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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.

Canine hip dysplasia (CHD) screening relies on accurate positioning in the ventrodorsal hip extended (VDHE) view, as even mild pelvic rotation can affect CHD scoring and impact breeding decisions. This study aimed to assess the association between pelvic rotation and asymmetry in obturator foramina areas (AOFAs) and to develop a computer vision model for automated AOFA measurement. In the first part, 203 radiographs were analyzed to examine the relationship between pelvic rotation, assessed through asymmetry in iliac wing and obturator foramina widths (AOFWs), and AOFAs. A significant association was found between pelvic rotation and AOFA, with AOFW showing a stronger correlation (R2 = 0.92, p < 0.01). AOFW rotation values were categorized into minimal (n = 71), moderate (n = 41), marked (n = 37), and extreme (n = 54) groups, corresponding to mean AOFA ± standard deviation values of 33.28 ± 27.25, 54.73 ± 27.98, 85.85 ± 41.31, and 160.68 ± 64.20 mm2, respectively. ANOVA and post hoc testing confirmed significant differences in AOFA across these groups (p < 0.01). In part two, the dataset was expanded to 312 images to develop the automated AOFA model, with 80% allocated for training, 10% for validation, and 10% for testing. On the 32 test images, the model achieved high segmentation accuracy (Dice score = 0.96; Intersection over Union = 0.93), closely aligning with examiner measurements. Paired t-tests indicated no significant differences between the examiner and model’s outputs (p > 0.05), though the Bland–Altman analysis identified occasional discrepancies. The model demonstrated excellent reliability (ICC = 0.99) with a standard error of 17.18 mm2. A threshold of 50.46 mm2 enabled effective differentiation between acceptable and excessive pelvic rotation. With additional training data, further improvements in precision are expected, enhancing the model’s clinical utility.

Abstract Background Canine hip dysplasia is a common orthopedic disease in veterinary practice. The diagnosis is made by radiographic examinations that evaluate bone alterations associated with hip dysplasia. Although radiographic examination is the gold standard for diagnosis, it does not allow a detailed evaluation of soft tissues such as the joint capsule and periarticular muscles. This study aimed to evaluate the accuracy of B-mode ultrasonography and acoustic radiation force impulse (ARFI) elastography in assessing the joint capsule and periarticular muscles of dogs using the Orthopedic Foundation of Animals (OFA) classification and the distraction index (DI) in the early and late diagnosis of hip dysplasia. This study sought to propose a protocol for the ultrasonographic evaluation of the structures involved in canine hip dysplasia. Methods Radiographic and ultrasonographic evaluations were performed on 108 hip joints of 54 dogs. Thirty dogs were older than 2 years and 24 were aged between 4 and 10 months. Results It was verified that an increase in pectineus muscle stiffness (cutoff value > 2.77 m/s) by elastography in some dysplastic dogs and an increase in the thickness of the joint capsule (cutoff value > 0.9 mm) in B-mode ultrasonography, were associated with a distraction index > 0.5, with both having a positive correlation. In B-mode ultrasonographic evaluation, the presence of signs of degenerative joint disease, such as irregularities of the cranial edge of the acetabulum and femoral head, were associated with a distraction index > 0.5 in canines, with a specificity of 94%. In adult dogs, the findings of degenerative joint disease on ultrasound were associated with a diseased OFA classification (P 1.10 mm was diagnostic for dysplasia in unhealthy dogs by OFA. Conclusions ARFI elastography has shown that the pectineus muscle may experience changes in stiffness in dysplastic animals. Additionally, changes in joint capsule thickness can be identified in B-mode in young and adult dogs with dysplastic joints, which contributes to the diagnosis of hip dysplasia.

Background and Aim: Passive hip laxity (PHL) is considered the primary risk factor for canine hip dysplasia (HD) and is estimated, in stress hip radiographs, using the distraction index (DI). The study aimed to associate the early PHL using the hip Distractor of University of Trás-os-Montes and Alto Douro (DisUTAD) and the late HD grades. Materials and Methods: A total of 41 dogs (82 hips) were submitted to a follow-up study. First, between 4 and 12 months of age, dogs were radiographed using the DisUTAD hip distractor and were determined the DI for each hip joint. Then, after 12 months of age, dogs were reevaluated for HD using the conventional hip ventrodorsal projection and hips were evaluated for HD using the Fédération Cynologique Internationale (FCI) scoring system. Results: Hips of dogs' in the second examination with FCI grades of A (n=28), B (n=11), C (n=22), and D and E (n=21) had an early DI of 0.32±0.1, 0.38±0.08, 0.50±0.12, and 0.64±0.11, respectively. Statistical analysis using the general linear model univariate, with the DI as dependent variable and the FCI grades, side and sex as fixed factors, and the post hoc Bonferroni correction test showed significant differences among FCI grades (p

