Evaluation of risk factors for degenerative joint disease associated with hip dysplasia in German Shepherd Dogs, Golden Retrievers, Labrador Retrievers, and Rottweilers

Osteoarthritis, adipokines and the translational research potential in small animal patients

Osteoartritis (OA) is a debilitating disease affecting both humans and animals. In the early stages, OA is characterized by damage to the extracellular matrix (ECM) and apoptosis and depletion of chondrocytes. OA progression is characterized by hyaline cartilage loss, chondrophyte and osteophyte formation, thickening of the joint capsule and function loss in the later stages. As the regenerative potential of cartilage is very limited and osteoarthritic changes are irreversible, prevention of OA, modulation of existing osteoarthritic joint inflammation, reducing joint pain and supporting joint function are the only options. Progression of OA and pain may necessitate surgical intervention with joint replacement or arthrodesis as end-stage procedures. In human medicine, the role of adipokines in the development and progression of OA has received increasing interest. At present, the known adipokines include leptin, adiponectin, visfatin, resistin, progranulin, chemerin, lipocalin-2, vaspin, omentin-1 and nesfatin. Adipokines have been demonstrated to play a pivotal role in joint homeostasis by modulating anabolic and catabolic balance, autophagy, apoptosis and inflammatory responses. In small animals, in terms of dogs and cats, naturally occurring OA has been clearly demonstrated as a clinical problem. Similar to humans, the etiology of OA is multifactorial and has not been fully elucidated. Humans, dogs and cats share many joint related degenerative diseases leading to OA. In this review, joint homeostasis, OA, adipokines and the most common joint diseases in small animals leading to naturally occurring OA and their relation with adipokines are discussed. The purpose of this review is highlighting the translational potential of OA and adipokines research in small animal patients.

Prevalence of osteoarthritis in the shoulder, elbow, hip and stifle joints of dogs older than 8 years

Osteoarthritis is one of the most common diseases in veterinary medicine. There are various causes for joints developing OA, with some of them being well investigated, while others are still a matter of speculation. In this retrospective study we examined the prevalence of OA in the shoulder, elbow, hip and stifle joints in a clinic population of dogs older than 8 years, which were presented mostly due to orthopaedic complaints. Dogs were included in the study if one or more of the aforementioned joints was included in the radiographs. Radiographs were reviewed by three different observers and graded by severity. Prevalence of OA was 39.2%, 57.4%, 35.9% and 36.4% for the shoulder, elbow, hip and stifle, respectively. There was no correlation between higher grades of OA and weight as well as age, but significantly higher prevalence of OA in heavier groups when grouped for weight. Sex and castration status did not affect presence of OA. As most of the examined joints were free of OA, radiographic findings suggestive of OA should not be considered normal in senescent dogs.

A missed opportunity: A scoping review of the effect of sex and age on osteoarthritis using large animal models

OBJECTIVE

The objective was to critically analyze the published literature accounting for sex differences and skeletal age (open vs. closed physis) in preclinical animal models of OA, including the disaggregation of data by sex and skeletal maturity when data is generated from combined sex and/or multi-aged cohorts without proper confounding.

METHOD

A scoping literature review of PubMed, Web of Science, EMBASE, and SCOPUS was performed for studies evaluating the effect of sex and age in experimental studies and clinical trials utilizing preclinical large animal models of OA.

RESULTS

A total of 9727 papers were identified in large animal (dog, pig, sheep, goat, horse) models for preclinical OA research, of which 238 ex vivo and/or in vivo studies disclosed model type, animal species, sex, and skeletal age sufficient to analyze their effect on outcomes. Dogs, followed by pigs, sheep, and horses, were the most commonly used models. A paucity of preclinical studies evaluated the effect of sex and age in large animal models of naturally occurring or experimentally induced OA: 26 total studies reported some kind of analysis of the effects of sex or age, with 4 studies discussing the effects of sex only, 11 studies discussing the effects of age only, and 11 studies analyzing both the effects of age and sex.

CONCLUSION

Fundamental to translational research, OARSI is uniquely positioned to develop recommendations for conducting preclinical studies using large animal models of OA that consider biological mechanisms linked to sex chromosomes, skeletal age, castration, and gonadal hormones affecting OA pathophysiology and treatment response.

Comparison of the distraction index and Norberg angle with radiographic grading of canine hip dysplasia

The Orthopedic Foundation for Animals (OFA) radiographic grading system stands as a well-established benchmark for categorizing hip dysplasia in canines. Although more objective techniques to quantify early hip laxity in young dogs, such as the Norberg angle (NA) and distraction index (DI), have been documented, there is a scarcity of published studies that directly compare these radiographic measures. The primary objectives of this prospective, analytical study were to assess and compare the NA and DI measures with OFA grades within a cohort of dogs. Thirty dogs (57 hip joints) were evaluated, with a mean age of 5.4 ± 2.9 years and a mean body weight of 34.3 ± 7.1 kg. The discriminative power of hip dysplasia for DI and NA used OFA as a reference were compared by multivariate discriminant analysis test. Using the DI (≤0.3) 12 joints were classified as normal, using NA (≥105°) 24 joints and using OFA (≤3) 29. When comparing the discriminant power of NA with OFA resulting similar (P = .8324) with correct classifications of 81% using cross validation, however, the discriminant power of dysplasia of the DI resulted significantly greater (P = .0034) than OFA with correct classifications of only 59% using cross-validation, consequently it was possible determined that of 29 patients with OFA ≤ 3, 20 had DI > 0.3. These findings demonstrated that phenotypic healthy dogs according to OFA grading can present passive hip joint laxity, as demonstrated by radiographic evaluation with distraction. Furthermore, DI can contribute to the screening of CHD when evaluated in conjunction with OFA grading.

B-mode ultrasonography and ARFI elastography of articular and peri-articular structures of the hip joint in non-dysplastic and dysplastic dogs as confirmed by radiographic examination

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 < 0.05). Measurement of the joint capsule > 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.

