent fine-level precision disorders recorded were periodontal disease (n = 343, prevalence 17.4, 95% CI: 15.7-19.1), obesity/overweight (164, 8.3, 95% CI: 7.1-9.6), anal sac impaction (114, 5.8, 95% CI: 4.8-6.9), vomiting (100, 5.1, 95% CI% 4.1-6.1) and otitis externa (99, 5.0, 95% CI% 4.1-6.1). The most prevalent grouped-level precision disorders were dental (n = 378, prevalence: 19.2, 95% CI: 17.5-21.0), enteropathy (270, 13.7, 95% CI: 12.2-15.3), cutaneous (250, 12.7, 95% CI: 11.2-14.2) and aural (197, 10.0, 95% CI: 8.7-11.4).

Conclusions: This study provides generalisable evidence on the demography, longevity and most prevalent disorders in the Miniature Schnauzer breed in the UK. Awareness of common diseases and breed predispositions can support evidence-based policies to improve breed health, guide veterinary surgeons when producing differential diagnosis lists, and assist owners when purchasing or caring for their pets.

Background: Selective breeding in populations with a limited effective population size may result in a loss of genetic diversity, which can cause an increased concentration of specific disease liability genes. The Dutch Shepherd Dog (DSD) in the Netherlands is an example of such a breed with a small effective population.

Objective: To evaluate the measurement of genetic diversity and multiplex DNA panel screening for implementation in a breeding strategy for the Dutch Shepherd Dog (DSD) and to investigate the clinical relevance of potentially identified mutations in the multiplex DNA panel screening.

Results: Genome-wide SNP testing showed genetic isolation and reduced genetic diversity within coat variety subgroups of the DSD. Panel screening identified a Von Willebrand's Disease type I mutation. Although decreased Von Willebrand's Factor proteins were significantly lower in DSDs carrying the VWD-I allele compared to the wildtype, clinical follow-up did not show a significant association between the clinical phenotype and VWD-I genotype.

Conclusions: Genetic relationship measurement within a breed population may be a useful tool to enable breeding strategies to conserve genetic diversity. Results from a disease panel screening need to be evaluated for clinical relevance before breed selection restrictions can be considered.

Background: Intervertebral disc herniation (IVDH) involves displacement of the intervertebral disc secondary to disc degeneration and is extremely common in dachshunds. Clinical signs include pain with or without paresis or paralysis. Mortality rate is high and some cases are left with permanent disability even after treatment. Aims of this study were twofold: Firstly, to investigate whether neutering, i.e. gonadectomy, is associated with increased risk of IVDH in dachshunds, and secondly to investigate whether age of neutering alters risk of IVDH in this breed.Information was obtained for 1964 dachshunds from the owner survey, "Dachslife 2015". For dachshunds that were ≥ 3 years and < 10 years old at the time of the survey (1073 individuals) incidence of IVDH was compared between early-neutered (< 12 months), late-neutered (> 12 months) and entire animals of each gender.

Results: Neutered females were at significantly higher risk of IVDH than entire females (risk ratio 1.81, 95% CI 1.28-2.54). For males, incidence of IVDH in neutered as compared with entire dachshunds was increased but this difference was not quite statistically significant (risk ratio 1.38, 95% CI 0.96-1.99).For both genders, this study demonstrated significantly increased risk of IVDH in early-neutered dachshunds (before 12 months old) as compared with those neutered late (after 12 months old). For early neutered males, risk ratio was 1.54 (95% CI 1.07-2.22). For early-neutered females, risk ratio was 2.12 (95% CI 1.44-3.11).

Conclusion: Results from this retrospective study suggest that gonadectomy, especially if performed before 12 months old, increases risk of IVDH in this breed. Decisions regarding neutering should be made on an individual basis, taking a range of pros and cons into account. Considering the high prevalence, morbidity and mortality of IVDH in dachshunds, increased IVDH risk associated with neutering is a key factor to consider in deciding whether and when to neuter.

Background: Labrador retrievers are reportedly predisposed to many disorders but accurate prevalence information relating to the general population are lacking. This study aimed to describe demography, mortality and commonly recorded diseases in Labrador retrievers under UK veterinary care.

Methods: The VetCompass™ programme collects electronic patient record data on dogs attending UK primary-care veterinary practices. Demographic analysis covered all33,320 Labrador retrievers in the VetCompass™ database under veterinary care during 2013 while disorder and mortality data were extracted from a random sample of 2074 (6.2%) of these dogs.

