Lumbosacral transitional vertebra in 14 dog breeds in Norway: Occurrence, risk factors and association with hip dysplasia.

A lumbosacral transitional vertebra (LTV) is a congenital anomaly of the spine and has been suggested to predispose to canine hip dysplasia (CHD). This retrospective, cross-sectional study investigated the prevalence of LTV and CHD among 14 dog breeds in Norway, the possible associations with risk factors, and whether LTV was a risk factor for the development of hip dysplasia. The results were based on evaluation of ventrodorsal radiographs from the CHD screening program from the Norwegian Kennel Club from February 2014 to January 2022. A total of 13,950 dogs were included in the study. For statistical analysis, CHD grades were reclassified from the official Federation Cynologique Internationale (FCI) grades into three grades: CHD free (CHD=A, B), CHD mild (CHD=C), and CHD severe (CHD=D, E). In the study sample, the overall occurrence of LTV was 18.5%, of which 32.9% were type 1, 45.7% type 2% and 21.4% type 3. The occurrence of LTV varied significantly among the included breeds, ranging from 9.5% to 46.2%. There was no association between sex and LTV. The frequencies of CHD grades were A: 43.1%; B: 31.4%; C: 18.4%; D: 6.0%; E: 1.1%. There was a statistically significant association with mild and severe CHD in dogs with LTV type 2 and LTV type 3 (P< 0.001). In the population studied, the prevalence of LTV was different among breeds. This supports initial data on the heredity of LTV and the diverse occurrence of LTV among breeds. Our results indicate that LTV type 2 and type 3 are associated with mild and severe CHD development. Therefore, this study has potentially identified an additional risk factor for the development of hip dysplasia.

Prevalence of canine hip dysplasia in 10 breeds in France, a retrospective study of the 1997-2017 radiographic screening period.

Canine hip dysplasia (HD) is a complex developmental disease of the coxo-femoral joint and is one of the most common orthopedic conditions in dogs. Due to the genetic contribution, most of the programs fighting against HD recommend selective breeding that excludes affected dogs. Using the best-scoring dogs for breeding may reduce the prevalence of HD. In France, the phenotypic screening of coxo-femoral joint conformation remains a strategy for breeders to establish selection decisions. The HD prevalence was evaluated in 10 breeds, based on the assessment of 27,710 dogs, during the 1997-2017 screening period, which was divided into 3 homogeneous cohorts for analysis. The global HD prevalence varied widely among breeds from 5% (Siberian Husky) to 51.9% (Cane Corso). It decreased over time in 6 breeds, among which 4 (Cane Corso, Gordon Setter, Rottweiler and White Swiss Shepherd) showed a significant decrease. A statistically significant increase in HD prevalence was noted for the Siberian Husky. Although the efficacy of phenotype-based breeding programs remains controversial, our results are in accordance with several recent studies showing that long-term selection policies are valuable, as they may help decreasing the HD prevalence in some breeds. The complementary use of more recent tools such as estimated breeding values and genomics would probably help breeders achieve more substantive results.

Heritability of hip dysplasia: Preliminary results for German Shepherd dogs in Brazil.

The heritability of canine hip dysplasia in German Shepherd dogs was estimated using Bayesian methods. Data on hip score and status of 1632 dogs born from 1990 to 2013 were provided by the Brazilian Society of German Shepherd Breeders. Heritability estimates (mean ± standard deviation) were 0.1979 ± 0.058 for hip scores and 0.187 ± 0.055 for hip status. We observed no phenotypic trends and a small rate of genetic trend (0.52%) according to the year of birth, probably because of ineffective phenotypic selection and absence of genetic selection. The heritability estimates in this study can be used to achieve effective selective breeding and genetic gains, which in turn can result in improvements in dog health and welfare.

Heritabilities and genetic trends for elbow score as recorded by the New Zealand Veterinary Association Elbow Dysplasia Scheme (1992-2013) in four breeds of dog.