An update on mobility assessment of dogs with musculoskeletal disease

Mobility impairments associated with musculoskeletal diseases, such as osteoarthritis and degenerative joint disease, affect approximately 200,000 dogs annually and pose a notable challenge to canine health and welfare. Osteoarthritis causes the remodelling of synovial joints, alongside inflammation and impaired mechanical function which can be extremely debilitating. Secondary osteoarthritis commonly affects dogs and can be exacerbated by previous joint abnormalities, such as patellar luxation or cranial cruciate ligament rupture. Although musculoskeletal diseases can affect dogs of any age, the early subtle signs of gait abnormalities are perhaps missed by owners, thus, dogs may be in the latter stages of osteoarthritis progression when they are presented to veterinarians. Dogs showing subtle signs of gait abnormalities must be presented to veterinary practices for acute diagnosis to prevent long-term deterioration. Musculoskeletal diseases, such as osteoarthritis and degenerative joint disease, are commonly diagnosed via visible radiographic changes. However, veterinarians can use a combination of subjective and objective clinical scoring systems, such as clinical metrology instruments and gait assessment in conjunction with radiography to aid their diagnosis and longitudinal monitoring of musculoskeletal diseases. These scoring systems may be more sensitive to earlier signs of mobility impairments in dogs, ultimately, promoting increased canine health and welfare by enabling pain reduction, improvement of muscle strength and preservation of joint function. Current canine mobility scoring systems available to veterinarians will be discussed in turn throughout this review for implementation into clinical practice.

Predicting health outcomes in dogs using insurance claims data

In this paper we propose a machine learning-based approach to predict a multitude of insurance claim categories related to canine diseases. We introduce several machine learning approaches that are evaluated on a pet insurance dataset consisting of 785,565 dogs from the US and Canada whose insurance claims have been recorded over 17 years. 270,203 dogs with a long insurance tenure were used to train a model while the inference is applicable to all dogs in the dataset. Through this analysis we demonstrate that with this richness of data, supported by the right feature engineering, and machine learning approaches, 45 disease categories can be predicted with high accuracy.

Evaluating Disease Patterns of Military Working Dogs in the Republic of Korea: A Retrospective Study

The purpose of this study was to evaluate disease patterns among military working dogs (MWDs) at the Armed Forces Medical Research Institute (AFMRI) to provide basic medical data on Korean MWDs. The medical records of procedures performed at AFMRI between November 2017 and March 2021 were reviewed. Physical examination, diagnostic imaging, and laboratory tests were performed according to the status of each dog. A total of 353 MWDs (215 males and 138 females; mean age, 6 ± 3 years) were analyzed in this study. Among Korean MWDs, gastrointestinal (GI) disorders are the most frequently diagnosed, followed by dental and musculoskeletal disorders. Foreign body (FB) ingestion had the highest prevalence of GI disorders, with the most common FB being a leather collar or leash. General and dental surgeries, including removal of gastric FB and tooth extraction, were routinely performed at the AFMRI. Preventative care focusing on dental disease and FB ingestion may be helpful for effective performance and good quality of life in MWDs, with the regular assessment and prevention of environmental factors that may contribute to behavioral problems such as FB ingestion, coprophagy, and anorexia.

The Role of Femoral Head Size and Femoral Head Coverage in Dogs with and without Hip Dysplasia

The subject of hip dysplasia in dogs is still current and preoccupies both animal owners and veterinarians. Major factors affecting the development of the disorder are hip laxity and incongruent joints. Many studies on etiology, pathogenesis, and early diagnosis have been performed to reduce prevalence and select healthy dogs for breeding. The purpose of the present study was to investigate a possible relationship between dysplasia and femoral head area (FHA), femoral coverage by the acetabulum (CFH) and cranio-caudal distance of the dorsal acetabular rim (CrCdAR). Radiographs of a total of 264 skeletally mature dogs with similar physical characteristics (German wirehaired pointers (GWP), German shepherd dogs (GSD) and Labrador retrievers (LAB)) presented for routine hip dysplasia screening were recruited for the study. FHA, CFH and CrCdAR were measured and related to dysplasia status. Evaluations of FHA (p = 0.011), CFH (p < 0.001) and CrCdAR length (p = 0.003) measurements revealed significant interactions between breed, sex and FCI scores, so they had to be assessed separately. The results revealed that FHA tends to decrease as the hip dysplasia score worsens. There was no significant relationship between FHA and dysplasia assessment. FHA is breed-specific and is larger in normal and near-normal male (p = 0.001, p = 0.020) and female (p = 0.001, p = 0.013) GWP compared to GSD, respectively. FHA is greater in normal male GWP (p = 0.011) and GSD (p = 0.040) compared to females. There was a significant and strong positive correlation between FHA and CrCdAR in all breeds and sexes. Additionally, FCI scoring had a medium (GWP, GSD) to strong (LAB) negative correlation with CFH.

Exploration of body weight in 115 000 young adult dogs of 72 breeds

High body weight (BW), due to large size or excess body fat, has been associated with developmental and metabolic alterations, and degenerative diseases in dogs. Study objectives were to determine mean BW in young adult dogs of different breeds, including changes over a 10-year period. Body weight data from the official Swedish hip dysplasia screening program were used, including data from dogs screened at 1-2.5 years of age, in breeds with ≥ 15 individual observations/year during 2007-2016. Mean BW per breed and sex was established from 114 568 dogs representing 72 breeds. Estimates of breed BW showed significant change in 33 (45%) breeds over the 10-year period. Body weight increased in five breeds (2-14% change) and decreased in 26 breeds (1-8% change). In two breeds, BW increased in male and decreased in female dogs. This observational study provides extensive breed BW data on young adult dogs. The change in breed BW, noted in almost half of the breeds, could be due to changes either in size or in body fat mass. In certain breeds, the change in BW over time might have an impact on overall health. Studies with simultaneous evaluation of BW and body condition over time are warranted.

