Canine elbow dysplasia: Aetiopathogenesis and current treatment recommendations

The markers of the predictive DNA test for canine hip dysplasia may have a stronger relationship with elbow dysplasia

Canine hip and elbow dysplasias, which are prevalent orthopedic conditions rooted in developmental and hereditary factors are yet to be comprehensively assessed. This study aimed to address this gap by exploring the prognostic significance of five markers linked to canine hip dysplasia using available genome-wide association studies (GWAS) data. The influence of these markers on both hip and elbow dysplasia was examined in dogs exposed to standardized environmental conditions. We made a groundbreaking discovery using custom primers, qPCR assays, and evaluation of fluorescent resonance energy transfer (FRET) probes. Three specific SNPs previously associated with the risk of canine hip dysplasia demonstrated a potentially stronger correlation with elbow dysplasia. Notably, the SNP at nucleotide position 22691322, located near the canine CHST3 gene, displayed significance as a marker in multivariable logistic regression analysis. Surprisingly, none of the initially targeted SNPs showed a direct association with hip dysplasia. The genomic positions of these SNPs reside within a region conserved across mammals. In silico analyses suggested that the relevant variant might be positioned in a region linked to bone and muscle structures. Our findings revealed a remarkable relationship between SNP2 genotypes and methylation patterns, shedding light on the underlying mechanism that partially explains the genotype-phenotype correlation in canine CHST3. These groundbreaking findings offer essential insights for future, more extensive investigations into canine orthopedic health. This research significantly contributes to our understanding of the molecular foundations of hip and elbow dysplasia in dogs by charting a course for advancements in veterinary medicine and the overall well-being of canine companions.

Efficacy of a Single Injection of Stromal Vascular Fraction in Dogs with Elbow Osteoarthritis: A Clinical Prospective Study

This study aimed to assess the efficacy of a single intra-articular injection of autologous stromal vascular fraction (SVF) in dogs with chronic lameness due to advanced elbow osteoarthritis (OA) that were unresponsive to conventional drug therapy. In this clinical, prospective, non-blinded, single-center study, twenty-three dogs received autologous SVF derived from falciform adipose tissue. Primary outcome measures over the six-month study period included clinical-orthopedic and radiographic examinations, objective gait analysis and validated owner questionnaires. In 19 of 23 joints, no progression of OA was visible radiographically. Peak vertical force improved significantly at three months and vertical impulse at six months after the injection compared to baseline. Over 33% of dogs demonstrated treatment-related improvements in lameness based on objective gait analysis. Owner questionnaires indicated significant improvement in clinical signs throughout the study period and 26% of dogs showed treatment-related improvements in pain scores according to the Canine Brief Pain Inventory. No side effects were reported. These findings suggest that autologous regenerative cell therapy may provide a promising treatment option for dogs with advanced OA that do not respond to conventional drug therapy. However, the treatment did not improve the clinical symptoms in all dogs, so it cannot be recommended for all patients.

Pathology of the Proximal Radius in Juvenile Pugs

The aim of this study was to describe the physeal pathology of the proximal radius in four skeletally immature male Pugs. Physical examination, radiography, and computed tomography (CT) of the thoracic limbs were performed in all four dogs. Two Pugs were available for long-term follow-up and two Pugs were euthanatized after the diagnostic imaging results. Four male Pugs, aged between 6 and 7 months, were presented with a history of thoracic limb lameness lasting 2 to 3 months. Radiography and CT of the thoracic limbs showed irregularity of the proximal radial physes with varying degrees of radiolucency within the adjacent metaphyses. The pathology was associated with elbow joint incongruity and angular deformity of the antebrachium. Two dogs were euthanatized, one of which was autopsied, and histopathology of the proximal radius revealed bilateral physeal dysplasia. At long-term follow-up of the two surviving dogs, lameness had resolved. Radiography and CT scans of the thoracic limbs revealed normal bone opacity within the proximal radius and resolution of the radiolucent areas of the proximal radial physes. However, incongruity of the radioulnar joint remained. In this report, the resolution of identified physeal pathology at the proximal radius in juvenile Pugs demonstrates the potential for spontaneous remission despite the presence of notable radiographic changes.

Comparison of Hounsfield Units within the Humeral Trochlea and Medial Coronoid Process in a Population of Labrador X Golden Retriever Guide Dogs and Border Collies

OBJECTIVE

 The aim of this study was to determine if variations in Hounsfield units (HU) are present within the elbow between asymptomatic dogs of two breeds of dogs susceptible to elbow dysplasia.

STUDY DESIGN

 Guide Dogs and Border Collies that presented for routine computed tomography (CT) screening for elbow dysplasia prior to breeding were evaluated. All dogs had no documented history of lameness. Dogs diagnosed with CT as being free of elbow dysplasia were included. The CT images were randomized and assessed by three blinded observers. A standardised approach to CT image reconstruction to create consistent image planes was used. Hounsfield units were measured within a standardised region of interest (ROI) at the humeral trochlea and medial coronoid process. The minimum, mean and maximum HU within each ROI was recorded.

RESULTS

 Eighty-six elbows were included in the study with 32 Guide Dogs, and 11 Border Collies. Guide Dogs had significantly higher minimum (99.75 HU, 95% confidence interval [CI]: 15.02-184.48, p = 0.022), mean (115.09 HU, 95% CI: 80.53-149.64, p < 0.01) and maximum (74.00 HU, 95% CI: 44.58-103.42, p < 0.01) difference in HU within the medial coronoid process ROI, and significantly higher mean (146.49 HU, 95% CI: 100.12-192.87, p < 0.01) and maximum (147.77 HU, 95% CI: 102.57-192.97, p < 0.01) difference in HU within the humeral trochlea ROI.

CONCLUSION

 In this dataset breed variations in elbow HU were present between asymptomatic Guide Dogs and Border Collies. This needs to be considered in breeding screening programmes to avoid over-interpretation of elbow sclerosis, in the absence of elbow pathology.

Impact of arthroscopy on post-procedure intra-articular elbow injections: A cadaveric study

OBJECTIVE

To determine the influence of arthroscopy and injection volume on post-procedure intra-articular (IA) injection extravasation.

STUDY DESIGN

Ex vivo prospective study.

SAMPLE POPULATION

A total of 40 paired canine cadaver forelimbs.

METHODS

After radiographs and computed tomography (CT) scans with three-dimensional (3D) digital bone model reconstructions, elbows were randomly assigned to the arthroscopy or control group and randomly assigned to receive an IA injection of 2 or 4 mL of contrast. Elbow arthroscopy was performed on assigned specimens, followed by IA injections of contrast in all elbows, and imaging was repeated. 3D digital model volumes were compared. Images were interpreted and scored for extravasation by a radiologist unaware of treatment and volume assignments.

RESULTS

Based on CT images and regardless of treatment group, IA injections of 4 mL resulted in a mean extravasation score of 2.25 (SD 0.97) versus 1.55 (SD 1.05) (p = .02) for 2 mL IA injections. The change in 3D model volumes after IA injections was a mean of 13.2 cm3 (SD 5.85) after 4 mL injections, compared to 6.97 cm3 (SD 6.28) (p = .003) after 2 mL injections. On radiographic evaluation, but not CT, the mean extravasation scores were 2.45 (SD 1.15) for the arthroscopy group and 1.25 (SD 0.79) for the control group (p < .001).

CONCLUSION

A larger volume of IA injection resulted in higher CT extravasation scores and larger 3D volumes regardless of arthroscopic treatment.

CLINICAL SIGNIFICANCE

IA injections performed immediately after arthroscopy resulted in 50% or less extravasation, especially with a smaller IA injection volume.

Evaluation of subchondral bone cysts in canine elbows with radiographic osteoarthritis secondary to elbow dysplasia

OBJECTIVE

To investigate whether subchondral bone cysts (SBCs) were present in dogs with radiographic elbow osteoarthritis (OA) and to investigate their relationship with radiographic OA severity.

STUDY DESIGN

Retrospective cross-sectional study.

SAMPLE POPULATION

Thirty-eight Labrador retrievers (total of 76 elbows).