Canine hip dysplasia (CHD) is a common orthopedic disease. Owing to the importance of CHD in affected dogs, both clinically and for their use in breeding or work, increasing attention is being given to early diagnosis. Therefore, early clinical and radiological examination of young animals is increasingly in demand, whereas common CHD screening according to the Fédération Cynologique Internationale (FCI) is usually performed at the age of 12 months or even older in Europe. One way to objectively evaluate gait pattern is to measure the ground reaction forces (GRFs) and center of pressure (COP). In this study, we used a pressure plate to evaluate the GRF and COP parameters for 32 Labrador Retrievers and 17 Golden Retrievers at 4, 8, and 12 months of age. The dogs also underwent radiological examination of the hip joints following the FCI rules at the age of at least 12 months, which were grouped as sound (FCI grade A or B) and diseased (FCI grade C or worse). The results revealed significantly higher COP values in both breeds in the diseased limb groups at any measurement point during walking, with the most pronounced results obtained at 8 months of age. Furthermore, COP values during walking were significantly higher at 4 months than at 8 and 12 months in both the sound and diseased limb groups, indicating an increased stability of the gait pattern. Except for COP-Speed, the values of all COP parameters were higher during walking than during trotting at 4 months of age (i.e., COP-Speed was higher when trotting), indicating that the 4-beat gait in walk is more difficult to control for puppies than the 2-beat gait in trot. Overall, our results support the early evaluation of CHD in growing animals using non-invasive methods.

The present paper is a bibliographical research on canine hip dysplasia using imaging and molecular genetics techniques. Ever since the first description in 1935 made by Schnelle, canine hip dysplasia has remained one of the most diagnosed orthopedic conditions present in the dog breeds. The gold standard method of diagnosis of hip dysplasia is the radiological examination in hip-extended position. While the radiological examination focuses mainly on the individual for the diagnosis of this condition, methods of diagnosis of an entire population are sought, and these methods are represented by molecular genetics techniques. Naming the etiology of canine hip dysplasia and finding out the latest methods of genetically and radiologically diagnosis of canine hip dysplasia and the best alternatives of treatment for this disease. Canine hip dysplasia continues to be a major problem for owners, breeders and veterinarians. Currently, there are five standardized systems worldwide that deal with the grading of canine hip dysplasia. In addition to digital radiology, CT and ultrasonographic examination are feasible diagnosis methods. Even if the standard method of diagnosis remains the radiological examination in the present, the near future provides to be of the molecular genetic techniques.

The alteration in the shape of the femoral neck is an important radiographic sign for scoring canine hip dysplasia (CHD). Previous studies have reported that the femoral neck thickness (FNT) is greater in dogs with hip joint dysplasia, becoming progressively thicker with disease severity. The main objective of this work was to describe a femoral neck thickness index (FNTi) to quantify FNT and to study its association with the degree of CHD using the Fédération Cynologique Internationale (FCI) scheme. A total of 53 dogs (106 hips) were randomly selected for this study. Two examiners performed FNTi estimation to study intra- and inter-examiner reliability and agreement. The paired t-test, the Bland-Altman plots, and the intraclass correlation coefficient showed excellent agreement and reliability between the measurements of the two examiners and the examiners’ sessions. All joints were scored in five categories by an experienced examiner according to FCI criteria. The results from examiner 1 were compared between FCI categories. Hips that were assigned an FCI grade of A (n = 19), B (n = 23), C (n = 24), D (n = 24), and E (n = 16) had a mean ± standard deviation FNTi of 0.809 ± 0.024, 0.835 ± 0.044, 0.868 ± 0.022, 0.903 ± 0.033, and 0.923 ± 0.068, respectively (ANOVA, p < 0.05). Therefore, these results show that FNTi is a parameter capable of evaluating proximal femur bone modeling and that it has the potential to enrich conventional CHD scoring criteria if incorporated into a computer-aided diagnosis capable of detecting CHD.

Canine hip dysplasia is characterized by joint instability, subluxation, or even luxation of the femoral head, which causes a deformation of the joint with the early production of coxarthrosis. The main purpose of the paper was to determine the incidence of canine hip dysplasia from October 2019 until June 2021 in the Faculty of Veterinary Medicine in Cluj-Napoca. A total of 173 X-rays on the canine hips were taken between October 2019 and June 2021 in the Radiology Department of the Faculty of Veterinary Medicine from Cluj-Napoca. X-rays were taken with the Roentgen TEMCO Grx machine, then imported into the RadiAnt DICOM™ program, and interpreted according to the FCI grading scheme. A total number of 88 X-rays were excluded due to different causes, thus our study presents 85 X-ray images of the hip from different breeds of dogs. From a total of 85 dogs presented in this study, 38 dogs were graded A, 10 dogs were graded B, 22 dogs were classified with grade C, with grade D were classified 6 dogs and with grade E were diagnosed 9 dogs. Out of 85 dogs examined (49 males and 36 females) more than half (N=48; 56,5%) were free from canine hip dysplasia. [ABSTRACT FROM AUTHOR]

ABSTRACT: Canine hip dysplasia (CHD) is a common condition observed in the surgical clinics for small animals. Among the surgical techniques for management of CHD, triple pelvic osteotomy and sacroiliac wedge promote acetabular lateral axial rotation (ventroversion), increasing acetabular coverage and joint stability. The present study aimed to evaluate radiographically, by measuring the Norberg angle (NA) and the acetabular coverage percentage (ACP), the acetabular ventroversion induced by the sacroiliac wedge technique, with or without pelvic osteotomies; we also checked the feasibility of wedges made of polyamide with an angulation of 20° and 30°. The software used to measure NA and ACP was AutoCAD® 2009. Pelves from 10 canine corpses were evaluated radiographically at four time-points: M0 (Control Group), M1 (wedges of 20° and 30°), M2 and M3 (wedges associated with bilateral pubis and ischium osteotomies, respectively). There was no significant increase in the acetabular ventroversion at M1, M2, and M3. The polyamide sacroiliac wedge technique proved to be feasible, stable, and easy to apply. Further, the software proved to be efficient and easy to use for NA and ACP measurements. In the present study, even in the cases of non-dysplasic adult canine corpses, it was concluded that the sacroiliac wedge technique does not require to be accompanied by pubis and ischial osteotomies because they did not significantly increase the NA and ACP.