Results: Of the Labrador retrievers with information available, 15,427 (46.4%) were female and 15,252 (53.6%) were male. Females were more likely to be neutered than males (59.7% versus 54.8%, P <  0.001). The overall mean adult bodyweight was 33.0 kg (SD 6.1). Adult males were heavier (35.2 kg, SD 5.9 kg) than adult females (30.4 kg, SD 5.2 kg) (P <  0.001). The median longevity of Labrador retrievers overall was 12.0 years (IQR 9.9-13.8, range 0.0-16.0). The most common recorded colours were black (44.6%), yellow (27.8%) and liver/chocolate (reported from hereon as chocolate) (23.8%). The median longevity of non-chocolate coloured dogs (n = 139, 12.1 years, IQR 10.2-13.9, range 0.0-16.0) was longer than for chocolate coloured animals (n = 34, 10.7 years, IQR 9.0-12.4, range 3.8-15.5) (P = 0.028).Of a random sample of 2074 (6.2%) Labrador retrievers under care in 2013 that had full disorder data extracted, 1277 (61.6%) had at least one disorder recorded. The total number of dogs who died at any date during the study was 176. The most prevalent disorders recorded were otitis externa (n = 215, prevalence 10.4%, 95% CI: 9.1-11.8), overweight/obesity (183, 8.8%, 95% CI: 7.6-10.1) and degenerative joint disease (115, 5.5%, 95% CI: 4.6-6.6). Overweight/obesity was not statistically significantly associated with neutering in females (8.3% of entire versus 12.5% of neutered, P = 0.065) but was associated with neutering in males (4.1% of entire versus 11.4% of neutered, P < 0.001). The prevalence of otitis externa in black dogs was 12.8%, in yellow dogs it was 17.0% but, in chocolate dogs, it rose to 23.4% (P < 0.001). Similarly, the prevalence of pyo-traumatic dermatitis in black dogs was 1.1%, in yellow dogs it was 1.6% but in chocolate dogs it rose to 4.0% (P = 0.011).

Conclusions: The current study assists prioritisation of health issues within Labrador retrievers. The most common disorders were overweight/obesity, otitis externa and degenerative joint disease. Males were significantly heavier females. These results can alert prospective owners to potential health issues and inform breed-specific wellness checks.

Background: The domestic dog is one of the most diverse mammalian species, exhibiting wide variations in morphology, behaviour and morbidity across breeds. Therefore, it is not unexpected that breeds should also exhibit variation in mortality and longevity. While shorter longevity per se may not necessarily be a welfare issue, a generally foreshortened lifespan in a breed that is accompanied by a high prevalence of a particular cause of death may reveal potentially serious welfare concerns and highlight scope to improve breed welfare. Survey data gathered directly from owners offer useful insights into canine longevity and mortality that can support the overall evidence base for welfare reforms within breeds.

Results: Mortality data on 5663 deceased dogs registered with the UK Kennel Club were collected from an owner-based survey. The most commonly reported causes of death were old age (13.8%), unspecified cancer (8.7%) and heart failure (4.9%); with 5.1% of deaths reported as unknown cause. Overall median age at death was 10.33 years (interquartile range: 7.17-12.83 years). Breeds varied widely in median longevity overall from the West Highland Terrier (12.71 years) to the Dobermann Pinscher (7.67 years). There was also wide variation in the prevalence of some common causes of death among breeds, and in median longevity across the causes of death.

Conclusion: Substantial variation in the median lifespan and the prominent causes of death exists across breeds. This study has identified some breeds with both a low median lifespan and also a high proportional mortality for one or more specific causes of death that should be considered as both potential welfare concerns as well as opportunities for improvement.

Background: Lipomas are masses of mesenchymal origin, comprising of adipocytes, and are often clinically unremarkable but can be alarming to owners. Although lipomas are reportedly common in dogs, no studies have specifically investigated risk factors associated with their occurrence. This study was a large-scale retrospective analysis of electronic patient records of dogs attending practices participating in VetCompass™. Univariable and multivariable logistic regression methods were used to evaluate associations between risk factors and primary-care veterinary diagnosis of lipoma.

Results: From 384,284 dogs under veterinary care during 2013 at 215 primary practice clinics in the UK, there were 2765 lipoma cases identified giving a one-year prevalence of 1.94% (95% CI: 1.87-2.01). Breeds with the highest lipoma prevalence included Weimaraner (7.84%, 95% CI 6.46-9.40), Dobermann Pinscher (6.96%, 95% CI 5.67-8.44), German Pointer (5.23%, 95% CI 3.93-6.80), Springer Spaniel (5.19%, 95% CI 4.76-5.66), and Labrador Retriever (5.15%, 95% CI 4.90-5.41). Dogs with an adult bodyweight equal or higher than their breed/sex mean had 1.96 (95% CI 1.81-2.14, P <  0.001) times the odds of lipoma compared with dogs that weighed below their breed/sex mean. The odds of lipoma increased as adult bodyweight increased. Increased age was strongly associated with increasing odds of lipoma. Compared with dogs aged 3.0 to < 6.0 years, dogs aged 9.0 - < 12.0 years had 17.52 times the odds (95% CI 14.71-20.85, P <  0.001) of lipoma. Neutered males (OR: 1.99, 95% CI 1.69-2.36, P <  0.001) and neutered females (OR: 1.62, 95% CI 1.37-1.91, P <  0.001) had higher odds than entire females. Insured dogs had 1.78 (95% CI 1.53-2.07, P <  0.001) times the odds of lipoma compared with uninsured dogs.