METHODS

Elbow computed tomography (CT) images of 18 young (≤2 years old) and 20 old (>2 years old) Labrador retrievers, which presented for elbow-associated lameness, were reviewed. Radiographic elbow OA was graded into four groups based on the largest osteophyte size on CT. The presence, number, and maximum diameter of SBCs were determined.

RESULTS

Subchondral bone cysts were only identified in elbows with osteophytic new bone formation. The number and size of SBCs were associated with radiographic OA severity (p < .001 and p = .041 respectively). Specifically, the rate at which SBCs were present increased for both moderate and severe OA in comparison with the mild OA (moderate OA RR = 2.46, 95% CI 2.08-2.92, p < .001; severe OA RR = 5.60, 95% CI 4.79-6.55, p < .001). For dogs with severe OA, there was an increased likelihood that their SBCs were larger than SBCs from dogs with mild OA (OR = 1.056, 95% CI 1.012-1.101, p = .012). No SBCs were observed in elbows without radiographic evidence of OA.

CONCLUSION

Subchondral bone cysts were identified as a feature of radiographic elbow osteoarthritis in Labrador retrievers, and their number and size were indicative of the presence and severity of radiographic elbow OA.

CLINICAL SIGNIFICANCE

Subchondral bone cysts are a potential imaging biomarker for quantitative assessment for canine OA.

Dogs with Bilateral Medial Coronoid Disease Can Be Clinically Sound after Unilateral Arthroscopic Fragment Removal-Preliminary Study

The purpose of this study was to assess the outcome of dogs with bilateral medial coronoid disease (MCD) treated with arthroscopic intervention for the clinically more severely affected side and conservative management for the contralateral side. The medical records of dogs with bilateral medial coronoid disease diagnosed using computed tomography (CT) and treated using arthroscopic intervention on one elbow and conservative management on the other elbow were retrospectively reviewed. The outcome evaluation included clinical re-examination; follow-up radiographic-visible osteophytic lesions; as well as sclerotic changes and Liverpool osteoarthritis in a dogs questionnaire. Data from 48 clinically affected elbow joints (24 dogs) with bilateral MCD diagnosed using CT were included. Every dog underwent arthroscopic intervention on the elbow joint, which was clinically more severely affected, and the other side was treated with conservative management. A fragment of the medial coronoid was diagnosed using CT in all elbows, whereas 19 elbows (39.4%) showed a dislocation of the fragment and the other 29 elbows (60.4%) did not. There are no findings regarding the radioulnar Incongruence. Initially, 86% of all radiographs had the same degree of osteophytes. At the time of follow-up, the arthroscopic-treated limbs had more severe radiological changes in comparison to the conservatively treated limbs. Lameness improved after arthroscopic therapy in walking. The conservative group showed a largely unchanged gait pattern. Radiological changes do not necessarily reflect the severity of clinical signs. Arthroscopic intervention showed an improvement of the clinical gait pattern, even though the radiographic changes worsened.

Long-term outcomes in dogs with elbow dysplasia, assessed using the canine orthopaedic index

BACKGROUND

Elbow dysplasia (ED) is an important cause of lameness in dogs. This study aimed to report long-term outcomes in dogs with elbow osteoarthritis.

METHODS

Demographic data, medical management, and scores from The American College of Veterinary Surgeons' Canine Orthopaedic Index (COI) were collected from owners of dogs radiographically screened for ED, graded as normal, mild, or moderate. Telephone interviews were performed in 2017 (Q1), followed by an email survey in 2020 (Q2). The association between ED grade and deterioration in COI scores over time was evaluated with logistic regression.

RESULTS

A total of 765 replies were collected for Q1 and 293 for Q2. At Q2, 222 dogs (76%) were alive, with a median age of 8 years (range 5-12 years). No association was found between ED and changes in COI score over time or between ED and survival (p = 0.071). Dogs with mild and moderate ED were treated with analgesic medications to a higher degree than dogs without ED (p < 0.05).

LIMITATIONS

Only owner-assed data were assessed; no clinical orthopaedic examination or follow-up radiographic evaluation was performed.

CONCLUSIONS

No association was found between the grade of ED and the worsening of clinical signs in dogs with elbow osteoarthritis.

Two Amnion-Derived Mesenchymal Stem-Cells Injections to Osteoarthritic Elbows in Dogs-Pilot Study

The aim of the study was to investigate the potential of cell-based regenerative therapy for elbow joints affected by osteoarthritis. Interest was focused on two intra-articular applications of amnion-derived mesenchymal stem cells (A-MSCs) to a group of different breeds of dogs with elbow osteoarthritis (13 joints). Two injections were performed 14 days apart. We evaluated synovial fluid biomarkers, such as IFN-γ, IL-6, IL-15, IL-10, MCP-1, TNF-α, and GM-CSF, by multiplex fluorescent micro-bead immunoassay in the treated group of elbows (n = 13) (day 0, day 14, and day 28) and in the control group of elbows (n = 9). Kinematic gait analysis determined the joint range of motion (ROM) before and after each A-MSCs application. Kinematic gait analysis was performed on day 0, day 14, and day 28. Kinematic gait analysis pointed out improvement in the average range of motion of elbow joints from day 0 (38.45 ± 5.74°), day 14 (41.7 ± 6.04°), and day 28 (44.78 ± 4.69°) with statistical significance (p < 0.05) in nine elbows. Correlation analyses proved statistical significance (p < 0.05) in associations between ROM (day 0, day 14, and day 28) and IFN-γ, IL-6, IL-15, MCP-1, TNF-α, and GM-CSF concentrations (day 0, day 14, and day 28). IFN-γ, IL-6, IL-15, MCP-1, GM-CSF, and TNF- α showed negative correlation with ROM at day 0, day 14, and day 28, while IL-10 demonstrated positive correlation with ROM. As a consequence of A-MSC application to the elbow joint, we detected a statistically significant (p < 0.05) decrease in concentration levels between day 0 and day 28 for IFN-γ, IL-6, and TNF-α and statistically significant increase for IL-10. Statistical significance (p < 0.05) was detected in TNF-α, IFN-γ, and GM-CSF concentrations between day 14 and the control group as well as at day 28 and the control group. IL-6 concentrations showed statistical significance (p < 0.05) between day 14 and the control group.

Common Orthopedic Traits and Screening for Breeding Programs

Orthopedic diseases are complex traits, meaning genetics and environmental factors affect risk, making identification of genetic associations difficult. In the United States, hip and elbow scores, patellar luxation scores, Legg-Calvé-Perthes disease, and shoulder osteochondrosis affectedness are available in the Orthopedic Foundation for Animals registry. Distraction indices and extended, ventrodorsal hip conformation scores are recorded by PennHIP. Application of estimated breeding values for hip and elbow dysplasia in breeder selection reduces the severity and prevalence of these traits. Genomic prediction and whole-genome sequence technologies and methods should improve knowledge of genetics underlying orthopedic diseases, leading to improved canine orthopedic genetic quality.

Comparative evaluation of radiographic and computed tomographic findings in dogs with bilateral medial coronoid disease (MCD) presenting with unilateral forelimb lameness

OBJECTIVES

The purpose of this study was to compare the radiographic and computed tomographic (CT) findings of dogs with diagnosed bilateral medial coronoid disease, which showed clinically only unilateral lameness of the forelimbs.

MATERIALS AND METHODS

Medical records, including radiographs and CT images of dogs with diagnosed bilateral MCD showing only a unilateral forelimb lameness clinically were reviewed retrospectively. Depending on the gait of each dog we established two groups to investigate their radiographs and CT data comparatively. Group I: affected non-lame limb. Group II: affected lame limb. Several evaluation systems were used to assess which factors are important for clinical decision making and a patient tailored therapeutic plan.

RESULTS

Data from 84 affected elbow joints (42 dogs) diagnosed with MCD by computed tomography were included. Both the radiological and the CT analysis showed that there are significant differences between Groups I and II. Group I had a lower modified International Elbow Working Group Score (IEWG), the values of the Trochlear notch sclerosis were only slightly deviated, and this group showed less often a dislocation of the fragment compared to group II. Furthermore, the size of the fragment (both the median and the mean value) of the forelimbs from group II was almost twice as big as the one from group I. The following sizes of the fragments were calculated (group I versus (vs.) group II)-median: 0.09 cm2 vs. 0.16 cm2, mean value: 0.112 cm2 vs. 0.202 cm2. It could be shown that a larger fragment is more likely to dislocate than a smaller one.