Radiographic Diagnosis of Hip Laxity in Rottweilers: Interobserver Agreement at Eight- and Twelve-Months of Age

Hip laxity is one of the predisposing factors of canine hip dysplasia. The early diagnosis of hip laxity allows veterinarians to prevent the participation of dysplastic dogs in breeding programs, which could lower the disease's prevalence due to its genetic background. Furthermore, it allows them to plan preventive/therapeutic procedures for mild/near-normal hips to reduce the symptoms of the disease at older ages. A reliable screening program must be repeatable and reproducible, and intra- and inter-observer studies can help us to determine the best methods. In this study, we aimed to evaluate the radiographic parameters used for the early diagnosis of hip dysplasia in Rottweilers at 8 and 12 months of age with five observers to assess the interobserver agreements. According to our findings, there were high interobserver agreements at both ages for the quantitative values, such as the center edge angle (CEA), dorsal acetabular rim slope (DARS), distraction index (DI), and Norberg angle (NA), whereas we recorded from poor to moderate agreements for the qualitative values, such as the grading of the dorsal acetabular rim (GDAR), grading of the degenerative joint disease (GDJD), location of the center of the femoral head (LCFH), and sclerosis of the cranial acetabular rim (SCAR).

Inter-Observer Agreement in Radiographic Diagnosis of Coxofemoral Joint Disease in a Closed Cohort of Four-Month-Old Rottweilers

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.

2021 AAHA Working, Assistance, and Therapy Dog Guidelines

The guidelines are the first comprehensive consensus report on veterinary healthcare recommendations for working, assistance, and therapy dogs. This category of canine patients includes a broad assortment of animals, some with well-defined functions and others that provide a more generalized support role. The guidelines discuss recommendations for dogs trained for protection, odor/scent detection, service functions for people with diagnosed disabilities or physical limitations, emotional support, and therapeutic intervention. Although the term is often used to describe dogs providing animal-assisted activities, true therapy dogs provide goal-directed therapy, often under the supervision of a healthcare professional such as an occupational therapist or psychologist. Many working dogs undergo extensive training and have rigorous physical demands placed upon them. These factors make working, assistance, and therapy dogs inherently valuable and impose a need for a high level of primary veterinary care as described in the guidelines. Because working dogs have a particularly close relationship with their handlers, a trust relationship between the practice team and the working-dog client is imperative.

Postoperative Complications of Double Pelvic Osteotomy Using Specific Plates in 305 Dogs

OBJECTIVE

 The aim of this clinical retrospective study was to describe the postoperative complications and associated factors of double pelvic osteotomy (DPO) using DPO plates.

MATERIALS AND METHODS

 Medical records were searched for dogs that underwent unilateral or bilateral DPO using DPO plates from February 2009 to October 2018 and were re-evaluated for a minimum of 1 to 2 months postoperatively. A variety of commercially available, specific DPO plates were used. Complications were determined during the immediate postoperative period and at the time of the clinical and radiographic re-evaluations done 1 and/or 2 months postoperatively.

RESULTS

 A total of 458 DPO (226 right, 232 left) performed in 305 dogs satisfied the inclusion criteria. Double pelvic osteotomy plates from eight different manufacturers were used: Fixin (n = 160), Kyon (n = 154), New Generation Device (n = 63), Hofmann (n = 61), Veterinary Instrumentation (n = 12), DePuy Synthes (n = 4), Porte (n = 3) and Koenigsee (n = 1). Mean age of the dogs was 6.2 months (range: 5-8 months), and the body weight ranged from 10 to 47 kg. Overall, a total of 42 complications occurred in 38 DPO (8.2%). Complications included greenstick fracture of the ischium in 14 DPO (3%), isolated screw loosening in 13 DPO involving 16 of a total of 2,947 screws (0.5%), isolated screw breakage in 4 DPO involving 5 of 2,947 screws (0.1%), incomplete ilium fracture in 3 DPO (0.6%), partial caudal plate avulsion in 3 DPO (0.6%), iatrogenic sciatic neuropraxia in two DPO (0.4%), suspected surgical site infection (SSI) in 1 DPO (0.2%) and persistent pain and lameness caused by the implant in 2 DPO (0.4%). The case of suspected SSI and the two cases of persistent pain were classified as major complications (3 DPO, 0.6%), requiring medical and surgical intervention, respectively, whereas other 39 complications in 35 DPO were classified as minor, not requiring treatment (7.6%).

CONCLUSION

 Double pelvic osteotomy using DPO plates appears to be a safe surgical option for the treatment of hip dysplasia in growing dogs; no catastrophic complications were reported and the incidence of complications (0.6% major complications and 7.6% minor complications) was low. This study showed that DPO using DPO plates and proper technique was safe in 92% of cases. The only two factors found to be significantly associated with the development of complications after DPO were the laterality (left-sided or right-sided) and body weight.

Factors associated with medical problems among young non-deployed U.S. military working dogs

The goals of this project were to quantify medical problems among a population of Military Working Dogs (MWDs) and analyze factors associated with common medical conditions. Medical conditions recorded in veterinary Master Problem List (MPL) entries for 774 young, non-deployed, active MWDs were categorized and combined with demographic information to analyze risk factors. Most dogs were male (74%), German Shepherd (39%) or Belgian Malinois (31%) breeds, certified in Explosive Detection (60%), and had a dark coat color (83%). Ages ranged from one to six years, with an average of 2.6 years (± 0.5 years). Eighty-three percent of dogs had a non-surgical medical problem in their record. The most common non-surgical medical problems were dermatologic (25% of MPL entries), alimentary (21%), dental (15%), soft-tissue injury (10%), and musculoskeletal conditions (4%). Factors associated with each medical condition were breed (Odds Ratios 1.96-8.24), sex and spay/neuter status (ORs 1.78-5.77), occupational duty certification (ORs 2.65-3.62), military command location (ORs 2.32-7.44), and military branch (OR 5.16). As MWDs are a valuable asset for the Department of Defense, training and work conditions for the identified at-risk groups of MWDs should be further assessed to maximize their operational capabilities and assess the potential to serve as sentinel indicators for human diseases. Improved understanding of the most common medical problems affecting MWDs, and the identification of factors associated with these conditions, can help drive changes in their preventive care.

