Thoracic to lumbar vertebral column length and length ratios in miniature dachshunds with and without thoracolumbar intervertebral disc extrusion.

BACKGROUND: The chondrodystrophic body type predisposes miniature dachshunds to thoracolumbar intervertebral disc extrusion (IVDE). However, the relationship between thoracolumbar IVDE and the relative lengths of the thoracic and lumbar vertebral columns has not yet been evaluated. METHODS: This prospective multicentre study included 151 miniature dachshunds with (n = 47) and without (n = 104) thoracolumbar IVDE. All dogs had their thoracic and lumbar vertebral columns measured with a tape measure. Detailed descriptions were provided to facilitate consistent measurement. A thoracic to lumbar vertebral column ratio was calculated. Thoracolumbar IVDE was confirmed by magnetic resonance imaging or computed tomography. RESULTS: The thoracic to lumbar vertebral column length ratio and absolute thoracic vertebral column length were significantly smaller in miniature dachshunds with IVDE than in those without IVDE (p < 0.0001 for both). There were no significant differences in lumbar vertebral column length, age, sex or neuter status between the two groups. LIMITATIONS: The dogs without IVDE did not undergo a neurological examination and the thoracic and lumbar vertebral column measurements were not validated. CONCLUSIONS: The relative lengths of the thoracic and lumbar vertebral column segments could contribute to the development of thoracolumbar IVDE in miniature dachshunds. Further studies are needed to evaluate ideal thoracic to lumbar vertebral column length ratios in miniature dachshunds.

Neuter status as a risk factor for canine intervertebral disc herniation (IVDH) in dachshunds: a retrospective cohort study.

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.

Nationwide genetic testing towards eliminating Lafora disease from Miniature Wirehaired Dachshunds in the United Kingdom.

BACKGROUND: Canine DNA-testing has become an important tool in purebred dog breeding and many breeders use genetic testing results when planning their breeding strategies. In addition, information obtained from testing of hundreds dogs in one breed gives valuable information about the breed-wide genotype frequency of disease associated allele. Lafora disease is a late onset, recessively inherited genetic disease which is diagnosed in Miniature Wirehaired Dachshunds (MWHD). It is one of the most severe forms of canine epilepsy leading to neurodegeneration and, frequently euthanasia within a few years of diagnosis. Canine Lafora disease is caused by a dodecamer repeat expansion mutation in the NHLRC1 gene and a DNA test is available to identify homozygous dogs at risk, carriers and dogs free of the mutation. RESULTS: Blood samples were collected from 733 MWHDs worldwide, mostly of UK origin, for canine Lafora disease testing. Among the tested MWHD population 7.0% were homozygous for the mutation and at risk for Lafora disease. In addition, 234 dogs were heterozygous, indicating a carrier frequency of 31.9% in the tested population. Among the tested MWHDs, the mutant allele frequency was 0.2. In addition, data from the tested dogs over 6 years (2012-2017) indicated that the frequency of the homozygous and carrier dogs has decreased from 10.4% to 2.7% and 41.5% to 25.7%, respectively among MWHDs tested. As a consequence, the frequency of dogs free of the mutation has increased from 48.1% to 71.6%. CONCLUSIONS: This study provides valuable data for the MWHD community and shows that the DNA test is a useful tool for the breeders to prevent occurrence of Lafora disease in MWHDs. DNA testing has, over 6 years, helped to decrease the frequency of carriers and dogs at risk. Additionally, the DNA test can continue to be used to slowly eradicate the disease-causing mutation in the breed. However, this should be done carefully, over time, to avoid further compromising the genetic diversity of the breed. The DNA test also provides a diagnostic tool for veterinarians if they are presented with a dog that shows clinical signs associated with canine Lafora disease.

Moving from information and collaboration to action: report from the 3rd International Dog Health Workshop, Paris in April 2017.

BACKGROUND: Breed-related health problems in dogs have received increased focus over the last decade. Responsibility for causing and/or solving these problems has been variously directed towards dog breeders and kennel clubs, the veterinary profession, welfare scientists, owners, regulators, insurance companies and the media. In reality, all these stakeholders are likely to share some responsibility and optimal progress on resolving these challenges requires all key stakeholders to work together. The International Partnership for Dogs (IPFD), together with an alternating host organization, holds biennial meetings called the International Dog Health Workshops (IDHW). The Société Centrale Canine (French Kennel Club) hosted the 3rd IDHW, in Paris, in April, 2017. These meetings bring together a wide range of stakeholders in dog health, science and welfare to improve international sharing of information and resources, to provide a forum for ongoing collaboration, and to identify specific needs and actions to improve health, well-being and welfare in dogs. RESULTS: The workshop included 140 participants from 23 countries and was structured around six important issues facing those who work to improve dog health. These included individualized breed-specific strategies for health and breeding, extreme conformations, education and communication in relation to antimicrobial resistance, behavior and welfare, genetic testing and population-based evidence. A number of exciting actions were agreed during the meeting. These included setting up working groups to create tools to help breed clubs accelerate the implementation of breed-health strategies, review aspects of extreme conformation and share useful information on behavior. The meeting also heralded the development of an online resource of relevant information describing quality measures for DNA testing. A demand for more and better data and evidence was a recurring message stressed across all themes. CONCLUSIONS: The meeting confirmed the benefits from inclusion of a diverse range of stakeholders who all play relevant and collaborative parts to improve future canine health. Firm actions were set for progress towards improving breed-related welfare. The next international workshop will be in the UK in 2019 and will be organized by the UK Kennel Club.