Hip dysplasia (HD) is an important hereditary orthopedic disease in the dog associated with osteoarthritis and inadequate welfare for affected animals. The radiographic ventrodorsal hip extended (VDHE) view is used worldwide to select the better animals for breeding. This view normally is performed with manual restraining of the dog to obtain radiographs with acceptable technical quality. The veterinarian exposition to ionizing radiation is inevitable. In this study, the technical quality of VDHE radiographs and hip measurements was compared in 65 dogs radiographed twice, one with the common veterinarian manual restraining and the other obtained using a hind limb holder device, without the veterinarian within the X-ray room. The variables studied were pelvic tilting, patella displacement index, Norberg angle (NA), and subluxation hip category. The results showed a random distribution of right and left pelvic tilting, patella lateral or medial displacement, and hip subluxation categories in both samples (P > 0.05). The holder device positioning showed a better pelvic symmetry (P < 0.05) and a similar patellar displacement (P > 0.05). The mean ± standard deviation of NA was 101.1° ± 6.2° and 100.9° ± 6.1° in the manual and holder device hind limb restraining, respectively (P > 0.05), and the lower limit of 95% confidence interval of intraclass correlation coefficient was >0.75. These results showed statistical reproducibility of NA measurements by the hind limb holder device, and the examiner was protected from exposure to ionizing radiation within the X-ray room.

Canine hip dysplasia is a complex and multifactorial disease. The early diagnosis of dysplastic dogs under one year of age helps veterinarians to plan proper preventive/therapeutic methods. Having an accurate screening method increases the chance of the early detection of dysplasia. The goal of our study was to assess the inter-observer reliability of eight radiographic parameters in four-month-old Rottweilers. Radiographs of the 28 Rottweilers were investigated by five experienced observers. The radiographs were taken in ventrodorsal view with extended legs, frog-leg ventrodorsal view, distraction view, and dorsal acetabular rim view. Four quantitative parameters such as Norberg angle (NA), distraction index (DI), dorsal acetabular rim slope (DARS), and center edge angle (CEA) and four qualitative parameters such as sclerosis of the cranial acetabular rim (SCAR), location of the center of the femoral head (LCFH), grading of the degenerative joint disease (GDJD), and grading of the dorsal acetabular rim (GDAR) were evaluated. High inter-observer agreements were recorded for quantitative values, whereas the inter-observer agreement of the qualitative parameters was low. It can be deduced that the evaluated quantitative parameters are reliable, and a combination of these methods with clinical examinations might increase the accuracy of the examinations.

Canine hip dysplasia (CHD) is a genetic disease, modulated by epigenetic and environmental factors. To decrease the prevalence of CHD, the hip joints of many pure breed dogs are radiographed to identify dysplastic dogs not qualified for breeding. It has been shown that both, prevalence and severity of CHD may be reduced on the basis of phenotypic i.e., radiographic selection of breeding animals. The method has been used in many countries for over 50 years. In the present study, severity and prevalence of CHD in five common large breeds in Switzerland were evaluated since 1995. Both, prevalence and severity of CHD dropped in each breed between the periods 1995–1999 and 2010–2016. The prevalence decreased in Golden Retrievers from 25 to 9% and in Labrador Retrievers from 16 to 3%, respectively. In the Flat-Coated Retriever, prevalence in general was low, decreasing from 6 to 3%. In the Bernese mountain dog and the German shepherd dog, a decrease from 21 to 12% and from 46 to 18%, respectively, was observed. However, the rather low overall rate of radiographed dogs (Retrievers: 11 to 18%, Bernese Mountain dogs: 23% and German Shepherd dogs: 31%) does not allow to draw reliable conclusions regarding the true prevalence of CHD for the entire population of these breeds in Switzerland.

Canine hip dysplasia (CHD) is a common disease representing an important problem for many dog breeds worldwide. The screening for CHD and breeding programs have been ongoing for many decades but the incidence of disease have failed to be reduced to the expected level. The early diagnosis of CHD is paramount in order to facilitate the early management strategies and to prevent the breeding of the affected individuals. Generally in this area, the emphasis is placed on the radiographic evaluation process, however this is partly a subjective process suggested to be influenced by the experience of the observers. This study was designed to evaluate the interobserver agreement in CHD evaluation based on the Federation Cynologique International system (FCI system). Ten original radiographs were sent to five different groups of observers, from students to certified veterinarians. They were asked to evaluate the ventro-dorsal radiographs according to the FCI system which is the most common system used in Europe to give the final grades (A, B, C, D, E). The grades were converted to numbers and the data were analysed using a one-way ANOVA test. The results showed that only in 20% of the cases, the interobserver agreement was statistically higher in the group of the most experienced observers when compared to the less experienced group of observers. This means that the level of experience does not always lead to a higher agreement. This could be a problem of widespread objective evaluations of CHD. In addition, there are several different systems of evaluation used in various countries. It is necessary to understand the intention of dog owners, who when buying a dog may be planning its first breeding. Therefore, the “correct” or “incorrect” assessment of the CHD radiographs may not always result in the elimination of affected individuals. We do not know exactly the situation of the development of the hip in some breeds, because scrutineers are receiving only “negative radiographs” for evaluation. Many owners are very educated about hip and elbow dysplasia. It is a time to tell the scientific truth.