CLINICAL SIGNIFICANCE

This study provides some evidence towards a better understanding of which diagnostic parameters and findings might be important in clinical decision making. Nevertheless, a "decision tree" for the correct therapy of MCD could not be determined in this study.

Effect of dog-related parameters on the flexion test outcome: A large cohort retrospective study on physiological and orthopedic pathological-related factors

Objectives

This retrospective study evaluates the dog-related factors of variation influencing the outcome of the flexion test (FT), when performed to localize pain to a joint area, on a large group of canine orthopedic patients.

Materials and methods

The selection criteria for this retrospective study were dogs undergoing a FT in a referral orthopedic clinic between 2009 and 2020 with a complete medical record. The canine FT, described in a previously published protocol, was performed on dogs presented with an orthopedic problem. In summary, a dog's joint, identified as suspected of an orthopedic problem according to the clinical examination, was flexed for 1 min before walking 15 m on a hard and even surface. The FT was considered positive if the lameness increased after the application of the FT and negative when it remained unchanged. Statistical analysis was performed to determine which of the following criteria could influence the outcome of the flexion test: age, gender, neutered status, weight category, tested joint and initial lameness score.

Results

Over 1,161 patients' files were collected and analyzed for this research. The FT showed 82.8% (95%IC: 80.5-84.9) of true positives and 17.2% of false negatives. None of the patient's intrinsic characteristics influenced the outcome of the test (age, gender, neutered status, and weight category). The orthopedic parameters, such as the initial lameness score and the tested joint, showed to have a statistically significant influence on the outcome of the test.

Clinical relevance

The FT is an easy-to-perform technique presenting reliable results on most joints. This test presents an interest when performed in addition to a complete orthopedic examination to localize pain to a joint area. Only the orthopedic pathological-related parameters such as the lameness score and the tested joint seem to influence the outcome of the FT. The FT is not influenced by the physiological-related characteristic of the patient (age, weight category, sex, and neutered status).

Across-breed genetic investigation of canine hip dysplasia, elbow dysplasia, and anterior cruciate ligament rupture using whole-genome sequencing

Here, we report the use of genome-wide association study (GWAS) for the analysis of canine whole-genome sequencing (WGS) repository data using breed phenotypes. Single-nucleotide polymorphisms (SNPs) were called from WGS data from 648 dogs that included 119 breeds from the Dog10K Genomes Project. Next, we assigned breed phenotypes for hip dysplasia (Orthopedic Foundation for Animals (OFA) HD, n = 230 dogs from 27 breeds; hospital HD, n = 279 dogs from 38 breeds), elbow dysplasia (ED, n = 230 dogs from 27 breeds), and anterior cruciate ligament rupture (ACL rupture, n = 279 dogs from 38 breeds), the three most important canine spontaneous complex orthopedic diseases. Substantial morbidity is common with these diseases. Previous within- and between-breed GWAS for HD, ED, and ACL rupture using array SNPs have identified disease-associated loci. Individual disease phenotypes are lacking in repository data. There is a critical knowledge gap regarding the optimal approach to undertake categorical GWAS without individual phenotypes. We considered four GWAS approaches: a classical linear mixed model, a haplotype-based model, a binary case-control model, and a weighted least squares model using SNP average allelic frequency. We found that categorical GWAS was able to validate HD candidate loci. Additionally, we discovered novel candidate loci and genes for all three diseases, including FBX025, IL1A, IL1B, COL27A1, SPRED2 (HD), UGDH, FAF1 (ED), TGIF2 (ED & ACL rupture), and IL22, IL26, CSMD1, LDHA, and TNS1 (ACL rupture). Therefore, categorical GWAS of ancestral dog populations may contribute to the understanding of any disease for which breed epidemiological risk data are available, including diseases for which GWAS has not been performed and candidate loci remain elusive.

The use of lateral arthroscopy portals for the management of bilateral osteochondritis dissecans of the radial head in an English bulldog

OBJECTIVE

To report a case of bilateral radial head osteochondritis dissecans (OCD) in a dog treated via lateral elbow arthroscopy portals.

STUDY DESIGN

Case report.

ANIMALS

Six month old female spayed English bulldog.

METHODS

The dog was presented for a left thoracic limb lameness localized to the elbow. Computed tomography revealed bilaterally symmetrical mineralized fragments in the lateral compartment of the elbow joint and blunting of the medial coronoid processes. The fragments were associated with a thin donation bed along the caudolateral articular surface of the radial head with moderate surrounding subchondral bone sclerosis. Bilateral elbow arthroscopy was pursued. Arthroscopy was initiated via a standard medial approach, which allowed for abrasion arthroplasty of the radial incisure and medial coronoid process but provided insufficient access to the radial head lesions. A lateral arthroscopic approach was subsequently performed and provided excellent access to the radial head for fragment retrieval and abrasion arthroplasty.

RESULTS

Histopathology of the radial head fragments revealed mild cartilage degeneration and retention of cartilaginous cores within subchondral bone, consistent with OCD. Complete resolution of lameness and elbow pain were observed on clinical examination 5 months postoperatively.

CONCLUSION

Radial head OCD can occur as a rare component of elbow dysplasia in growing dogs, and fragment retrieval with abrasion arthroplasty via lateral arthroscopic portals may be an effective treatment option.

Short term outcomes and complications of distal ulnar ostectomy in 23 juvenile dogs with carpal valgus secondary to discordant radial-ulnar physeal growth

Objective

The goal of this study was to report short term clinical and radiographic outcomes after distal ulnar ostectomy in dogs with carpal valgus due to discordant radial-ulnar growth.

Study design

Retrospective case study.

Sample group

Client owned dogs under 1 year of age with carpal valgus and open distal radial physes pre-operatively.

Methods

Medical records from four veterinary referral centers were searched from January 1, 2015 to January 1, 2022 for juvenile dogs that had been treated with distal ulnar ostectomy for carpal valgus due to premature closure of the distal ulnar physis. Patients were excluded if they were skeletally mature at the time of ostectomy; medical records were incomplete; radial physis was closed at surgery; or definitive corrective osteotomy was performed. Radiographs were evaluated pre-operatively and for short term follow up at ~8 weeks. Complications and short term clinical outcomes were evaluated also.

Results

31 limbs from 23 dogs were evaluated. Patients ranged from 4 to 10.8 months of age. All dogs presented for visible carpal valgus and varying degrees of thoracic limb lameness. Sixty-four percent of patients showed resolution of lameness while an additional 13% showed an improvement in clinical lameness without complete resolution. Complications were seen in 32% of patients with 70% percent of those being minor, bandage related complications. Radiographically, 38% of limbs showed bridging callus formation of the ostectomy at an average of 7.5 weeks post operatively and 75% percent of patients with elbow incongruity improved radiographically. There was no significant difference in radial joint angles pre-operatively and at the time of follow up.

Conclusion

Distal ulnar ostectomy ameliorates lameness in juvenile dogs with premature distal ulnar physeal closure and shows lack of progression of distal carpal valgus deformity, but does not improve joint angulation.

Clinical significance

Distal ulnar ostectomy is associated with mild bandage-related complications and halting of progressive limb deformity within the time frame evaluated, and should therefore be considered a treatment for premature closure of the distal ulnar physis. It does not lead to deformity correction at 8 weeks following surgery but is associated with improved elbow congruity.

Proximal Abduction Ulnar Osteotomy (PAUL): Short- and Long-Term Evaluation in Dogs Presenting Medial Compartment Disease

Simple Summary

Developmental elbow disease is one of the main causes of lameness in the canine species and occurs often in large and giant breed dogs. The most frequent manifestation of this pathology is known as medial compartment disease due to a physiological overload in the medial region of the elbow. It is considered as a complex disease and the treatment is focused on relieving the pain and slowing the progression of osteoarthritis. The Proximal Abduction Ulnar Osteotomy (PAUL) technique is one of the newest techniques whose purpose is the transmission of loads from the medial to the lateral compartment. In this prospective case series, the authors use the combination of elbow arthroscopy and the PAUL technique and report a significant improvement in clinical signs, showing a low major complications rate with a high degree of owner satisfaction.