AIM: To estimate the heritability of the New Zealand Veterinary Association (NZVA) elbow phenotype, obtain estimated breeding values (EBV) for the worst-elbow score and estimate the genetic trends for this trait in four populous breeds of dogs, using the records from the NZVA Canine Elbow Dysplasia Scheme database (1992-2013). METHODS: Overall, 4,070 elbow records from a pedigree of 11,311 dogs were available for animals scored between 1992 and 2013. The worst elbow score between the left and right elbows was identified for each dog and used for EBV analysis. Estimates of heritability and EBV for the elbow score of dogs from German Shepherd dog, Labrador Retriever, Golden Retriever and Rottweiler breeds were obtained using restricted maximum likelihood procedures with a within-breed linear animal model. The model included the fixed effects of sex and birth year, with age at scoring as a covariable, and the random effect of animal. Genetic trends for the worst-elbow score were calculated as the regression coefficient of the EBV, weighted by reliabilities, on year of birth. RESULTS: The estimates of heritability for worst-elbow score were 0.25 (SE 0.06) in German Shepherd dogs, 0.46 (SE 0.06) in Labrador Retrievers, 0.18 (SE 0.07) in Golden Retrievers and 0.29 (SE 0.11) in Rottweilers. The genetic trend for German Shepherd dogs was -0.0082 (SE 0.0015), for Labrador Retrievers was -0.0016 (SE 0.0016), for Golden Retrievers was -0.0033 (SE 0.0010) and for Rottweilers was -0.0070 (SE 0.0023) units per annum, which were different from zero (p<0.01) in all breeds except Labrador Retrievers. CONCLUSIONS AND CLINICAL RELEVANCE: A small but favourable response to selection was achieved by three of the four breeds in the study period; during which selection for elbow traits has been largely voluntary. While the magnitude of genetic change in terms of elbow units per annum may appear small, it must be remembered that elbow scoring grades only range from 0-3. Greater improvement may be possible if compulsory screening was a requirement for pedigree breeding stock, and if greater selection pressure were applied on the basis on an individual's EBV, rather than the worst-elbow score alone. The maintenance of an open registry, with transparency of EBV information made available to all breeders, may enhance selection intensity opportunities and potentially assist with the process and progress of breeding selection.

Phenotypic hip and elbow dysplasia trends in Rottweilers and Labrador retrievers in South Africa (2007-2015): Are we making progress?

Canine hip and elbow dysplasia are major orthopaedic problems prevalent the world over, and South Africa is no exception. Hip and elbow dysplasia phenotypic status is certified by a number of different radiographic schemes in the world. South Africa uses the Fédération Cynologique Internationale system to certify hips, and the International Elbow Working Group scheme to certify elbows. One way of reducing these often crippling conditions is by selective breeding using only dogs with no or marginal dysplastic joints. In South Africa, only seven breeds, including the Rottweiler, have breeding restrictions for hip dysplasia. There are no such restrictions for elbow dysplasia. This study assessed the prevalence of hip and elbow dysplasia over a 9-year-period in the Rottweiler and the Labrador retriever in South Africa as evaluated by official national scrutineers. Records from 1148 Rottweilers and 909 Labrador retrievers were obtained and were graded as normal or dysplastic, and numerical values were also evaluated. Data were compared between the two breeds, males and females as well as over time and were compared with similar data of the Orthopaedic Foundation for Animals in the United States. The prevalence values for hip dysplasia in Rottweilers and Labrador retrievers were 22% and 31%, respectively, whereas for elbow dysplasia the values were 39% and 19%, respectively. In Labrador retrievers, this incidence was much higher than in the American population. Rottweiler hip and elbow dysplasia numerical scores significantly improved over time, whereas in Labrador retrievers, only hip dysplasia showed a minor but significant improvement. This study proved that prescribing minimum breeding requirements, as in the Rottweiler in this study, significantly improved the breeding stock, suggesting that minimum hip and elbow breeding requirements should be initiated for all breeds at risk of these often crippling conditions.

Etiopathogenesis of Canine Hip Dysplasia, Prevalence, and Genetics.

First identified in 1935, canine hip dysplasia is thought to be the most common orthopedic condition diagnosed in the dog. It is most prevalent in large and giant breed dogs, with a complex polygenic mode of inheritance, and relatively low heritability. External factors including caloric intake when growing have a significant effect on phenotypic expression. Initial joint laxity progresses to osteoarthritis due to subluxation and abnormal wearing. Selective breeding programs to attempt to decrease prevalence have shown modest results so far.