Effectiveness of PennHIP and Orthopedic Foundation for Animals measurements of hip joint quality for breeding selection to reduce hip dysplasia in a population of purpose-bred detection dogs

OBJECTIVE

To examine the effectiveness of applying selective pressure to improve hip joint quality in purpose-bred detection dogs by use of PennHIP distraction index (DI) values along with Orthopedic Foundation for Animals (OFA) hip joint scores and to determine whether age, sex, coat color, breed, and body weight were associated with hip joint quality.

ANIMALS

615 purpose-bred detection dogs assessed for hip joint quality.

PROCEDURES

Orthopedic records of 615 purpose-bred detection dogs (569 Labrador Retrievers and 46 Labrador Retriever-German Wirehaired Pointer crossbred dogs) from 2000 through 2017 were analyzed. From 2000 to 2014, hip joint quality scores were determined by OFA evaluation only (429 dogs). Beginning in 2015, both PennHIP and OFA evaluations were used to select male and female breeding stock (179 dogs; 7 dogs were removed from analysis because they did not undergo both evaluations). Selection threshold DI value for sires and dams was ≤ 0.30; all had hip joint scores of excellent or good by OFA standards. Standard ventrodorsal hip joint-extended and stress (compression and distraction) pelvic radiographs were submitted for OFA and PennHIP evaluations.

RESULTS

Hip joint quality scores were unchanged by use of OFA measurements only. When both PennHIP and OFA measurements were used for the selection of breeding stock, hip joint quality scores improved significantly. Sex and age were significant predictors of DI values.

CONCLUSIONS AND CLINICAL RELEVANCE

PennHIP DI values were an effective measurement of hip joint quality for selecting breeding stock, and the addition of DI values to OFA measurements significantly improved hip joint quality in a population of purpose-bred dogs.

Analysis of a Laxity Index Database and Comparison with the Fédération Cynologique Internationale Grades of This Population

OBJECTIVE

 This study aimed to analyse the distribution of the laxity indices (LI) in a dog population, to compare the LI with the Fédération Cynologique Internationale (FCI) grades and to search for differences of LI between breeds.

STUDY DESIGN

 The database was composed of all dogs presented to the University Hospital of the Faculty of Veterinary Medicine in Ghent for obligatory hip screening between January 2016 and February 2019, and all patients presented to orthopaedic consultation between January 2017 and January 2019 for a complaint of hindlimb lameness, which underwent both a standard extended ventrodorsal radiograph of the hips and a stress radiograph revealing hip joint laxity. The latter was obtained by means of the Vezzoni-modified Badertscher distension device and the LI was calculated. For each dog of the population, the LI was then compared with the FCI grade.

RESULTS

 The LI values ranged between 0.15 and 1.04, with a mean of 0.46. The LI and the FCI grade increased together, and showed a moderate-to-good correlation. There was a highly significant overall difference in the mean value of LI per FCI grade group (p < 0.001). The mean LI of the Labrador Retrievers was slightly but significantly lower than the mean LI of the Golden Retrievers (p < 0.01).

CONCLUSION

 The LI calculated on a stress radiograph taken with the Vezzoni-modified Badertscher distension device shows a good correlation with the FCI grade assigned on a standard extended ventrodorsal projection. A wide range of passive hip joint laxity exists in dogs considered to be phenotypically normal based on the FCI grading method.

Working Dog Structure: Evaluation and Relationship to Function

Working dogs help to keep society and individuals safe, secure, and healthy. To perform their varied functions, it is critical to select dogs that are structurally sound and capable of demonstrating power, coordination and agility. Characteristics such as size and substance, head and axial skeletal structure, chest size and conformation, and thoracic and pelvic limb angulation should be evaluated to select the optimal combination of characteristics to suit the tasks to which each dog will be assigned. This review provides guidance on how to evaluate each of these structural components and discusses the contributions of those body parts to a working dog's function.

Evaluation of vacuum phenomenon in dogs with coxofemoral degenerative joint disease using computed tomography

Background

Degenerative joint disease (DJD) is a common orthopedic lesion in the coxofemoral joint of canine patients. Concurrent with the sign of degeneration, the vacuum phenomenon (VP), or intra-articular gas, has been observed in several locations in both human and canine patients. A cadaveric study described VP in small breed dogs without DJD but with hip laxity. However, none of the canine VP reports mentioned coxofemoral DJD. Therefore, the aim of this retrospective study was to describe the distribution of coxofemoral VP revealed on computed tomography (CT) imaging in canine patients with DJD.

Results

A total of 282 dogs (564 coxofemoral joints), comprising 142 small, 85 large, and 55 medium breeds, were included in the present study. DJD was found in 31.02% of all dogs. The incidence of DJD was highest in large breed dogs (50%), followed by medium (31.81%) and small (19.36%) breed dogs. In addition, VP was detected with CT using the pulmonary window in 31 joints of 25 dogs that received a diagnosis of hip degenerative disease. VP was found most frequently at the laterodorsal area of the acetabulum. The incidences of VP in large, small, and medium breed dogs were 35.94%, 17.14% and 8.33%, respectively. The presence of coxofemoral VP was significantly and positively correlated with DJD (odds ratio = 17.58, 95% CI 2.32–133.42).

Conclusions

The presence of coxofemoral joint DJD and VP was more likely to be detected in large breed dogs, especially in those with established DJD. CT is an advanced diagnostic imaging modality that can be used to reveal VP lesions, most of which are reported at the laterodorsal acetabulum. Further studies, including comparisons of different patient positions, may reveal more information regarding coxofemoral VP.