Abstract

The aim of the study is to report the results obtained from performing a Proximal Abduction Ulnar Osteotomy (PAUL) technique in a cohort of dogs with medial compartment disease with short- and long-term follow-up, assessing the perception of the owners and describing the long-term complications associated with the technique. This is a clinical prospective study, including dogs diagnosed with medial compartment disease treated with elbow arthroscopy and PAUL between 2013 and 2020. Long-term follow-up data and postoperative complications were registered, and a questionnaire adapted from Fitzpatrick et al. 2009 was collected from owners. Thirty-three elbows in 26 dogs were included. The duration of follow-up ranged from 4 to 61 months (median: 24.76 months). At the end of the study, 73.1% of the owners reported excellent satisfaction and 74.1% of the owners would repeat the surgery in the same circumstances. The owner questionnaire showed a greater capacity to walk and run, without lameness and pain, and climb up and down stairs a year after surgery, being constant at the end of the study. Major postoperative complications were documented in 4/33 elbows (12.12%), including delayed union, implant failure, and osteophytosis of the medial aspect of the coronoid process. In conclusion, elbow arthroscopy and the PAUL technique achieved an evident improvement in the quality of life of patients with great satisfaction for most of the owners.

Clinical and Radiographic Evaluation of Short- and Long-Term Outcomes of Different Treatments Adopted for Elbow Medial Compartment Disease in Dogs

Medial compartment disease is a common occurrence in dogs affected by elbow dysplasia. Despite many treatments suggested in the literature, only few studies reported comparative outcomes in the short and long term. The aim of this study is to report and compare short- and long-term clinical and radiographic outcomes of dogs treated for medial compartment disease (MCD) by distal dynamic ulnar ostectomy (DUO), bi-oblique dynamic proximal ulnar osteotomy (BODPUO) and conservative management (CM). From 2016 to 2018, all medium to large dogs, aged between 5 and 12 months, affected by uni/bilateral MCD and treated by DUO, BODPUO or CM, were enrolled in this study and followed up for 24 months. Orthopedic and radiographic examinations were performed at T₀, T₂, T₁₂ and T₂₄ months after treatment. Lameness score, elbow arthralgia, elbow range of motion (ROM), osteoarthritis (OA) score and percentage of ulnar subtrochlear sclerosis (%STS) were evaluated at each time point. According to the treatment performed, dogs were divided into three groups: DUO, BODPUO and CM. Forty-five elbows from twenty-six dogs, treated with DUO (n = 17), BODPUO (n = 17) or CM (n = 11), were prospectively enrolled in the study. The patients enrolled in the CM group were older and showed more severe radiographic signs of OA, compared to those enrolled in the other two groups. Lameness and arthralgia scores (p < 10⁻⁴) were significantly decreased in patients that underwent surgical treatment and increased in patients managed conservatively (lameness p < 10⁻⁴, arthralgia p = 0.3068), at T₁₂ and T₂₄. OA score (p < 0.0040) and ROM (DUO, CM p < 10⁻⁴; BODPUO p = 0.0740) worsened in every study group, but %STS decreased in DUO (p = 0.0108), increased in the CM group (p = 0.0025) and remained unchanged in the BODPUO group (p = 0.2740). This study supports the clinical efficacy of DUO and BODPUO in reducing lameness, arthralgia and progression of %STS. Early diagnosis and surgical attention in patients affected by MCD can improve the short- and long-term outcome and reduce the progression of secondary changes.

Complications after proximal abducting ulnar osteotomy and prognostic factors in 66 dogs

Objective

To report complications and prognostic factors in dogs undergoing proximal abducting ulnar osteotomy (PAUL). To evaluate the ability to predict complications on the basis of post‐operative radiographic examination.

Study Design

Retrospective cohort study.

Animals

Sixty‐six dogs.

Methods

Medical records of dogs treated with PAUL between 2014 and 2019 were reviewed for demographics, intraoperative findings, and post‐operative complications. Post‐operative radiographs were reviewed by two masked expert orthopedic surgeons, who were asked to predict the likelihood of major mechanical complications. The prognostic value of variables was tested with univariate and multivariable logistic regression. Inter‐investigator agreement to predict complications was evaluated with two‐by‐two tables and kappa coefficient.

Results

Seventy‐four PAULs in 66 dogs were included. Duration of follow‐up ranged from 12 to 75 months (median: 53 months). Post‐operative complications were documented in 19/74 limbs (16 dogs), including major complications in 13 limbs. These complications consisted mainly of non‐union (six limbs), implant failure (two limbs), and infection (two limbs) requiring revision surgery in nine limbs. Body weight was the only variable associated with an increased risk of post‐operative complications (p = .04). Agreement between expert predictions was low (respectively k = −0.08 and k = 0.11).

Conclusion

Major complications were reported in one fourth of limbs treated with PAUL and were more likely as body weight increased. Suboptimal plate and screw placement or osteotomy reduction on post‐operative radiographs were poorly predictive of complications.

Clinical Significance

Complications are fairly common after PAUL, particularly in heavier dogs, and post‐operative radiographic examination seems unreliable to predict those.

Evaluation of post-operative complications, outcome, and long-term owner satisfaction of elbow arthrodesis (EA) in 22 dogs

The objective of this study was to report post-operative complications and outcomes in canines undergoing elbow arthrodesis (EA) with fixation techniques including bone plate fixation with a non-locking dynamic compression plate (DCP), bone plate fixation with a locking plate (LCP), and external skeletal fixator (ESF). Medical records of twenty-two cases that underwent EA between January 2009-December 2019 from 8 referral hospitals including both private practice and academic institutions were reviewed. Post-operative complications were classified as either minor or major, surgical evaluations were performed 8 weeks post operatively, and a follow-up questionnaire was sent to owners. Of the total 22 cases that met inclusion criteria, a total of 19/22 cases had complications, 12 major and 7 minor. Complications reported in 8/9, 7/9, and 4/4, for the DCP, LCP, and ESF fixation groups, respectively. Mild to moderate mechanical lameness was identified at surgical evaluation in 16/22 cases. Complete radiographic bone healing was achieved after 9 weeks in 19/22 cases. Long term owner follow up was available in 14/22 cases. Owners reported a good to normal quality of life in 13/14 cases and poor in one case. The majority of owners (11/14) reported good to excellent satisfaction with the outcome irrespective of persistent lameness. This study demonstrates that successful EA can be achieved using a variety of fixation methods, but persistent lameness is expected and complication rate is high.

Canine Elbow Dysplasia: Ununited Anconeal Process, Osteochondritis Dissecans, and Medial Coronoid Process Disease

Elbow dysplasia is a major cause of front limb lameness in medium to large dog breeds. Underlying causes include ununited anconeal process, medial coronoid process disease, and osteochondritis dissecans. When a definitive diagnosis of elbow dysplasia is made, the surgeon can improve elbow function but cannot entirely prevent progression of osteoarthrosis. Conventional surgical treatment with joint debridement and removal of loose osteocartilaginous bodies is not rewarding if joint incongruity persists; the result is overloading and subchondral bone exposure with erosion of the cartilage of the medial humeral condyle and medial coronoid area of the ulna leading to medial compartment disease.

Long-Term Prognosis of Quality of Life in Dogs Diagnosed With Mild to Moderate Elbow Dysplasia in Sweden

Objective: The objective of this study was to increase knowledge regarding long-term prognosis of mild to moderate elbow dysplasia (ED) using a canine orthopedic index.

Study Design: Cross-sectional observational study.

Sample Population: Sixty dogs randomly selected from each of five different breeds and three ED groups: ED0 (control), ED1, and ED2, based on the Kennel Club's screening results. The total number of selected dogs was 900 (60^*5^*3).

Methods: Questionnaires were administered to owners by telephone interview. Bayesian network modeling was used to assess the relation between ED grade, treatment options, dog demographics, and quality-of-life indicators.