Long-term genetic selection reduced prevalence of hip and elbow dysplasia in 60 dog breeds.

Canine hip dysplasia (CHD) and elbow dysplasia (ED) impact the health and welfare of all dogs. The first formally organized assessment scheme to improve canine health centered on reducing the prevalence of these orthopedic disorders. Phenotypic screening of joint conformation remains the currently available strategy for breeders to make selection decisions. The present study evaluated the efficacy of employing phenotypic selection on breed improvement of hips and elbows using the Orthopedic Foundation for Animals complete database spanning the 1970-2015 time period. Sixty breeds having more than 1000 unique hip evaluations and 500 elbow evaluations (1,056,852 and 275,129 hip and elbow records, respectively) were interrogated to derive phenotypic improvement, sex and age at time of assessment effects, correlation between the two joints, heritability estimates, estimated breeding values (EBV), and effectiveness of maternal/paternal selection. The data demonstrated that there has been overall improvement in hip and elbow conformation with a reduction in EBV for disease liability, although the breeds differed in the magnitude of the response to selection. Heritabilities also differed substantially across the breeds as did the correlation of the joints; in the absence of a universal association of these differences with breed size, popularity, or participation in screening, it appears that the breeds themselves vary in genetic control. There was subtle, though again breed specific, impact of sex and older ages on CHD and ED. There was greater paternal impact on a reduction of CHD. In the absence of direct genetic tests for either of these two diseases, phenotypic selection has proven to be effective. Furthermore, the data underscore that selection schemes must be breed specific and that it is likely the genetic profiles will be unique across the breeds for these two conditions. Despite the advances achieved with phenotypic selection, incorporation of EBVs into selection schemes should accelerate advances in hip and elbow improvement.

15 años de cirugía cardiaca infantil miniinvasiva; evolución y tendencias / 15 years of minimally invasive paediatric cardiac surgery; development and trends

INTRODUCCIÓN: Los abordajes miniinvasivos en cirugía cardiaca infantil no son habituales. Pocos grupos presentan programas y experiencia, quedando limitados a cardiopatías simples. Presentamos una casuística recopilada a lo largo de 15 años y más de 200 pacientes. MATERIAL Y MÉTODOS: En el año 2000 comenzamos un programa de acceso submamario, ampliándolo progresivamente a casos complejos y edades menores. En 2009 incorporamos el abordaje axilar, con idénticas pautas. En 2013 iniciamos la cirugía por miniesternotomía inferior, ampliando la cartera de servicios. Entre julio del 2000 y diciembre del 2014 se intervino a 203 pacientes: 102 por vía submamaria, 50 por axilar, 44 por miniesternotomía inferior, 4 por toracotomía lateral-posterior y 3 por miniesternotomía superior. RESULTADOS: Por patologías, la más frecuente fue la comunicación interauricular ostium secundum (128), seguida del seno venoso (20), comunicación interventricular (20), ostium primum (16) y otras (19). Un caso fue reconvertido a esternotomía. No hubo eventos neurológicos. Las medias de edad fueron 7,8/3,7 y 1,8 años, con medias de peso de 28,1/16,1 y 9,4 kg en los accesos submamario, axilar y miniesternotomía, respectivamente. Los resultados estéticos han sido excelentes. CONCLUSIONES: Tras 15 años de experiencia acumulada, la cirugía miniinvasiva es segura y eficaz, con resultados estéticos excelentes. La introducción gradual de diferentes accesos alternativos permite establecer pautas de aprendizaje. La versatilidad de accesos (submamario, axilar, miniesternotomía) facilita la selección de abordajes en función de cardiopatía y edad/peso