Canine hip dysplasia is a multifactorial disorder characterized by hip laxity and osteoarthritis. The early diagnosis of hip laxity is an important topic in small animal orthopedics. This study aimed to evaluate the correlation between clinical orthopedic examinations and the Fédération Cynologique Internationale (FCI) scoring method. Thirty purebred Rottweilers were examined at approximately four (20 ± 2 weeks), eight (35 ± 2 weeks), and twelve months of age (54 ± 1 weeks), respectively. The Ortolani, Barlow, and Bardens tests and reduction/subluxation angle measurements were performed at each time. FCI scoring was conducted at the third examination time. Positive correlations were recorded between the reduction angle and Ortolani test, reduction angle and FCI score, and Ortolani test and FCI score for the second and third examination dates. No correlation was observed between the subluxation angle and other methods. Despite previous studies reporting 16–20 weeks as the earliest age for diagnosing hip laxity in dogs, in our study, early diagnosis was possible from the age of 35 ± 2 weeks. This difference might originate from the small sample size, low number of the dogs with severe grades of laxity, and breed differences.

An Alaskan Malamute (2-year-old, castrated male, 41kg) was referred with bilateral hind limb lameness. The dog had a history of a bilateral triple pelvic osteotomy (TPO) to correct hip dysplasia one year previously, a surgery that was unsuccessful. On physical examination, pain and crepitus were noted in both hip joints. There was hip joint subluxation and mild degenerative changes bilaterally seen by radiograph. A Zurich cementless total hip replacement (ZCTHR) was planned for the right hind limb. After a craniolateral approach, an acetabular cup and a cementless femoral stem were implanted. The femoral head was placed in the femoral stem, and the prosthetic joint was then reduced. At a 9 month postoperative checkup, there was no pain on palpation or manipulation of the right pelvic limb, and the range of motion was within normal limits. On radiological examination, there was no implant loosening. The ZCTHR can thus be applied in a failed TPO patient as a revision surgery.

Canine hip dysplasia (CHD) is a common problem in veterinary medicine. We report the demographics of CHD using the entire hip dysplasia registry from the Orthopedic Foundation for Animals, analyzing differences by breed, sex, laterality, seasonal variation in birth, and latitude. There were 921,046 unique records. Each dog was classified using the American Kennel Club (AKC) and F'ed'eration Cynologique Internationale (FCI) systems. Statistical analysis was performed with bivariate and logistic regression procedures. The overall CHD prevalence was 15.56%. The OR for CHD was higher in females (1.05), those born in spring (1.14) and winter (1.13), and those in more southern latitudes (OR 2.12). Within AKC groups, working dogs had the highest risk of CHD (OR 1.882) with hounds being the reference group. Within FCI groups, the pinscher/molossoid group had the highest risk of CHD (OR 4.168)with sighthounds being the reference group. The similarities betweenCHD and DDH are striking. Within DDH there are two different types, the typical infantile DDHand the late onset adolescent/adult acetabular dysplasia, with different demographics; the demographics of CHD are more similar to the later onset DDH group. Comparative studies of both disorders should lead to a better understanding of both CHD and DDH. [ABSTRACT FROM AUTHOR]

The article presents information on veterinary diagnosis of hip dysplasia and a torn cruciate ligament. Topics discussed include how to differentiate between these two orthopedic problems; the severity of lameness that depends on the severity of ligament disruption; and orthopedic examination showing various degrees of stifle pain with flexion and extension and variable crepitus.

Totally 121 cases of hip dysplastic dogs were reviewed. Hip dysplasia was most frequently found in young and large breeds and highest incidence was seen in the age group of about one to six months (34.71%). The breed-wise incidence was more common in Labrador retriever (29.75%). Male dogs were found to be more affected (65.28%) than female dogs (34.71%). Bilateral hip dysplasia was found to be more (64.46%) than unilateral. Among the unilateral hip dysplasia, Right side (62.79%) was more common than left side (37.20%). [ABSTRACT FROM AUTHOR]

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 interobserver 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. [ABSTRACT FROM AUTHOR]

Canine hip dysplasia (CHD) is the most common hereditary skeletal disorder in dogs. To identify common alleles associated with CHD, we genotyped 96 German Shepherd Dogs affected by mild, moderate and severe CHD and 96 breed, sex, age and birth year matched controls using the Affymetrix canine high density SNP chip. A mixed linear model analysis identified five SNPs associated with CHD scores on dog chromosomes (CFA) 19, 24, 26 and 34. These five SNPs were validated in a by sex, age, birth year and coancestry stratified sample of 843 German Shepherd Dogs including 277 unaffected dogs and 566 CHD-affected dogs. Mean coancestry coefficients among and within cases and controls were <0.1%. Genotype effects of these SNPs explained 20–32% of the phenotypic variance of CHD in German Shepherd Dogs employed for validation. Genome-wide significance in the validation data set could be shown for each one CHD-associated SNP on CFA24, 26 and 34. These SNPs are located within or in close proximity of genes involved in bone formation and related through a joint network. The present study validated positional candidate genes within two previously known quantitative trait loci (QTL) and a novel QTL for CHD in German Shepherd Dogs. [ABSTRACT FROM AUTHOR]