Results: Seven hundred sixty-five questionnaires were collected (85% response rate), of which 61 concerned dogs euthanized due to osteoarthritis. There was no direct association between ED grade and owner's perceived quality of life, but ED1 and ED2 dogs were more likely to receive veterinary care and subsequent NSAID treatment compared to ED0 dogs. A significant association was found between the occurrence of euthanasia due to orthopedic disease and ED scores 1 and 2 in the sample (p < 0.001).

Conclusion: The degree of osteoarthritis was not directly associated with the canine orthopedic index, except for ED2 and lameness score. It can be speculated that owners who paid closer attention to orthopedic symptoms and perceived them as impairing their dogs' lives were also more likely to seek veterinary care and get treatment, irrespective of the ED grading.

Impact: ED1-graded dogs had a lower risk than might be expected to develop visible clinical symptoms and showed a similar quality of life as dogs with ED0. ED2-graded dogs were more likely than ED0-graded dogs to have their lives impaired by lameness, according to the owners' perception.

Staffordshire Bull Terriers in the UK: their disorder predispositions and protections

Background

The Staffordshire Bull Terrier is a popular dog breed in the UK but there is limited reliable evidence on disorder predispositions and protections within the breed. Using anonymised veterinary clinical data from the VetCompass™ Programme, this study aimed to identify common disorders with predisposition and protection in the Staffordshire Bull Terrier. The study hypothesised that Staffordshire Bull Terriers would have higher odds of aggression compared with non-Staffordshire Bull Terriers.

Results

The clinical records of a random sample of dogs of all types were reviewed to extract the most definitive diagnoses for all disorders existing during 2016. A combined list from the 30 most common disorders in Staffordshire Bull Terriers and the 30 most common disorders in non-Staffordshire Bull Terriers was generated. Multivariable logistic regression was used to report the odds of each of these disorders in 1304 (5.8%) Staffordshire Bull Terriers compared with 21,029 (94.2%) non-Staffordshire Bull Terriers. After accounting for confounding, Staffordshire Bull Terriers had significantly increased odds of 4/36 (11.1%) disorders compared to non-Staffordshire Bull Terriers with highest odds for seizure disorder (OR 2.06; 95% CI 1.24 to 3.40; p = 0.005). Conversely, Staffordshire Bull Terriers had reduced odds of 5/36 (13.9%) disorders, with lowest odds for patellar luxation (OR 0.15; 95% CI 0.04 to 0.61; p = 0.008). There was no significant difference in the odds of aggression between Staffordshire Bull Terriers compared with non-Staffordshire Bull Terriers (OR 1.09; 95% CI 0.75 to 1.58; p = 0.644).

Conclusions

This study provides a reliable evidence base of breed-specific disorder predispositions and protections that can be used by breeders to optimise breeding decisions. The findings can assist prospective owners of Staffordshire Bull Terriers to make informed decisions when acquiring a dog. From the relative number of predispositions to protections identified, there is no evidence that Staffordshire Bull Terriers have higher overall health problems than non-Staffordshire Bull Terriers.

Study of bilateral elbow joint osteoarthritis treatment using conditioned medium from allogeneic adipose tissue-derived MSCs in Labrador retrievers

Canine elbow dysplasia is a common cause of forelimb lameness in dogs and can lead to development of osteoarthritis (OA). A potential alternative to pain management is the use of a safe cell-free based therapy through trophic and paracrine factors of mesenchymal stem cells (MSCs). The aim of study was to identify the profile of selected mediators of potential clinical relevance in synovial fluid (SF) samples of dogs with elbow OA and analyse the range of motion (ROM) before and after cell-free MSCs-based treatment. In this study, conditioned medium from allogeneic canine adipose tissue - derived MSC (CM-AD-MSC) was prepared and administered into both elbow joints with OA in six Labrador retriever dogs (n = 6) on day 0 and 14 without creating a control group with a placebo. The SF of the elbow joints was analysed for the presence of several biomolecules (IL-6, IL-10, IL-8, IL-2, IL-12, TNF-αIFN-γ, MMP-3TIMP-1) before and after intraarticular applications of CM-AD-MSC. Kinematic analysis was used to assess the clinical effect of CM-AD-MSC. Analyses of SF and ROM were performed on days 0, 14 and 42. Concentration levels of MMP-3, TIMP-1, IL-6 and TNF-α in SF showed significant differences before and after the treatment (P < .05). There was a significant improvement in ROM between day 0 and 42 (P < .001). No severe adverse events were observed during the study. Results support the potential supportive effect of CM-AD-MSC as a noninvasive therapeutic tool for pain management of OA elbow joints in dogs.

Epidemiology and clinical management of elbow joint disease in dogs under primary veterinary care in the UK

Background

Conditions affecting the elbow joint are a common cause of lameness in dogs. Primary-care veterinary clinical data are now recognised as a valuable research resource. Using data from the VetCompass Programme, this study aimed to report the frequency and risk factors for elbow joint disease in dogs under primary veterinary care in the UK and describe clinical management.

Results

From 455,069 dogs under veterinary care, the one-year period prevalence for elbow joint disease diagnosis was 0.56% (95% CI: 0.53-0.60). Of 616 incident cases, the most common specific variants of elbow joint disease were osteoarthritis (n = 468, 75.97%), elbow dysplasia (190, 30.84%) and traumatic (41, 6.66%). The most common signs described by the owners were lameness (n = 466, 75.65%), difficulty exercising (123, 19.97%) and pain (86, 13.96%). The most common findings recorded on veterinary examination were pain (n = 283, 45.94%), lameness (278, 45.13%) and reduced range of movement (243, 39.45%). Common medications used included non-steroidal anti-inflammatory drugs (n = 544, 88.31%), tramadol (121, 19.64%) and disease modifying agents (118, 19.16%). Of 109 deaths involving euthanasia with information available from the 616 incident cases, elbow joint disease contributed to the decision to euthanase in 45 (41.28%) dogs.Five breeds showed increased odds of elbow joint disease compared with crossbred dogs: Rottweiler (OR: 6.16, 95% CI 3.89-9.75), Labrador Retriever (OR: 5.94, 95% CI 4.65-7.60), German Shepherd Dog (OR: 4.13, 95% CI 2.88-5.93), Golden Retriever (OR: 3.11, 95% CI 1.93-5.00) and English Springer Spaniel (OR: 2.00, 95% CI 1.26-3.18). Additional risk factors included having an adult bodyweight that was equal or higher than their breed/sex mean, advancing age, being male, being neutered, being insured and larger bodyweight.

Conclusions

Elbow joint disease is a relatively common diagnosis in dogs and has a high welfare impact as evidenced by the high proportion of cases recorded with pain, lameness and analgesic therapy. There are strong breed predispositions, in particular for large breed dogs. These findings present a clear case for improved breeding programmes to reduce the burden of elbow joint disease.

Heritability of Unilateral Elbow Dysplasia in the Dog: A Retrospective Study of Sire and Dam Influence

Canine elbow dysplasia is a significant health issue affecting many breeds. Unfortunately, treatments remain relatively limited, so control of this disease often falls to selectively breeding for dogs with normal elbows. The objectives of this study were to evaluate the heritability of left-sided vs. right-sided elbow dysplasia, and to assess potential differential sire and the dam influence on offspring elbow status. In a retrospective study, elbow data from 130,117 dogs over 2 years old representing 17 breeds were obtained from the database of the Orthopedic Foundation for Animals and included in the study. Heritability estimates for unilateral elbow dysplasia varied between breeds (ranging from 0.01 to 0.36) and were similar between the left and right elbows. The estimated genetic correlation between disease in the left and right elbow ~1 in the majority of breeds, with the exception of the hybrids, Australian Shepherds, and the Australian Cattle Dogs, likely due to low numbers of affected individuals. The sire and dam had equal impact on the offspring's elbow status. Furthermore, there was no increased risk for the sire or dam to pass on the same unilaterality of their elbow dysplasia to their offspring. However, the overall risk of elbow dysplasia in the offspring did increase when one or both parents were affected, though this also varied based on breed. Understanding of the impact that the sire and dam have on the offspring and of the overall heritability of both bilateral and unilateral elbow dysplasia is important in guiding breeding decisions to reduce the incidence in future generations of dogs.