INTRODUCTION: The minimally invasive approach is seldom reported in paediatric cardiac surgery. Teams gathering experience are scarce, with programs focused on simple cases. The experience is presented on a series of over 200 cases operated on in the past 15 years. MATERIAL AND METHODS: A sub-mammary approach program was started in 2000, which was gradually extended to include more complex and younger patients. The axillary incision was adopted in 2009, following the same steps. In 2013, the mini-sternotomy incision was introduced, increasing our armamentarium. From July 2000 until December 2014, 203 patients were operated on. The sub-mammary approach was used in 102 cases, axillary in 50 patients, mini-sternotomy in 44, postero-lateral thoracotomy in 4 cases, and upper mini-sternotomy in 3. RESULTS: By diagnosis, ostium secundum atrial septal defect was the most common (128), followed by sinus venosus (20), ventricular septal defect (20), ostium primum (16), and others (19). One patient was converted to sternotomy. No neurological events were detected. The mean age was 7.8/3.7 and 1.8 years, and the mean weight was 28.1/16.1 and 9.4 Kg. in the sub-mammary, axillary and mini-sternotomy approaches, respectively. The aesthetic results were excellent. CONCLUSIONS: Based on our 15 years of experience, minimally invasive surgery is safe and yields excellent cosmetic results. The gradual introduction of alternative approaches (sub-mammary, axillary, mini-sternotomy) allowed us to set-up guidelines and learning curves. The wide range of incisions enables the most appropriate one to be selected depending on age/weight and cardiac condition

El Pennhip modificado y la sinfisiodesis juvenil pubiana como prevención de displasia de cadera canina en las Fuerzas Armadas / Modified Pennhip and juvenile pubic symphysiodesis as canine hip dysplasia prevention in the Armed Forces

INTRODUCCIÓN: La displasia de cadera canina es la principal causa física de exclusión de los perros de los programas de adiestramiento en las Fuerzas Armadas y los Cuerpos y Fuerzas de Seguridad del Estado, es por ello importante realizar una criba temprana de esta patología. OBJETIVO: Determinar la eficacia del procedimiento del Penn-Hip modificado y la sinfisiodesis juvenil pubiana como método para prevenir el desarrollo de la displasia de cadera canina. MATERIAL Y MÉTODO: Estudio descriptivo y ambispectivo que compara el porcentaje de displasia de cadera canina en una cohorte prospectiva, tras la realización de un programa de screening y cirugía profiláctica, con los resultados de una cohorte histórica. RESULTADOS: El porcentaje de displasia de cadera canina fue el doble en la cohorte histórica comparándola con la cohorte prospectiva tras la implantación del programa, siendo las diferencias estadísticamente significativas (OR: 2,20; IC 95%: 1,03-4,67). CONCLUSIONES: Es necesaria la instauración de programas de screening y profilaxis de displasia de cadera canina, en el ámbito militar al mejorar la producción de perros aptos para el trabajo en las Fuerzas Armadas y en los Cuerpos y Fuerzas de Seguridad del Estado

INTRODUCTION: Canine hip dysplasia is the main clinic cause of exclusion of dogs from training programs in the Armed Forces and Police Corps so it is important to make an early selection of this pathology. OBJECTIVE: To determine the efficiency of the modified Penn-Hip method and the juvenile pubic symphysiodesis as a way of preventing canine hip dysplasia development. MATERIAL AND METHOD: Ambispective descriptive study which compares the percentage of canine hip dysplasia between a historical cohort and a prospective cohort after the instauration of a screening and surgical prophylactic program. RESULTS: The percentage of canine hip dysplasia from the historical cohort doubled the one from the prospective cohort after carrying out the program, obtaining statistically significance differences (OR: 2,20; IC 95%: 1,03-4,67). CONCLUSIONS: Implementation of a screening and prophylactic program of canine hip dysplasia is needed to improve work-suited canine production in the Armed Forces and Police Corps

Lumbosacral transitional vertebrae, canine hip dysplasia, and sacroiliac joint degenerative changes on ventrodorsal radiographs of the pelvis in police working German shepherd dogs.

Lumbosacral transitional vertebrae (LTV) frequently occur in German shepherd dogs. The aim of the study was to evaluate the prevalence and interdependence between LTV and canine hip dysplasia (CHD) as well as sacroiliac joint degenerative changes visualized on ventrodorsal radiographs of the pelvis in both working and companion German shepherd dogs. The presence of LTV was found in 12% of working dogs and in 33% of companion dogs. Similar incidence of hip dysplasia in both the groups was found. It has been shown that dogs with LTV have a higher frequency of severe CHD. A higher percentage of sacroiliac joint degenerative changes was observed in dogs with no signs of LTV and in working dogs.