Conclusions: Lipomas appear to be a relatively common diagnosis in primary-care practice. Certain breeds were identified with remarkably high lipoma prevalence, highlighting the risk that owners should be prepared for. Lipoma predisposition of larger bodyweight individuals within breed/sex suggests that being overweight or obese may be a predisposing factor but would need further work to confirm.

Background: Working dog handlers and breeders have very different behavioural requirements in the animals that they employ for managing livestock. The Australian Working Kelpie breed may be used in several working contexts, notably yards, paddocks and a combination of both. The working context influences the skillsets required and gives rise to three corresponding work-types: Yard, Paddock and Utility Kelpies. In particular, dogs used for working stock in the confines of yards and trucks interact with stock more forcefully than those mustering in larger areas (paddocks) where they can herd stock effectively from a greater distance. This article explores owner assessments of dog working quality and assessment of genomic similarity by multidimensional scaling, to ask whether it is sufficient for breeders to aim for a multipurpose breeding objective, or whether breeding only specialist lines maximises user satisfaction for yard and paddock work.

Results: Reported owner perceptions of 298 dogs assessed with the Livestock Herding Dog assessment tool showed that dog handlers across all working types were very happy with their dogs' level of general skills.Compared with both Yard and Utility Kelpies, Paddock Kelpies had significantly lower trait scores for force (pressure applied by the dog to move livestock), willingness to back the stock (run along a sheep's dorsum) and bite (frequency of using the mouth to grab or bite the livestock). Meanwhile, compared with both Paddock and Utility Kelpies, the Yard Kelpies had significantly higher scores for hyperactivity and excitability (both with and without stock) and impulsiveness without stock. As one would predict for all-rounders, Utility Kelpies had intermediate scores for all behaviours and working traits.

Conclusions: Specialist characteristics were displayed by dogs in the Yard Kelpie and Paddock Kelpie groups. In particular, Yard Kelpies demonstrate higher excitability, willingness to back the stock, and a higher tendency to bark and bite the stock. Conversely, Paddock Kelpies rarely display these characteristics. Utility Kelpies, as the name suggests, are intermediate between the other two groups and display the characteristics of both. Genetic analysis suggests that the Yard, Utility and Paddock Kelpies are not distinguishable at a DNA level. In conclusion, at this time there is no suggestion of a breed split in the Australian Working Kelpie generated by selection for work type. A common breeding objective should enable dogs to be produced that fulfil all potential working requirements. This reinforces the importance of breeder skill in recognising the phenotypic potential of pups in order to place them in appropriate working contexts.

Background: Despite its Gallic name, the French Bulldog is a breed of both British and French origin that was first recognised by The Kennel Club in 1906. The French Bulldog has demonstrated recent rapid rises in Kennel Club registrations and is now (2017) the second most commonly registered pedigree breed in the UK. However, the breed has been reported to be predisposed to several disorders including ocular, respiratory, neurological and dermatological problems. The VetCompass™ Programme collates de-identified clinical data from primary-care veterinary practices in the UK for epidemiological research. Using VetCompass™ clinical data, this study aimed to characterise the demography and common disorders of the general population of French Bulldogs under veterinary care in the UK.

Results: French Bulldogs comprised 2228 (0.49%) of 445,557 study dogs under veterinary care during 2013. Annual proportional birth rates showed that the proportional ownership of French Bulldog puppies rose steeply from 0.02% of the annual birth cohort attending VetCompass™ practices in 2003 to 1.46% in 2013. The median age of the French Bulldogs overall was 1.3 years (IQR 0.6-2.5, range 0.0-13.0). The most common colours of French Bulldogs were brindle (solid or main) (32.36%) and fawn (solid or main) (29.9%). Of the 2228 French Bulldogs under veterinary care during 2013, 1612 (72.4%) had at least one disorder recorded. The most prevalent fine-level precision disorders recorded were otitis externa (14.0%, 95% CI: 12.6-15.5), diarrhoea (7.5%, 95% CI: 6.4-8.7), conjunctivitis (3.2%, 95% CI: 2.5-4.0), nails overlong (3.1%, 95% CI% 2.4-3.9) and skin fold dermatitis (3.0%, 95% CI% 2.3-3.8). The most prevalent disorder groups were cutaneous (17.9%, 95% CI: 16.3-19.6), enteropathy (16.7%, 95% CI: 15.2-18.3), aural (16.3%, 95% CI: 14.8-17.9), upper respiratory tract (12.7%, 95% CI: 11.3-14.1) and ophthalmological (10.5%, 95% CI: 9.3-11.9).

Conclusions: Ownership of French Bulldogs in the UK is rising steeply. This means that the disorder profiles reported in this study reflect a current young UK population and are likely to shift as this cohort ages. Otitis externa, diarrhoea and conjunctivitis were the most common disorders in French Bulldogs. Identification of health priorities based on VetCompass™ data can support evidence-based reforms to improve health and welfare within the breed.