Computed tomographic morphometry of the biceps brachii muscle tendon of dogs affected by the medial coronoid disease

The objective of this study was to measure the biceps brachii muscle (BBM) attachment to the medial coronoid process (MCP) using computed tomography images and to compare these data between clinically healthy and dogs affected by medial coronoid disease (MCD). Computed tomography was performed in MCD-affected and healthy dogs. Multiplanar reconstruction views were obtained to measure distance (cm) of the BBM attachment point to the MCP. Results showed that the mean BBM attachment point-to-MCP was 1.42 ± 0.23 cm in MCD-affected and 1.27 ± 0.20 cm in healthy dogs, respectively. In dogs with MCD, the BBM attachment point-to-MCP was significantly more abaxial than in clinically healthy dogs (p < .001). The results of this study support the hypothesis that the BBM attachment site is more abaxial to the MCP and therefore may contribute to supraphysiological overload leading to MCD. Albeit more research is necessary, this study proves a relationship between the BBM attachment point and the development of MCD.

Comparison of vertical force redistribution in the pads of dogs with elbow osteoarthritis and healthy dogs

Kinetic analyses are becoming increasingly important for biomechanical research in veterinary medicine and as a diagnostic tool for orthopaedic examinations in dogs. Such analysis enables accurate evaluation of the vertical force distribution (VFD) in canine paw pads. The aim of this study was to assess peak vertical force (PFz) as a percent of total force (%TF), vertical impulse (IFz, %TF) and time of occurrence of PFz (TPFz) as a percent of the stance phase (%SP) in the pads of all four limbs in 23 dogs with osteoarthritis in the elbow joint and 22 healthy dogs. Dogs walked over a pressure plate, and the pads were divided into four quadrants for VFD analysis. For statistical analysis, a general linear model was used to examine the difference in VFD between both groups, between fore- and hindlimbs, between body sides, and between medial/lateral and cranial/caudal quadrants. Lame dogs had lower PFz in the lame forelimb than in other limbs and transferred their weight to the caudal quadrants of the contralateral forelimb and the caudomedial quadrant of both hindlimbs. IFz was also lower in the affected forelimb and was compensated through higher loading of the caudal quadrants of the contralateral forelimb, the caudomedial quadrants of both hindlimbs and the caudolateral quadrant of the contralateral hindlimb. TPFz (%SP) occurred later in both forelimbs of the lame dogs than in those of healthy dogs. The analysis of force distribution over the paw quadrants can be used for further biomechanical studies of dogs with orthopaedic and neurological diseases.

Adaptation of the Canine Orthopaedic Index to evaluate chronic elbow osteoarthritis in Swedish dogs

BACKGROUND

Owner questionnaires may be used to assess osteoarthritis (OA) in dogs. The validated American College of Veterinary Surgeons' (ACVS) Canine Orthopaedic Index Questionnaire quantifies quality of life in dogs with orthopaedic disease. This index was modified and translated into Swedish and evaluated for validity, reliability and sensitivity. One group with confirmed moderate elbow dysplasia (n = 117) and one healthy control group (n = 146) without radiographic elbow disease and without lameness were included. Telephone interviews with the dog owners were conducted throughout the study using owner-completed questionnaires.

RESULTS

A 16-item questionnaire developed from an initial data set including 22 items, were able to differentiate between the affected group and the control group with good readability. Validity was measured through factor analysis which yielded a three-factor model accounting for 66.3% of the variance. Cronbach's α was 0.89 for the total instrument, > 0.7 for stiffness, lameness and function, but < 0.7 for quality of life. Based on the process the modified questionnaire can be used in Swedish, as the ACVS COI, to make intra-patient comparisons and evaluation of disease progression.

CONCLUSIONS

A sound owner-completed questionnaire translated into Swedish and modified, able to differ healthy dogs from dogs suffering from chronic osteoarthritis is presented. Performed statistical analysis show the items of the instrument to be reasonable and have high construct validity. The questionnaire may be used in the clinical setting and for research.

Comparison of the effect of growth factors on chondrogenesis of canine mesenchymal stem cells

Mesenchymal stem cells (MSCs) are proposed to be useful in cartilage regenerative medicine, however, canine MSCs have been reported to show poor chondrogenic capacity. Therefore, optimal conditions for chondrogenic differentiation should be determined by mimicking the developmental process. We have previously established novel and superior canine MSCs named bone marrow peri-adipocyte cells (BM-PACs) and the objective of this study was to evaluate the effects of growth factors required for in vivo chondrogenesis using canine BM-PACs. Spheroids of BM-PACs were cultured in chondrogenic medium containing 10 ng/ml transforming growth factor-β1 (TGF-β1) with or without 100 ng/ml bone morphogenetic protein-2 (BMP-2), 100 ng/ml growth differentiation factor-5 (GDF-5) or 100 ng/ml insulin-like growth factor-1 (IGF-1). Chondrogenic differentiation was evaluated by the quantification of glycosaminoglycan and Safranin O staining for proteoglycan production. The expression of cartilage matrix or hypertrophic gene/protein was also evaluated by qPCR and immunohistochemistry. Spheroids in all groups were strongly stained with Safranin O. Although BMP-2 significantly increased glycosaminoglycan production, Safranin O-negative outer layer was formed and the mRNA expression of COL10 relating to cartilage hypertrophy was also significantly upregulated (P<0.05). GDF-5 promoted the production of glycosaminoglycan and type II collagen without increasing COL10 mRNA expression. The supplementation of IGF-1 did not significantly affect cartilaginous and hypertrophic differentiation. Our results indicate that GDF-5 is a useful growth factor for the generation of articular cartilage from canine MSCs.

Synthetic osteochondral resurfacing for treatment of large caudocentral osteochondritis dissecans lesions of the humeral head in 24 dogs

OBJECTIVE

To report the outcome of dogs with large, caudocentral, osteochondritis dissecans (OCD) lesions of the humeral head treated with synthetic osteochondral resurfacing (SOR) implants.

STUDY DESIGN

Retrospective case series.

ANIMALS

Twenty-four client-owned large breed or giant dogs.

METHODS

The medical records of all dogs treated with first generation (G1) and second generation (G2) SOR implants were reviewed. All dogs were assessed with clinical examination and imaging 12 weeks after surgery. Assessment of outcome was based on subjective assessment of lameness, scoring of postoperative radiographs, and the Liverpool Osteoarthritis in Dogs (LOAD) questionnaire.

RESULTS

Osteochondral resurfacing was performed with a G1 implant in 13 dogs (15 shoulders) and a G2 implant in 11 dogs (13 shoulders). Lameness resolved in all dogs treated with G1 implants and in 10 dogs treated with G2 implants by 12 weeks after surgery. One dog treated with a G2 implant was found to have an implant-associated infection, requiring implant removal. No recurrence of lameness was reported in 9 limbs treated with G1 implants and 10 limbs treated with G2 implants that were available for clinical review at a median time of 387 and 365 days, respectively, after surgery. Mean postoperative LOAD scores were 4.2 of 52 and 5.2 of 52 in dogs treated with a G1 or a G2 implant, respectively.

CONCLUSION

Synthetic resurfacing was technically feasible in all joints of this study and resulted in good clinical results.

CLINICAL SIGNIFICANCE

The use of SOR implants seems viable to treat large caudocentral OCD lesions of the humeral head in dogs and warrants prospective comparison with conventional arthroscopic treatment.

Labrador retrievers under primary veterinary care in the UK: demography, mortality and disorders

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.