Genetic evaluation of the total hip score of four populous breeds of dog, as recorded by the New Zealand Veterinary Association Hip Dysplasia Scheme (1991-2011).

AIM: To use estimated breeding value (EBV) analysis to investigate the genetic trend of the total hip score (to assess canine hip dysplasia) in four populous breeds of dogs using the records from the New Zealand Veterinary Association (NZVA) Canine Hip Dysplasia Scheme database (1991 to 2011). METHODS: Estimates of heritability and EBV for the NZVA total hip score of individual dogs from the German Shepherd, Labrador Retriever, Golden Retriever and Rottweiler breeds were obtained using restricted maximum likelihood procedures with a within-breed linear animal model. The model included the fixed effects of gender, birth year, birth season, age at scoring and the random effect of animal. The pedigree file included animals recorded between 1990 and 2011. A total of 2,983 NZVA hip score records, from a pedigree of 3,172 animals, were available for genetic evaluation. Genetic trends of the NZVA total hip score were calculated as the regression coefficient of the EBV (weighted by reliabilities) on year of birth. RESULTS: The estimates of heritability for hip score were 0.32 (SE 0.08) in German Shepherd, 0.37 (SE 0.08) in Labrador Retriever, 0.29 (SE 0.08) in Golden Retriever and 0.52 (SE 0.18) in Rottweiler breeds. Genetic trend analysis revealed that only the German Shepherd breed exhibited a genetic trend towards better hip conformation over time, with a decline of 0.13 (SE 0.04) NZVA total hip score units per year (p<0.001). The genetic trends of total hip score for the remaining three breeds were not significantly different from zero (p>0.1). CONCLUSIONS: Despite moderate heritability of the NZVA total hip score, there has not been substantial improvement of this trait for the four breeds analysed in the study period. CLINICAL RELEVANCE: Greater improvement in reducing the prevalence of canine hip dysplasia may be possible if screening were to be compulsory as a requirement for registration of pedigree breeding stock, greater selection pressure were to be applied and selection of breeding stock made on the basis on an individual's EBV rather than the NZVA total hip score alone.

Combined prevalence of inherited skeletal disorders in dog breeds in Belgium.

Canine hip dysplasia (CHD), canine elbow dysplasia (CED), and humeral head osteochondrosis (HHOC) are inherited traits with uneven incidence in dog breeds. Knowledge of the combined prevalence of these three disorders is necessary to estimate the effect of the currently applied breeding strategies, in order to improve the genetic health of the population. Official screening results of the Belgian National Committee for Inherited Skeletal Disorders (NCSID) revealed that an average of 31.8% (CHD, CED, or both; n = 1273 dogs) and 47.2% (CHD, CED, HHOC, or a combination of these three diseases; n = 250 dogs) of dogs are mildly to severely affected by at least one skeletal disorder. According to the current breeding recommendations in some dog breeds in Belgium, these animals should be restricted (mild signs) or excluded (moderate to severe signs) from breeding. The introduction of genetic parameters, such as estimated breeding values, might create a better approach to gradually reduce the incidence of these complex inherited joint disorders, without compromising genetic population health.

The effects of positioning, reason for screening and the referring veterinarian on prevalence estimates of canine hip dysplasia.

Although the prevalence of canine hip dysplasia (HD) has been the subject of a number of published studies, estimates vary widely. This study evaluated several possible causes for these differences. Sixty Belgian, Dutch and German veterinarians were asked to submit all hip radiographs obtained for screening purposes (irrespective of HD status) over a 2-year period, resulting in a database of 583 dogs. Each set of radiographs was accompanied by information on the reason for screening (breeding soundness examination, clinical complaint, assistance dogs, or other reasons), and dog breed, date of birth and age. Dog positioning exerted an effect at multiple levels. The agreement among different observers regarding correct or incorrect positioning was limited and incorrect positioning itself reduced the inter-observer agreement for radiographic hip conformation. Dysplastic dogs were more commonly positioned incorrectly than non-dysplastic dogs. The clinical complaint population had a high prevalence of dysplastic dogs (>70%) compared with the breeding population (11%) and the assistance dogs (6%). There was a significantly lower prevalence of HD among cases referred by veterinarians who frequently submitted hip-extended radiographs for evaluation (P = 0.002) compared to those who refer less frequently. However, this was likely to be selection bias, as radiographs that were from dogs suspected to be dysplastic were not submitted by frequent senders. The prevalence of dysplastic dogs varied widely between breeds (16.7-71.4%). Dogs diagnosed with dysplasia were significantly older than dogs considered healthy (P = 0.001) and dogs classified as borderline dysplastic (P = 0.035). Inter-observer agreement for hip conformation was moderately low, resulting in >7% variation in prevalence estimates for dysplasia.