Canine hip dysplasia screening: Comparison of early evaluation to final grading in 231 dogs with Fédération Cynologique Internationale A and B

OBJECTIVES

This study aimed to verify if a significant difference exists between parameters in the early evaluation of normal and near-normal hip joints, to evaluate the influence of age and breed on the parameters, and to clarify the usefulness of a total score for differentiating between Fédération Cynologique Internationale (FCI) grade A and B hips.

METHODS

A total of 231 dogs were classified according to whether they had FCI A or B hips at adulthood, with measurements obtained at 14-28 weeks of age. The total score was calculated by the summation of the following quantitative parameters: angle of subluxation (AS), angle of reduction (AR), laxity index (LI), and dorsal acetabular rim slope (DARS). Logistic regression analysis was performed to establish the probability of the study population to develop an FCI B hip based on the total score. This was repeated for the highest score in combination with the worst-rated hip and once more for breeds.

RESULTS

No correlation between age and the parameters was found in the cohort, or for FCI A and B. The values of all the parameters were significantly lower in the FCI A group than in the FCI B group (AR: 4.42° ± 6.0° vs 7.62° ± 7.2°; AS: 0.45° ± 1.9° vs 1.55° ± 3.8°; LI: 0.32 ± 0.1 vs 0.36 ± 0.1; DARS: 3.30° ± 1.8° vs 3.77° ± 1.9°; TS: 11.47 ± 8.3 vs 16.65 ± 10.9). Labrador Retrievers and Golden Retrievers showed significant differences between parameters for both FCI grades. The range, where FCI A and B hips can be predicted on the basis of the total score, was different when assessed for the entire cohort, Labrador Retrievers, and Golden Retrievers.

CLINICAL SIGNIFICANCE

Our results show that even in normal and near-normal hips, the parameters significantly differed in the early evaluation. Moreover, cutoff values should be set for different breeds in the prediction of the FCI grade during early evaluation for a better breeding selection regarding canine hip dysplasia, one of the most common orthopedic diseases among large and giant breed dogs.

Radiographic findings have an association with weight bearing and locomotion in English bulldogs

Background

English bulldogs are known to be prone to skeletal problems, but knowledge is lacking of the effect of these problems on locomotion and function. This study was undertaken to report the conformational, orthopaedic and radiographic findings in a cohort of English bulldogs in Finland and to evaluate how these findings affect weight bearing and locomotion of the dogs. Twenty-eight English bulldogs were prospectively recruited to this cross-sectional study. An orthopaedic examination, measurements of conformation, static and dynamic weight bearing, and radiographic examinations of elbow, hip, stifle joints and spine were done.

Results

The English bulldogs carried a mean of 67.3% and 62.1% of their body weight in front limbs while standing and trotting, respectively. Front and hind limb lameness was seen in 20.8% (5/24) and 12.5% (3/24) of dogs, respectively. At orthopaedic examination, abnormal palpation findings (i.e. pain response, crepitation, swelling or subjectively decreased range of motion) were observed in a median of one joint (range 0–5) in each dog. Medial patellar luxation was diagnosed in 33.0% (8/24) of the evaluated dogs. At radiographic examination, elbow dysplasia was diagnosed in 48.2% (27/56) of elbow joints and severe hip dysplasia in 55.4% (31/56) of hip joints. The grade of elbow dysplasia was negatively associated with the ratio of static weight bearing between the front and hind limbs (slope estimate − 1.46, 95% CI − 2.75 to − 0.16, P = 0.03) and in dynamic weight bearing the ratio of total pressure index between the front and hind limbs (slope estimate − 0.088, 95% CI − 0.164 to 0.025, P = 0.03). The severity of hip dysplasia or hip osteoarthritis was not associated with the amount of static or dynamic weight bearing, but all except one dog were diagnosed with Fédération Cynologique Internationale grade C, D or E hips (dysplastic). In the spine, 78.6% (22/28) of the dogs had at least one malformed vertebra.

Conclusions

Orthopaedic diseases and abnormal radiographic findings were common in the English bulldogs studied. The static weight bearing of the dogs was heavily distributed to the front limbs. With increasing severity of elbow dysplasia, the static and dynamic weight bearing shifted from dysplastic elbows to hind limbs.

Risk Factors for Canine Osteoarthritis and Its Predisposing Arthropathies: A Systematic Review

Osteoarthritis is a common clinical and pathological end-point from a range of joint disorders, that ultimately lead to structural and functional decline of the joint with associated lameness and pain. Increasing understanding of the risk factors associated with osteoarthritis will assist in addressing the significant threat it poses to the welfare of the dog population and implementing preventive measures. Presented here, is the first comprehensive systematic review and evaluation of the literature reporting risk factors for canine osteoarthritis. This paper aimed to systematically collate, review and critically evaluate the published literature on risk factors for canine osteoarthritis and its predisposing conditions such as developmental joint dysplasias, cruciate ligament degeneration, and patellar luxation. Peer-reviewed publications were systematically searched for both osteoarthritis and predisposing arthropathies on Web of Science and PubMed following PRISMA (2009) guidelines, using pre-specified combinations of keywords. Sixty-two papers met the inclusion criteria and were evaluated and graded on reporting quality. Identified risk factors included both modifiable factors (neuter status and body weight) for which intervention can potentially affect the risk of occurrence of osteoarthritis, and unmodifiable factors (sex, breed, and age) which can be used to identify individuals most “at risk.” Osteoarthritis in dogs frequently develops from predisposing arthropathies, and therefore risk factors for these are also important to consider. Papers evaluated in this study were rated as medium to high-quality; gap analysis of the literature suggests there would be significant benefit from additional research into the interactions between and relative weighting of risk factors. There are a number of examples where research outcomes are conflicting such as age and sex; and further investigation into these factors would be beneficial to attain greater understanding of the nature of these risks. Comprehensively collating the published risk factors for osteoarthritis and its predisposing conditions offers opportunities to identify possible means for control and reduction within the population through preventative methods and control strategies. These factors are highlighted here, as well as current literature gaps where further research is warranted, to aid future research direction.