Perfect hip joints are rarely found in the dog population as some degree of canine hip dysplasia is present in most dogs. In this article, the theory and methodology of the PennHIP technique is described and compared with the British Veterinary Association/Kennel Club Hip Dysplasia Scheme. [ABSTRACT FROM AUTHOR]

Hip dysplasia, an abnormal laxity of the hip joint, is seen in humans as well as dogs and is one of the most common skeletal disorders in dogs. Canine hip dysplasia is considered multifactorial and polygenic, and a variety of chromosomal regions have been associated with the disorder. We performed a genome-wide association study in Dutch Labrador Retrievers, comparing data of nearly 18,000 single nucleotide polymorphisms (SNPs) in 48 cases and 30 controls using two different statistical methods. An individual SNP analysis based on comparison of allele frequencies with a χ2 statistic was used, as well as a simultaneous SNP analysis based on Bayesian variable selection. Significant association with canine hip dysplasia was observed on chromosome 8, as well as suggestive association on chromosomes 1, 5, 15, 20, 25 and 32. Next-generation DNA sequencing of the exons of genes of seven regions identified multiple associated alleles on chromosome 1, 5, 8, 20, 25 and 32 (p<0.001). Candidate genes located in the associated regions on chromosomes 1, 8 and 25 included LAMA2, LRR1 and COL6A3, respectively. The associated region on CFA20 contained candidate genes GDF15, COMP and CILP2. In conclusion, our study identified candidate genes that might affect susceptibility to canine hip dysplasia. These genes are involved in hypertrophic differentiation of chondrocytes and extracellular matrix integrity of basement membrane and cartilage. The functions of the genes are in agreement with the notion that disruptions in endochondral bone formation in combination with soft tissue defects are involved in the etiology of hip dysplasia. [ABSTRACT FROM AUTHOR]

The article discusses a study which explored whether there is a seasonal variation in the hip score of dogs born in New Zealand using the New Zealand Veterinary Association (NZVA) canine hip dysplasia (CHD) scheme. Researchers evaluated data from dogs born between 1988 and 2009. They found that the month of birth had an effect on total and subtotal NZVA CHD scores. The possible environmental effect of weather and/or another seasonal factor on the phenotype of the coxofemoral joint is noted.

The purpose of this study is to evaluate of pre- and postoperative clinical and radiological outcomes of 3-5 month-old, 10 dogs with hip dysplasia after juvenile pubic symphysiodesis. Pain scoring of hip extension test, Ortolani signs and Bardens palpations were performed pre- and postoperatively, on 1st, 3rd, and 6th months by clinical examinations. Norberg-Olsson angles on standard ventrodorsal on extended radiological views and distraction index on distracted hip radiological views were evaluated by radiological examinations. Juvenile pubic symphysiodesis was applied every 2.0 to 3.0 mm among to the entire length of the growth plate of the pubis via unipolar needle electrocautery (40 W, for 12 to 30 seconds). Acetabular full coverage on the femoral head was provided as a result of ventrolateral rotation of the acetabulum following juvenile pubic symphysiodesis procedure. The hip extension test, Ortolani signs and Bardens palpations were turned from positive to negative. In conclusion, juvenile pubic symphysiodesis is a successful and safe procedure which can be easily applied for prophylaxis and/or treatment of hip dysplasia (HD) in 3-5-month-old, large-breed puppies, which are predisposed to hip dysplasia or showing the initial clinical signs of hip dysplasia. [ABSTRACT FROM AUTHOR]

The article presents a study which examined whether there has been considerable improvement in the phenotypic hip dysplasia status in four susceptible dog breeds as measured by the New Zealand Veterinary Association (NZVA) Canine Hip Dysplasia scheme. A retrospective analysis of the NZVA on records of all four dog breeds that were evaluated for hip dysplasia was conducted. The impact of date of birth on total hip score was determined. No significant improvement in three out of the four breeds was found.

Abstract: Our objective was to evaluate the association between grading of hip status as assessed by radiographic examination (hip screening) and subsequent incidence of veterinary care and mortality related to hip dysplasia (HD) in five breeds of insured dogs in Sweden. Screening results for hip status from the Swedish Kennel Club and data on veterinary care and mortality from the insurance company Agria were merged based on the registration number of the dog. Dogs of five breeds (Bernese Mountain Dogs, German Shepherds, Golden Retrievers, Labrador Retrievers, and Rottweilers) screened during 1995–2004 and covered by an insurance plan for veterinary care or life at the time of screening were included. The study populations included between 1667 and 10,663 dogs per breed. Breed-specific multivariable Cox proportional-hazards analyses were performed to evaluate the impact of radiographic hip status on time from hip screening to first HD-related veterinary and life claim, respectively. The effects of gender, birth season, and a time-varying covariate of year were also studied. Additional analyses, on the five breeds combined, were performed to investigate the effects of hip status, breed, and the interaction between hip status and breed. The effect of hip status was highly significant (P <0.001) for both life and veterinary claims related to HD in all five breeds with increased hazard ratio (HR) for deteriorating hip status. Dogs with moderate or severe hip status at screening had a markedly increased hazard of HD-related veterinary care and mortality compared with dogs assessed as free or mild. The time-varying covariate of year showed a significantly higher HR in the last time period for German Shepherds and Labrador Retrievers in the analyses of veterinary claims. In the analyses on all five breeds, German Shepherds had the highest HR for both veterinary care and mortality related to HD, followed by Bernese Mountain Dogs. Golden and Labrador Retrievers had the lowest HR. The effect of hip status on the hazard was the same irrespective of breed. However, as a consequence of differences between breeds in overall risk, the predictive ability of screening results for subsequent incidence of HD-related problems for individual dogs was breed-dependent. Based on the strong association between radiographic hip status and incidence of HD-related veterinary care and mortality, and the previously reported moderate heritability of hip status, we conclude that selection based on screening results for hip status can be expected to reduce the risk of HD-related clinical problems. [Copyright &y& Elsevier]