Peak forelimb ground reaction forces experienced by dogs jumping from a simulated car boot

Many dog owners allow their pets to jump out of a car boot; however, to date, there has been no study that has investigated whether this places dogs at risk of injury. The aim of this study was to investigate the relationship between height and peak vertical ground reaction force (vGRF) in static start jumps. Fifteen healthy adult dogs performed three jumps from a platform that represented common vehicle boot sill heights (0.55, 0.65, 0.75 m), landing on a single force platform. Kinetic data (mediolateral (Fx), craniocaudal (Fy) and vertical (Fz)) were normalised for body weight and analysed via a one-way repeated analysis of variance (ANOVA) and pairwise post hoc tests with a Bonferroni correction applied. There was a significant difference in peak forelimb vGRF between both the 0.55 m (27.35±4.14 N/kg) and the 0.65 m (30.84±3.66 N/kg) platform (P=0.001) and between the 0.65 and 0.75 m (34.12±3.63 N/kg) platform (P=0.001). There was no significant difference in mediolateral or craniocaudal forces between the heights examined. These results suggest that allowing dogs to jump from bigger cars with a higher boot sill may result in augmented levels of loading on anatomical structures. Further research is required to investigate the kinematic effects of height on static jump-down and how peak forelimb vGRF relates to anatomical loading and subsequent injury risk.

Ex vivo kinematic studies of a canine unlinked semi-constrained hybrid total elbow arthroplasty system

Objectives: Introduction of the Sirius® canine total elbow arthroplasty system, and presentation of the results of a passive range-of-motion analysis based on ex vivo kinematic studies pre-and post-implantation.

Materials and methods: Thoracic limbs (n = 4) of medium sized dogs were harvested by forequarter amputation. Plain orthogonal radiographs of each limb were obtained preand post-implantation. Limbs were prepared by placement of external fixator pins and Kirschner wires into the humerus and radius. Each limb was secured into a custom-made box frame and retro-reflective markers were placed on the exposed ends of the pins and wires. Each elbow was manually moved through five ranges-of-motion manoeuvres. Data collected included six trials of i) full extension to full flexion and ii) pronation and supination in 90° flexion; a three-dimensional motion capture system was used to collect and analyse the data. The Sirius elbow prosthesis was subsequently implanted and the same measurements were repeated. Data sets were tested for normality. Paired t-tests were used for comparison of pre- and post-implantation motion parameters.

Results: Kinematic analysis showed that the range-of-motion (mean and SD) for flexion and extension pre-implantation was 115° ± 6 (range: 25° to 140°). The range-of-motion in the sagittal plane post-implantation was 90° ± 4 (range: 36° to 130°) and this reduction was significant (p = 0.0001). The ranges-of-motion (mean and SD) for supination and pronation at 90° were 50° ± 5, whereas the corresponding mean ranges-of-motion post-implantation were 38° ± 6 (p = 0.0188).

Conclusion: Compared to a normal elbow, the range-of-motion was reduced. Post- implantation, supination and pronation range-of-motion was significantly reduced at 90° over pre-implantation values.

Clinical relevance: These results provide valuable information regarding the effect of the Sirius system on ex vivo kinematics of the normal canine elbow joint. Further, this particular ex vivo model allowed for satisfactory and repeatable kinematic analysis.

Analysis of risk factors for elbow dysplasia in giant breed dogs

Objective: Identify radiographic risk factors for development of elbow dysplasia in giant breed dogs less than one year of age.

Methods: Twenty-five giant breed puppies (Bernese Mountain dogs, English Mastiff, and Newfoundland) were studied. Both elbows of each dog were radiographed monthly from two to six months of age, then every other month until radial and ulnar physeal closure, followed two months later by bilateral elbow computed tomography. Radiographic parameters measured included the presence or absence of a separate centre of ossification of the anconeal process (SCOAP), medial coronoid disease (MCD), ununited anconeal process, humeral osteochondrosis, elbow incongruity, as well as the length of the radius and ulna, radius-to-ulna ratio, and date of closure of the radial and ulnar physes.

Results: Fifteen dogs completed the study. Two Bernese Mountain dogs were diagnosed with MCD. Risk factors significantly associated with medial coronoid disease included dyssynchronous physeal closure and a decreased radius-to-ulna ratio, both detected between eight to 11 months of age. A separate centre of ossification of the anconeal process was present in 60% of the dogs, and was not a risk factor for development of elbow dysplasia.

Clinical significance: Transient, dyssynchronous growth of the radius and ulna may be a risk factor for development of MCD in Bernese Mountain dogs. Dyssynchronous physeal closure or decreased radius-to-ulna ratio prior to radiographic closure of the distal ulnar and radial physes warrants further study in Bernese Mountain dogs and other breeds subject to MCD development.

Prior joint disease is associated with increased risk of periarticular histiocytic sarcoma in dogs

Periarticular histiocytic sarcoma (PAHS) is the most common synovial tumour in dogs and is characterized by aggressive local disease with a high rate of distant metastasis. Previously, an association between PAHS and prior joint disease has been demonstrated in the Bernese Mountain Dog breed and suggested in the Rottweiler. We hypothesized that this association would be present in other breeds and investigated this via a retrospective, case-controlled analysis. Cases were dogs diagnosed with PAHS of the stifle or elbow. Controls were age, breed and sex-matched dogs without a diagnosis of histiocytic sarcoma. Diagnosis of prior joint disease was determined based on review of medical records and direct veterinarian and owner communications. Data were evaluated using logistic regression, 2-sampled t tests, and chi-squared analysis. Our study population consisted of 28 cases and 46 controls, including Flat-Coated, Golden and Labrador Retrievers, Rottweilers, English Bulldogs, Shih Tzus, Australian Shepherds, Staffordshire Terriers and mixed breed dogs. Dogs with PAHS were more likely to have prior joint disease in the tumour-affected joint compared with the control population (odds ratio [OR] = 13.42, P < .0001, 95% confidence interval [CI] = 4.33-48.63). A total of 88.2% of dogs with stifle PAHS had prior joint disease in their tumour-affected joint, most commonly cranial cruciate ligament rupture. This study confirms that the previously noted association between prior joint disease and PAHS in Bernese Mountain Dogs also applies to other breeds. Additional studies are needed to further investigate for a causal relationship.

Evaluation of the Effect of Mesotherapy in the Management of Osteoarthritis-Related Pain in a Police Working Dog Using the Canine Brief Pain Inventory

CASE DESCRIPTON

A 9-year-old, 33.4kg (73.63Lb) male entire drug detection Labrador Retriever Dog was presented with an history of constant lameness from the right thoracic limb, aggravated with exercise and work.

CLINICAL FIDINGS

Clinical examination revealed mild signs of pain on the manipulation of the elbow joint, with reduced range of motion on the end feel of joint flexion and extension and crepitation. Radiographic examination of the right elbow joint revealed severe, chronic osteoarthritis, with osteophyte formation on the humeral epicondyles and articular margin of the distomedial humerus, with a narrowed joint space, and osteophytes on the proximal radius, proximomedial ulna, and anconeal process.

TREATMENT AND OUTCOME

A solution comprised of a combination of lidocaine, thiocolchicoside, and piroxicam was prepared and applied around the right elbow joint. The animal was rested for 3 days and normal work load was introduced over a 5-day period. The CPBI was completed by the trainer before treatment (T0), 14 days (T1), 1 (T2), 2 (T3), 3 (T4), 4 (T5), 5 (T6), and 6 (T7) months after treatment. Following the mesotherapy session, pain score results consistently declined until the 3-month evaluation moment. At the 6-month follow-up evaluation, values have risen to near baseline values. No side effects were recorded.

CLINICAL RELEVANCE

Mesotherapy produced significant reduction of pain score results, as measure by the CBPI, and may be a promising treatment option for canine osteoarthritis-related pain. Further studies are required.

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.

Avaliação morfológica e morfométrica da articulação umerorradioulnar em cães através de exames radiográficos e por tomografia computadorizada

RESUMO: Este estudo teve como objetivo apresentar de forma detalhada dados morfológicos e morfométricos da articulação umerorradioulnar de cães de raça definida avaliados por meio de exames físicos, radiográficos e tomográficos. A amostra dessa pesquisa constituiu-se de 44 cotovelos de cães com idades variadas. Para análise de informações obtidas, o coeficiente kappa e de correlação interclasse e associação foram realizados. Constatou-se que o desempenho individual de cada projeção radiográfica teve pobre concordância com o exame tomográfico; não houve concordância entre os observadores para as mensurações do ângulo da incisura ulnar ao exame radiográfico e tomográfico. Porém houve boa/moderada concordância para mensuração da incongruência radioulnar no plano sagital entre os observadores. Concluiu-se que nenhuma das cinco incidências radiográficas foi superior para análise radiográfica, uma vez que cada projeção apresentou melhor identificação de um compartimento do cotovelo. Medidas ao exame tomográfico para incongruência radioulnar não apresentaram reprodutibilidade no plano de reconstrução frontal, entretanto no corte sagital apresentaram boa e moderada concordância entre os observadores e que a mensuração do ângulo da incisura ulnar não apresentou repetibilidade ao exame radiográfico e nem reprodutibilidade ao exame tomográfico. Esses resultados contribuem para melhor utilização de cada exame de acordo com a região a ser avaliada bem como ressaltam a necessidade da somatória de múltiplos exames de imagem para a correta avaliação desta afecção.