Assessment of the medium- to long-term radiographically confirmed outcome for juvenile dogs with hip dysplasia treated with double pelvic osteotomy

OBJECTIVE

To assess the medium- to long-term radiographically confirmed outcomes in juvenile dogs with hip dysplasia (HD) that did and did not undergo double pelvic osteotomy (DPO).

STUDY DESIGN

Retrospective case-controlled.

ANIMALS

Twenty-six dogs with HD that were candidates for DPO; 22 dogs underwent DPO (16 bilateral, six unilateral); four dogs did not.

METHODS

Initial and follow-up radiographs of DPO candidates (2011-2017) that did and did not undergo surgery were reviewed, and the British Veterinary Association and Kennel Club Hip Dysplasia Scheme score (BVA-HD), osteoarthritis score (OAS) and laxity index score (LI) were determined. Baseline and follow-up BVA-HD, OAS, and change in radiographically confirmed scores were compared by using analysis of variance for correlated samples.

RESULTS

There was no significant difference in BVA-HD or OAS between surgically treated and nonsurgically treated cohorts at baseline. Follow-up radiographs (median, 49 months) revealed that most (34/38) hips had a BVA-HD ≤10 after DPO, while four of eight hips from the nonsurgical cohort had BVA-HD >10. Follow-up BVA-HD and OAS were lower in hips after surgery (BVA-HD median 2.15, interquartile range [Q1-Q3] 1.3-4.1; OAS median 1.9, Q1-Q3 1.1-4.1) compared with the nonsurgically treated cohort (BVA-HD median 11.4, Q1-Q3 8.1-17.5, P < .01; OAS median 7.0, Q1-Q3 5.1-13.4, P < .01). Seven hips with an LI >1 had no radiographically confirmed progression of osteoarthritis after DPO.

CONCLUSION

Double pelvic osteotomy prevented radiographically confirmed progression of osteoarthritis in the medium- to long-term. Laxity index score > 1 was not a contraindication for DPO in this study.

CLINICAL SIGNIFICANCE

Double pelvic osteotomy prevents progression of radiographically confirmed features of osteoarthritis in juvenile dogs with HD.

Sexual dimorphism in limb long bones of the German Shepherd Dog

The study of sexual dimorphism in dog anatomy, especially with regard to skeletal elements, has received little attention. The present work focuses on elements of the canine stylo- and zeugopodium, less documented than the skull or pelvis in the literature. In order to identify only sex-dependent effects, we analysed a single breed: the German Shepherd Dog. Data come from 25 dogs, with a balanced sex ratio (12 males and 13 females). Four skeletal elements of the forelimb and hindlimb (humerus, radius, femur, tibia) were each measured using seven linear morphometric variables. Univariate and multivariate analyses were then performed on these 28 variables. For all measurements, males are on average larger than females, with a mean sexual dimorphism ratio of 1.07. Sexual dimorphism is significant for 92.8% of the variables. Except of femoral measurements, diaphyseal values show the highest grade of sexual dimorphism. The mean level of disparity is higher in the forelimb (1.08) than in the hindlimb (1.05). A significant dimorphism is shown for the first component of principal component analyses conducted on each skeletal element, and for the second component with humerus measurements. Discriminant functions for sex identification give success rates included between 82% for the radius and 93% for the femur, the latter providing the highest reported score for sex identification in dogs from any skeletal element. These complementary statistic methods highlight a more dimorphic forelimb in size and a more dimorphic hindlimb in shape.

Effectiveness of Canine Hip Dysplasia and Elbow Dysplasia Improvement Programs in Six UK Pedigree Breeds

Hip and elbow dysplasia are common disorders in larger dog breeds and crosses, and a known contributory factor to osteoarthritis, lameness and reduced mobility. Screening schemes evaluating the severity of hip and elbow dysplasia in the UK are administered by the British Veterinary Association (BVA) and the Kennel Club (KC). The BVA/KC Hip Dysplasia scoring scheme is over 50 years old, having originated in 1965, and has operated in its current form since 1983. The BVA/KC Elbow Dysplasia grading scheme commenced more recently in 1998 and is based on the International Elbow Working Group guidelines. Hip score and elbow grade data on a considerable number of dogs in the UK have been generated from these two screening schemes. This study analyses data from dogs of six breeds scored from 1990 to present, to establish any determinable trends in hip score and elbow grade parameters, and to examine whether the implementation of such schemes has had a positive influence on hip and elbow health. A range of criteria, including the rate of participation in the screening schemes, hip score and elbow grade parameters (e.g., median, mean, standard deviation), and estimated breeding values (EBVs) were analyzed, both in the overall population and also among breeding animals. The results show a general decline in hip score parameters (median, mean, standard deviation, and 75th percentile), revealing a reduction in the prevalence and severity of hip dysplasia. There was a more modest decline in mean elbow grade within breeds. The proportion of sires and dams (of dogs born per year) with no hip score or elbow grade fell substantially over time, demonstrating good participation in the screening schemes. In most breeds, the scores of sires and dams are demonstrably improving. There is a declining genetic trend as ascertained by EBVs for both hip scores and elbow grades in most breeds, implying that the improvement observed is due in part to selection for improvement in hip and elbow health as described by the respective screening schemes.

Genetic dissection of canine hip dysplasia phenotypes and osteoarthritis reveals three novel loci

Background

Hip dysplasia and osteoarthritis continue to be prevalent problems in veterinary and human medicine. Canine hip dysplasia is particularly problematic as it massively affects several large-sized breeds and can cause a severe impairment of the quality of life. In Finland, the complex condition is categorized to five classes from normal to severe dysplasia, but the categorization includes several sub-traits: congruity of the joint, Norberg angle, subluxation degree of the joint, shape and depth of the acetabulum, and osteoarthritis. Hip dysplasia and osteoarthritis have been proposed to have separate genetic etiologies.