Objective--To evaluate the precision, reproducibility, and clinical usefulness of measuring the Norberg angle (NA) by means of a computerized system of image analysis. Sample Population--1,182 consecutive radiographs of hip joints of various breeds of dogs assessed for hip dysplasia and 72 radiographs of hip joints of German Shepherd Dogs. Procedures--Radiographs were assessed by a panel of 4 experts in consensus, and NAs were measured by means of a computerized system. Results of classification of hip dysplasia according to the Fédération Cynologique Internationale (FCI) and NAs were compared within dogs and among breeds. Results--Measurement of the NA by means of image analysis was twice as reproducible as that via calipers. Mean NA of left hip joints was 0.38° higher than that of right hip joints. The NA values accurately discriminated between hip joints of dogs without or with hip dysplasia, provided the values were also expressed as percentile rank based on the cumulative frequency distribution of NAs within the breed, and had good power to discriminate among various FCI classifications of hip joints. Mean NA for each dog breed as calculated by use of the lower of 2 NAs for each dog was highly variable and was moderately correlated with the existence of hip dysplasia (r = 0.5). Conclusions and Clinical Relevance--Computer-assisted measurement of the NA was useful in assessing hip joint quality and can be implemented for quality control and standardization of the FCI classification and for international comparisons. (Am J Vet Res 2009;70:228--235) [ABSTRACT FROM AUTHOR]

Objective—To evaluate prevalence of and risk factors for hip dysplasia (HD) and cranial cruciate ligament deficiency (CCLD) in dogs and determine change in prevalence over time. Design—Cross-sectional study. Animals—1,243,681 dogs for which information was reported to the Veterinary Medical Database between 1964 and 2003. Procedures—Information on breed, sex, and age was collected, and prevalences and odds ratios were calculated. Results—Castrated male dogs were significantly more likely than other dogs to have HD (odds ratio [OR], 1.21), and castrated male (OR, 1.68) and spayed female (OR, 2.35) dogs were significantly more likely to have CCLD. Dogs up to 4 years old were significantly more likely to have HD (OR for dogs 2 months to 1 year old, 1.22; OR for dogs> 1 to 4 years old, 1.48), whereas dogs > 4 years old were significantly more likely to have CCLD (OR for dogs > 4 to 7 years old, 1.82; OR for dogs > 7 years old, 1.48). In general, large- and giant-breed dogs were more likely than other dogs to have HD, CCLD, or both. Prevalences of HD and CCLD increased significantly over the 4 decades for which data were examined. Conclusions and Clinical Relevance—Results suggested that sex, age, and breed were risk factors for HD, CCLD, or both in dogs and that prevalences of HD and CCLD have increased over time. [ABSTRACT FROM AUTHOR]

Objective--To determine the accuracy of asymmetry indices of ground reaction forces (GRF) for diagnosis of hind limb lameness in dogs. Animals--36 healthy dogs and 13 dogs with naturally acquired cranial cruciate ligament rupture or hip dysplasia. Procedures--Lameness for affected dogs ranged from not detectable to minor and constant. While dogs trotted on an instrumented treadmill, GRF variables were recorded and analyzed with asymmetry indices. Each index was tested for its ability to discriminate between healthy and affected dogs. Combinations of several indices were also assessed. Results--Vertical force variables had better accuracy than craniocaudal force variables. Peak vertical force was the most accurate variable. Partial asymmetry during trotting was detected in healthy dogs. A multivariate approach that used peak vertical force and maximal rising slope yielded the optimum combination to distinguish between healthy and affected dogs. In addition, sensitivity of 92% or specificity of 95% may be achieved with 2 cutoff values while simultaneously maintaining specificity or sensitivity, respectively, at > 85%. Conclusions and Clinical Relevance--Asymmetry indices of GRFs were accurate for detection of hind limb lameness in dogs. This is particularly relevant for study designs in which only a single gait evaluation is possible. [ABSTRACT FROM AUTHOR]

Objective—To determine the relationship between a circumferential femoral head osteophyte (CFHO) and osteoarthritis characteristic of canine hip dysplasia, and to ascertain whether CFHO, like osteoarthritis, varies between diet-restricted and control-fed dogs. Design—Longitudinal cohort study. Animals—48 Labrador Retrievers. Procedures—Dogs were paired by size, sex, and litter and assigned to 1 of 2 equal groups at 2 months of age. The control-fed group was fed ad libitum, and the diet-restricted group was fed 25% less on a pairwise basis of the same diet for life. The dogs' hip joints were radiographed yearly for life. Each radiograph was evaluated for radiographic signs of osteoarthritis characteristic of hip dysplasia and for the presence and severity of a CFHO. Results—41 of the 48 (85.4%) dogs had a CFHO, which was detected at a median age of 5.4 years, and 33 of those 41 (80.5%) developed radiographic evidence of osteoarthritis. Nineteen (79.2%) dogs in the diet-restricted group and 22 (91.7%) in the control-fed group had a CFHO at a median age of 9 and 3 years, respectively. Of the dogs with a CFHO, 12 (63.2%) in the diet-restricted group and 20 (90.0%) in the control-fed group developed radiographic evidence of osteoarthritis characteristic of hip dysplasia at a median age of 11 and 6.5 years, respectively. Conclusions and Clinical Relevance Results indicated a relationship between the CFHO and subsequent development of radiographic signs of osteoarthritis. If a CFHO is present in Labrador Retrievers, it might be considered an early indicator of osteoarthritis. [ABSTRACT FROM AUTHOR]