COMPUTED TOMOGRAPHIC FINDINGS IN CANINE ELBOWS ARTHROSCOPICALLY DIAGNOSED WITH EROSION OF THE MEDIAL COMPARTMENT: AN ANALYTICAL METHOD COMPARISON STUDY

Medial compartment erosion is an advanced stage of medial coronoid disease, an important cause of elbow lameness in dogs, with treatment and the expected prognosis depending on the extent of the cartilage lesions. The identification of specific computed tomographic (CT) findings might facilitate the nonsurgical diagnosis and add to treatment decision making. Aims of this retrospective, analytical, method comparison study were to describe CT findings in elbows of dogs arthroscopically diagnosed with medial compartment erosion and to compare CT vs. arthroscopic findings. A total of 56 elbows met inclusion criteria. Elbows with focal (n = 13), diffuse (n = 11), and complete (n = 32) erosion were compared. Prevalence findings for CT lesions were as follows: periarticular osteophytosis (100%), abnormal shape of the medial coronoid process of the ulna (96.4%), and subchondral bone defect of the medial part of the humeral condyle (MHC; 96.4%). The three groups significantly differed for presence of medial coronoid process fragmentation, radial head subchondral bone sclerosis, and widening of the humeroulnar joint space. No significant agreement was found between CT and arthroscopy for presence of a subchondral bone defect of the MHC. A significant agreement was found between CT and arthroscopy for presence of fragmentation of the medial coronoid process. However, some of the calcified body/fragment(s) visualized on CT in the region of the medial coronoid process could not be identified via arthroscopy. Findings indicated that an accurate estimation of the extent of the elbow cartilage lesions still requires arthroscopic joint inspection.

An Update on the Pathogenesis of Osteochondrosis

Osteochondrosis is defined as a focal disturbance in endochondral ossification. The cartilage superficial to an osteochondrosis lesion can fracture, giving rise to fragments in joints known as osteochondrosis dissecans (OCD). In pigs and horses, it has been confirmed that the disturbance in ossification is the result of failure of the blood supply to epiphyseal growth cartilage and associated ischemic chondronecrosis. The earliest lesion following vascular failure is an area of ischemic chondronecrosis at an intermediate depth of the growth cartilage (osteochondrosis latens) that is detectable ex vivo, indirectly using contrast-enhanced micro- and conventional computed tomography (CT) or directly using adiabatic T1ρ magnetic resonance imaging. More chronic lesions of ischemic chondronecrosis within the ossification front (osteochondrosis manifesta) are detectable by the same techniques and have also been followed longitudinally in pigs using plain CT. The results confirm that lesions sometimes undergo spontaneous resolution, and in combination, CT and histology observations indicate that this occurs by filling of radiolucent defects with bone from separate centers of endochondral ossification that form superficial to lesions and by phagocytosis and intramembranous ossification of granulation tissue that forms deep to lesions. Research is currently aimed at discovering the cause of the vascular failure in osteochondrosis, and studies of spontaneous lesions suggest that failure is associated with the process of incorporating blood vessels into the advancing ossification front during growth. Experimental studies also show that bacteremia can lead to vascular occlusion. Future challenges are to differentiate between causes of vascular failure and to discover the nature of the heritable predisposition for osteochondrosis.

Focal humero-ulnar impingement following subtotal coronoid ostectomy in six dogs with fragmented medial coronoid process

OBJECTIVE

To report acute eburnation of joint cartilage at the humeral trochlea following subtotal coronoid ostectomy (SCO) in a clinical case series of six elbows.

MATERIAL AND METHODS

Six dogs (median BW 27.1 kg; median age 7.5 months) with fragmented medial coronoid process (FCP) and varying degree of radio-ulnar incongruence (RUI) (mean 2 mm) were treated with SCO using an arthroscopic burr. Second look arthroscopy 4-12 weeks later was performed either because of recurrent or persistent lameness in three dogs. In the others, second-look arthroscopy was scheduled prospectively because of RUI, which was thought to be a risk factor for the observed humero-ulnar impingement.

RESULTS

All six elbows had a 1-2 mm wide line of focal full-thickness cartilage loss along the edge of the SCO, while the opposing trochlea had diffuse cartilage damage of Outerbridge grade III-IV, indicating focal humero-ulnar impingement. None of the elbows showed repeated FCP.

CONCLUSION

In some cases SCO might lead to focal humero-ulnar impingement along the osteotomy line.

CLINICAL SIGNIFICANCE

Whether this relays to variations in respect the amount of resected bone (too much vs. too less) or concomitant joint pathologies like RUI or joint instability remains unknown and warrants further studies.

Topographic bone density of the radius and ulna in greyhounds and labrador retrievers with and without medial coronoid process disease

OBJECTIVE

To quantify, using computed tomography (CT), cross-sectional ulnar bone density (UBD), and regional radial bone density (RRBD) at the level of the medial coronoid process (MCP) in elbows with and without medial coronoid process disease (MCPD) and with and without fragmentation of MCP (FCP).

STUDY DESIGN

Retrospective clinical case-control and ex vivo study.

SAMPLE POPULATION

Labrador Retriever elbows (n = 54) and normal cadaveric Greyhound elbows (11) undergoing elbow CT.

MATERIALS AND METHODS

Labrador Retriever elbows were divided into 2 groups: (1) clinically unaffected and (2) MCPD-affected elbows. This 2nd group was subdivided based on the presence of a displaced FCP. UBD was measured linearly, in Hounsfield units (HU) across the widest part of the ulna incorporating the MCP. The radial head was divided into 6 zones, with mean RRBD (HU) calculated for each group.

RESULTS

MCPD-affected Labrador Retriever elbows had significantly lower UBD within the MCP with a higher UBD in the cranial ulnar medulla. Lower RRBD was also seen in the radial head adjacent to the MCP in MCPD-affected Labrador Retriever elbows with FCP compared with Labrador Retriever elbows without FCP. Greyhounds had consistently lower RRBD and UBD at the apex of the MCP compared with clinically unaffected Labrador Retriever elbows.

CONCLUSIONS

Our results suggest a caudolateral load-transfer shift through the ulna in MCPD-affected elbow joints, unloading the MCP. Changes in regional radial head bone density suggest that the radial head is involved in the pathogenesis of MCPD.

Efficacy of an oral hyaluronate and collagen supplement as a preventive treatment of elbow dysplasia

One hundred and five Labrador dogs were randomly divided into two groups to determine the number of animals that develop elbow dysplasia when treated with an oral supplement compared to untreated ones. Efficacy of the oral treatment was also evaluated once illness was diagnosed. The supplement (Hyaloral) contained hyaluronic acid, hydrolysed collagen, glucosamine, chondroitin sulphate, and gamma oryzanol. Clinical evaluation of the elbow joints was completed at months 3, 6, 12, and 20 by orthopaedic evaluations, radiography, serologic and blood analysis, and veterinarian evaluation of dysplasia symptoms. All side effects were recorded. In the control group, 33.3% of the dogs developed radiographic evidence of elbow dysplasia compared to 18.5% in the treated group. Symptoms of dysplasia at 12 months differed between the treated (12.5%) and control (61.5%) animals, and were significantly different at 20 months (p < 0.05). Differences in lameness along with movement and swelling of the elbows between groups were observed after 12 months. The treated group had improved significantly by the last visit (p < 0.05). No adverse side effects were reported. In conclusion, oral treatment with Hyaloral may have a potential cumulative action that provides protection against dysplasia and significantly improves symptoms of elbow dysplasia.