Results

Using Fédération Cynologique Internationale -standardized ventrodorsal radiographs, German shepherds were rigorously phenotyped for osteoarthritis, and for joint incongruity by Norberg angle and femoral head center position in relation to dorsal acetabular edge. The affected dogs were categorized into mild, moderate and severe dysplastic phenotypes using official hip scores. Three different genome-wide significant loci were uncovered. The strongest candidate genes for hip joint incongruity were noggin (NOG), a bone and joint developmental gene on chromosome 9, and nanos C2HC-type zinc finger 1 (NANOS1), a regulator of matrix metalloproteinase 14 (MMP14) on chromosome 28. Osteoarthritis mapped to a long intergenic region on chromosome 1, between genes encoding for NADPH oxidase 3 (NOX3), an intriguing candidate for articular cartilage degradation, and AT-rich interactive domain 1B (ARID1B) that has been previously linked to joint laxity.

Conclusions

Our findings highlight the complexity of canine hip dysplasia phenotypes. In particular, the results of this study point to the potential involvement of specific and partially distinct loci and genes or pathways in the development of incongruity, mild dysplasia, moderate-to-severe dysplasia and osteoarthritis of canine hip joints. Further studies should unravel the unique and common mechanisms for the various sub-traits.

Dog as a Model for Osteoarthritis: The FGF4 Retrogene Insertion May Matter

Osteoarthritis (OA) is a degenerative joint disease associated with chronic pain and disability in humans and companion animals. The canine species can be subdivided into non-chondrodystrophic (NCD) and chondrodystrophic (CD) dogs, the latter having disproportionally short limbs due to disturbance in endochondral ossification of long bones. This phenotype is associated with retrogene insertions of the fibroblast growth factor 4 (FGF4) gene, resulting in enhanced fibroblast growth factor receptor 3 (FGFR3) signaling. The effect on cartilage is unknown and in experimental studies with dogs, breeds are seemingly employed randomly. The aim of this study was to determine whether CD- and NCD-derived cartilage differs on a structural and biochemical level, and to explore the relationship between FGF4 associated chondrodystrophy and OA. Cartilage explants from CD and NCD dogs were cultured for 21 days. Activation of canonical Wnt signaling was assessed in primary canine chondrocytes. OA and synovitis severity from an experimental OA model were compared between healthy and OA samples from CD and NCD dogs. Release of glycosaminoglycans, DNA content, and cyclooxygenase 2 (COX-2) expression were higher in NCD cartilage explants. Healthy cartilage from NCD dogs displayed higher cartilage degeneration and synovitis scores, which was aggravated by the induction of OA. Dikkopf-3 gene expression was higher in NCD cartilage. No differences in other Wnt pathway read outs were found. To conclude, chondrodystrophy associated with the FGF4 retrogene seems to render CD dogs less susceptible to the development of OA when compared with NCD dogs. These differences should be considered when choosing a canine model to study the pathobiology and new treatment strategies of OA. © 2019 The Authors. Journal of Orthopaedic Research^® Published by Wiley Periodicals, Inc. J Orthop Res 37:2550-2560, 2019.

Evaluation of visceral fat mass in dogs by computed tomography

In human medicine, computed tomography (CT) is the gold standard for visceral fat measurement. Research shows that the visceral fat area (VFA) of the umbilical slice is significantly correlated with the visceral fat volume (VFV). In veterinary medicine, however, few studies have evaluated visceral fat using CT. This study aimed to evaluate the visceral fat in dogs using CT images, and determine if the slice significantly correlated with VFV to simplify visceral fat measurements. This retrospective study includes data on 90 dogs that underwent whole-body CT scans for diagnostic purposes. VFV was calculated as the product of VFA and thickness in each CT slice; the correlation between VFV and VFA was analyzed at the level of each lumbar vertebra. Visceral fat percentage (VF%) was calculated as the ratio of the product of VFV and fat density to the body weight. Visceral fat area percentage (VFA%) was calculated as the ratio of VFA to the body area, and its correlation with the VF% and the body condition score (BCS) was analyzed. VFA was highly correlated with VFV at the level of each lumbar vertebra, with the highest correlation (r=0.964) at the L3 level. VFA% was significantly correlated with VF% (r=0.930) and weakly correlated with BCS (r=0.523). This study demonstrates that it is sufficient to use only the L3 slice for visceral fat evaluation and that the evaluation can be based on VFA% of the L3 level.

Dog owner's accuracy measuring different volumes of dry dog food using three different measuring devices

Prior research demonstrates significant inaccuracy when repeatedly measuring the same amount of dry dog food using a dry-food measuring cup, bringing into question the accuracy of measuring devices. This study aimed to determine dog owners’ accuracy when measuring different volumes of dry dog food using different types of measuring devices. One hundred dog owners, randomly assigned one of three measuring devices (a one-cup dry-food measuring cup, a two-cup graduated-liquid measuring cup or a two-cup commercial food scoop), were asked to measure ¼, ½ and 1 cup of dry dog food. Accuracy was assessed with an electronic gram scale by comparing measured volumes with the correct weight in grams. Individual accuracy ranged from −47.83% to 152.17% across devices and volumes. Measuring accuracy was found to be associated with the volume of food measured (p<0.001) and the type of measuring device used (p<0.001). Findings highlight approaches for decreasing excess intake of calories by dogs, including promotion of tactics to improve measurement accuracy (eg, gram scales, volume-calibrated dry-food measuring devices), especially for measuring small volumes.

Correlation of distraction index with arthroscopic findings in juvenile dogs with hip dysplasia

OBJECTIVE

To compare distraction index (DI) with hip arthroscopy findings in juvenile dogs with hip dysplasia undergoing unilateral or bilateral double pelvic osteotomy (DPO).

STUDY DESIGN

Retrospective case series.

ANIMALS

Twenty dogs (36 hip joints).