Objective--To detect changes in joint kinematics of clinically sound dogs with or without radiographically detectable borderline hip dysplasia (HD). Animals--20 Belgian Shepherd Dogs (Malinois; mean ± SD age, 2.75 ± 1.32 years) with no clinical signs of HD. Procedures--Kinematic gait analysis was performed in Malinois walking on a treadmill. On the basis of results of radiographic examination for HD and in accordance with guidelines established by the Federation Cynologique Internationale, dogs were assigned to group 1 (no radiographic signs of HD; 8 dogs) or group 2 (borderline HD; 12 dogs). Ground reaction forces and weight distribution among limbs and differences between groups were evaluated. Maximal sagittal angle during the stance and swing phases, the time at which they were detected, and angle velocities were calculated for joints of the hind limbs. Results--Ground reaction forces revealed no differences between groups. Dogs in group 1 had significant changes (earlier time for maximal flexion of the hip joint and less flexion and less range of motion of the stifle joint), compared with results for dogs in group 2. Maximal angle velocity of the stifle and tarsal joints was significantly lower during the swing phase in group 1 than in group 2. Conclusions and Clinical Relevance--This study revealed that dogs with borderline HD had altered joint kinematics. Our data provide basic kinematic values for clinically sound and affected dogs and can be used to investigate the long-term effects for subclinical radiographic changes of the hip joints of dogs. [ABSTRACT FROM AUTHOR]

Objective—To investigate factors influencing screw loosening after triple pelvic osteotomy (TPO) and ischial wire stabilization of the acetabular segment. Design—Retrospective case series. Animals—227 dogs with congenital hip dysplasia or subluxated hip joints. Procedures—Medical records and radiographs of 227 dogs that underwent 332 TPO procedures were evaluated, and data pertaining to screw type, plate position, sacral screw engagement, use of ischial interfragmentary wires, and pelvic alignment were assessed for associations with screw loosening. Results—Complications developed in 96 of the 332 (29%) procedures. Cancellous screws without sacral engagement were associated with the lowest frequency (6%) of loosening, compared with cancellous and cortical screws engaging the sacrum and cortical screws that did not engage the sacrum. Frequency of screw loosening increased when cortical or cancellous screws engaged the sacrum and when cortical screws were used. In dogs that had surgery bilaterally, the first limb on which TPO was performed had a higher frequency of screw loosening than the second limb. Pelvic alignment loss was greatest (5.4°) when the 3 most cranial screws were loosened. Loss of pelvic alignment was significantly different between dogs that underwent surgery and had complications and those that underwent surgery and did not have complications in association with loosening of 1, 2, and 3 screws. Conclusions and Clinical Relevance—TPO screw loosening was multifactorial and related to stability of the affected ilium, screw type, and screw position. Placing cancellous screws that do not engage the sacrum in pelvic osteotomy plate positions 1 through 3 may decrease the number of screws that loosen. [ABSTRACT FROM AUTHOR]

Objective--To compare activities of interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, and matrix metalloproteinase (MMP)-3 and contents of sulfated glycosaminoglycan (S-GAG) in joint fluid obtained from dogs with hip dysplasia (HD) and clinically normal dogs, evaluate correlations among these markers in joint fluid obtained from dogs with HD, and evaluate correlations between each marker and clinical and radiographic variables. Animals--26 dogs with HD (clinical group) and 43 clinically normal Beagles (control group). Procedure--Joint fluid was aseptically collected from the hip joints of all dogs. For each dog in the clinical group, age, duration of tameness, radiographic osteoarthritis (OA) score, and Norberg angle in each affected joint were recorded. Activities of IL-1β, IL-6, TNF-α, and MMP-3 and S-GAG contents were measured. Values were compared between groups by use of Mann-Whitney U tests, and the Spearman rank correlation test was used to evaluate correlations among markers and between each marker and clinical or radiographic variables. Results--Values of all markers were significantly higher for the clinical group, compared with values for the control group. There was a moderate positive correlation between lameness duration and IL-6 activity and a strong negative correlation between the Norberg angle and IL-1β activity. Conclusions and Clinical Relevance--Analysis of our results indicated that there was a significant increase in markers of QA in dogs with HD. Activities of IL-1β and IL-6 in joint fluid of dogs with HD may be influenced by the severity of laxity in the hip joint and lameness duration, respectively. [ABSTRACT FROM AUTHOR]