Prevalence and co-occurrence of hip dysplasia and elbow dysplasia in Dutch pure-bred dogs.

Hip as well as elbow dysplasia (HD, ED) are developmental disorders leading to malformation of their respective joints. For a long time both disorders have been scored and targeted for improvement using selective breeding in several Dutch dog populations. In this paper all scores for both HD and ED, given to pure bred dogs in the Netherlands from 2002 to 2010, were analyzed. Heritabilities and correlations between HD and ED were calculated for the 4 most frequently scored breeds. Heritabilities ranged from 0.0 to 0.37 for HD related traits (FCI-score, osteoarthritis, congruity, shape and laxity (Norberg angle); FCI: Fédération Cynologique Internationale) and from 0.0 to 0.39 for ED related traits (IEWG score, osteoarthritis, sclerosis and indentation; IEWG: International Elbow Working Group). HD related traits showed high genetic and residual correlations among each other but were only to a minor extent correlated with ED related traits, which also showed high correlations among each other. Genetic correlations were higher than residual correlations. Phenotypic and genetic trends since 2001 for the four most scored breeds were slightly positive but decreasing over time, indicating that selection over the past decade has not been effective.

Monitoring Hip and Elbow Dysplasia achieved modest genetic improvement of 74 dog breeds over 40 years in USA.

Hip (HD) and Elbow Dysplasia (ED) are two common complex developmental disorders of dogs. In order to decrease their prevalence and severity, the Orthopedic Foundation for Animals (OFA) has a voluntary registry of canine hip and elbow conformation certified by boarded radiologists. However, the voluntarily reports have been severely biased against exposing dogs with problems, especially at beginning period. Fluctuated by additional influential factors such as age, the published raw scores barely showed trends of improvement. In this study, we used multiple-trait mixed model to simultaneously adjust these factors and incorporate pedigree to derive Estimated Breeding Values (EBV). A total of 1,264,422 dogs from 74 breeds were evaluated for EBVs from 760,455 hip scores and 135,409 elbow scores. These EBVs have substantially recovered the reporting bias and the other influences. Clear and steady trends of genetic improvement were observed over the 40 years since 1970. The total genetic improvements were 16.4% and 1.1% of the phenotypic standard deviation for HD and ED, respectively. The incidences of dysplasia were 0.83% and 2.08%, and the heritabilities were estimated as 0.22 and 0.17 for hip and elbow scores, respectively. The genetic correlation between them was 0.12. We conclude that EBV is more effective than reporting raw phenotype. The weak genetic correlation suggested that selection based on hip scores would also slightly improve elbow scores but it is necessary to allocate effort toward improvement of elbow scores alone.

Worldwide screening for canine hip dysplasia: where are we now?

OBJECTIVE: To critically review the different screening systems used for canine hip dysplasia (CHD) and their impact on the prevalence of the disease. STUDY DESIGN: Critical literature review. METHODS: Literature search through PubMed (November 1959-October 2011) and the Orthopedic Foundation for Animals (OFA), Fédération Cynologique Internationale (FCI), British Veterinary Association/Kennel Club (BVA/KC), and Pennsylvania Hip Improvement Program (PennHIP) websites. RESULTS: The OFA, FCI, and BVA/KC screening methods, which use the hip-extended radiographic projection, have had relatively minor success on CHD prevalence. These screening approaches are prone to conflicting data regarding interobserver agreement. The PennHIP and Dorsolateral Subluxation (DLS) systems, both distraction methods, have not reported on prevalence but seem to be important heritable traits in genomic screening of dysplastic dogs. CONCLUSION: A shift towards genome screening yields a promising future combating CHD, although further investigation towards fine-mapping in the search for genes, responsible for CHD, is necessary.