Objective--To determine incidence, risk factors, and heritability estimates of hind limb lameness caused by hip dysplasia in a birth cohort of Boxers. Animals--l,733 Boxers from 325 litters. Procedure--Status of Boxers with respect to clinical signs of canine hip dysplasia (cCHD) was registered during an 8-year period. Survival analysis accounted for dogs lost to follow-up. Effective heritabitity for developing cCHD was estimated by use of a proportional hazard model on the basis of the Weibull distribution. Parametric survival models were developed to identify the influence of potential risk factors. Results--Cumulative hazard rate for cCHD from 7 weeks to 8 years of age was 8.5%. Dogs that were kept on a floor covered with a slippery material were 1.6 times as likely to develop cCHD, compared with dogs kept on a nonslippery floor. Risk of cCHD doubled in dogs from litters with a high preweaning mortality rate. Dogs that were neutered at 6 months prior to a diagnosis of CHD were 1.5 times as likely to develop cCHD, compared with sexually intact dogs. Dogs > 5 years of age were 1.8 times as likely to develop cCHD, compared with younger dogs. Estimated effective heritability of cCHD was 0.11. In terms of the risk of cCHD in progeny, mean estimated breeding value (EBV) of the 10 best and 10 worst sires was -0.32 and 0.42, respectively. Conclusions and Clinical Relevance--Registration of Boxers that develop cCHD may provide a strategy for disease prevention. In addition to diagnostic evaluation of radiographs, sire EBVs provide useful information for breeding selection decisions. [ABSTRACT FROM AUTHOR]

Objective-To determine the relationship between the caudolateral curvilinear osteophyte (CCO) and osteoarthritis associated with hip dysplasia in dogs. Design-Longitudinal cohort study. Animals-48 Labrador Retrievers from 7 litters. Procedure-In each of 24 sex- and size-matched pairs fed the same diet, a restricted-fed dog was fed 25% less than a control dog for life. The dogs' hips were evaluated in the standard ventrodorsal hip-extended radiographic projection at 16, 30, and 52 weeks of age and then yearly for life. Histologic examination of hip joint tissues was performed on 45 dogs. Results-Median age at death was 11.2 years. Adjusting for feeding group, dogs with a CCO were 3.7 times as likely to develop radiographic signs of osteoarthritis than those without a CCO. Stratified by diet, 100% of the control dogs with a CCO developed radiographic signs of osteoarthritis and 55% of restricted-fed dogs with a CCO developed radiographic signs of osteoarthritis. The CCO was the first radiographic change seen in 22 of 29 (76%) dogs with osteoarthritis. Overall, 35 of 37 (95%) dogs with a CCO had histopathologic lesions of osteoarthritis. Conclusions and Clinical Relevance-Results indicate a relationship between a CCO on the femoral neck and subsequent development of radiographic signs of osteoarthritis in Labrador Retrievers evaluated over their life span. [ABSTRACT FROM AUTHOR]

Summary Variance components and heritability were linearly estimated for canine hip dysplasia (CHD) in German Shepherd Dogs using a Bayesian analysis based on the marginal posterior distributions of parameters achieved via Gibbs sampling. Data was provided by the German Shepherd Breeding Association in Augsburg. The material included 21 371 X-rayed dogs born in the years 1998–2000 in 3755 kennels from 9704 litters. The pedigree file consisted of 38 604 animals and contained ancestors for up to six generations. The full model used considered the fixed effects of sex, age at examination for CHD, the examining veterinary expert, the combined effect of litter size and percentage of examined dogs per litter, and the sire and mother lines as well as the additive genetic random effects of the animal and of the mother, the permanent environmental effect of the litter and the kennel. Submodels were compared with the full model to evaluate the importance of different fixed and random effects, and their influence on other model components. Heritability estimates in the full model were h 2 = 0.26 ± 0.03 (additive genetic animal effect) and &formmu0; = 0.10 ± 0.02 (additive genetic maternal effect). The direct animal and the maternal effects were negatively correlated genetically (r am = -0.65 ± 0.05). The proportion of the variance of the random effect of the common kennel of the total variance was always below 0.015, whereas the corresponding proportion of variance of the random effect of the common litter effect reached a value of 0.045. When submodels were employed, the heritability estimates for the additive genetic animal effect ranged from h 2 = 0.24 to h 2 = 0.26. The heritability estimates for the additive genetic maternal effect varied between &formmu1; = 0.09 and &formmu2; = 0.10. [ABSTRACT FROM AUTHOR]

Objective-To determine the prevalence of cranial cruciate ligament rupture (CCLR) in dogs with lameness previously attributed to canine hip dysplasia (CHD). Design Retrospective study. Animals-369 client-owned dogs. Procedures-Hospital medical records from 1994 to 2003 were reviewed for dogs in which the referring veterinarian had diagnosed hip dysplasia or hip pain. Dogs were designated as having hind limb lameness because of partial or complete CCLR or CHD. Result-8% of dogs were sexually intact females, 43% were spayed females, 14% were sexually intact males, and 35% were castrated males. Mean age was 3.8 years (range, 3 months to 15 years). The most common breeds were the Labrador Retriever (21%), German Shepherd Dog (13%), and Golden Retriever (11%). The prevalence of CCLR as the cause of hind limb lameness was 32% (95% confidence interval, 272% to 36.8%). The distribution of CCLR among hind limbs was left (29%), right (28%), and bilateral (43%) Of 119 dogs with CCLR, 94% had concurrent radiographic signs of CHD, 92% had stifle joint effusion, and 81% had a cranial drawer sign. Conclusions and Clinical Relevance-On the basis of the high prevalence of CCLR in dogs referred for lameness because of CHD, it is important to exclude other sources of stifle joint disease before making recommendations for treatment of CHD. [ABSTRACT FROM AUTHOR]