METHODS

Medical records from dogs undergoing unilateral or bilateral DPO (2011-2016) were reviewed. Distraction index was measured by using distraction view radiographs. Arthroscopic images were analyzed. Cartilage was graded by using the modified Outerbridge scale (0 = arthroscopically normal, 1 = chondromalacia, 2 = surface fibrillation, 3 = deep fissuring, 4 = full-thickness cartilage loss, and 5 = eburnation of exposed subchondral bone). Dorsal acetabular rim, acetabular labrum, the ligament of head of the femur, and synovitis were graded by using a four-point scale (normal, mild, moderate, severe). Spearman and Pearson correlations were used to compare DI between grade groups and age.

RESULTS

Distraction index ranged from 0.4 to 1.0 (mean 0.69 ± 0.16). Most of the hips had an arthroscopically normal femoral head and acetabulum in most regions, except for the region at the insertion of the ligament of the head of the femur. There was a low positive correlation between synovitis and DI (Spearman ρ = 0.35, P = .0346). No other differences in DI were identified between grade or age groups.

CONCLUSION

There was a low positive correlation between synovitis and DI. No other differences in DI were identified.

CLINICAL SIGNIFICANCE

Arthroscopic evaluation of the coxofemoral joint prior to DPO can allow detection of joint pathology that might not be appreciated by using traditional radiographic screening criteria.

Genetic improvement of hip-extended scores in 3 breeds of guide dogs using estimated breeding values: Notable progress but more improvement is needed

Two hip quality phenotypes-a hip-extended score assigned by a board certified radiologist and the PennHIP distraction index-were analyzed to estimate genetic parameters and to calculate estimated breeding values used for selecting replacement breeders. Radiographs obtained at 12-18 months of age were available on 5,201 German Shepherd Dogs, 4,987 Labrador Retrievers and 2,308 Golden Retrievers. Obtained by fitting a two-trait model using Bayesian techniques, estimates of heritability for the hip-extended score were 0.76, 0.72, and 0.41 in German Shepherd Dogs, Labrador Retrievers, and Golden Retrievers, respectively, while estimated heritabilities for distraction index were 0.60, 0.66 and 0.59, respectively. Genetic correlations between the two hip quality measures were -0.28 in German Shepherd Dogs, -0.21 in Labrador Retrievers, and -0.29 in Golden Retrievers. Genetic selection for improved hip quality based upon the hip extended score phenotype began in 1980. Among first generation puppies, 34% of 273 German Shepherd Dogs, 55% of 323 Labrador Retrievers, and 43% of 51 Golden Retrievers had an Excellent hip extended score. After 8 generations of selection, mostly based on estimated breeding values derived from the hip extended score, over 93% of 695 German Shepherd Dogs, 94% of 528 Labrador Retrievers, and 87% of 116 Golden Retrievers received an Excellent hip extended score. With respect to PennHIP distraction index values among these same dogs, median values were at or above 0.30 for all 3 breeds meaning that half or more of dogs possessing the Excellent hip-extended-score phenotype remained susceptible to developing the osteoarthritis of canine hip dysplasia. Genetic improvement of the hip-extended-view phenotype to its desired biological endpoint left a surprising proportion of dogs expressing sufficient joint laxity to place them in an osteoarthritis at-risk state as they age. Only by directly applying selection pressure to reduce distraction index was marked reduction in joint laxity noted.

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.

Maternal omega-3 polyunsaturated fatty acid supplementation on offspring hip joint conformation

Unsaturated omega-3 fatty acids, especially docosahexaenoic acid (DHA), when fed to dogs improves cognitive and neurological development. Supplementation with omega-3 fatty acids such as DHA and eicosapentaenoic acid (EPA) has also been associated with lipid peroxidation, which in turn has been implicated in reduced body weight and altered bone formation. To assess the impact of omega-3 fatty acid supplementation on skeletal growth, diets containing three levels of DHA and EPA (0.01 and 0.01%, 0.14 and 0.12%, and 0.21 and 0.18%, respectively) were fed to bitches during gestation and lactation with puppies also supplemented through weaning. Thus, the subjects studied were the puppies supplemented with DHA and EPA through gestation and early postnatal life. The hip joint conformation of the puppies (n = 676) was recorded at adulthood using two radiographic, non-invasive evaluations. In this population, females had higher hip distraction indices (DI) than males. Males from the lower two levels of DHA and EPA supplementation had significantly smaller hip DI than all females and males from the highest DHA and EPA supplementation. In contrast, there were no diet effects on anatomical indicators of hip joint conformation and no visible arthritic changes. These data suggest that dietary supplementation of DHA and EPA during gestation and the perinatal period to weaning does not adversely influence hip joint formation of dogs.

Demography and disorders of German Shepherd Dogs under primary veterinary care in the UK

BACKGROUND

The German Shepherd Dog (GSD) has been widely used for a variety of working roles. However, concerns for the health and welfare of the GSD have been widely aired and there is evidence that breed numbers are now in decline in the UK. Accurate demographic and disorder data could assist with breeding and clinical prioritisation. The VetCompassTM Programme collects clinical data on dogs under primary veterinary care in the UK. This study included all VetCompassTM dogs under veterinary care during 2013. Demographic, mortality and clinical diagnosis data on GSDs were extracted and reported.

RESULTS

GSDs dropped from 3.5% of the annual birth cohort in 2005 to 2.2% in 2013. The median longevity of GSDs was 10.3 years (IQR 8.0-12.1, range 0.2-17.0). The most common causes of death were musculoskeletal disorder (16.3%) and inability to stand (14.9%). The most prevalent disorders recorded were otitis externa (n = 131, 7.89, 95% CI: 6.64-9.29), osteoarthritis (92, 5.54%, 95% CI: 4.49-6.75), diarrhoea (87, 5.24%, 95% CI: 4.22-6.42), overweight/obesity (86, 5.18%, 95% CI: 4.16-6.36) and aggression (79, 4.76%, 95% CI: 3.79-5.90).

CONCLUSIONS

This study identified that GSDs have been reducing in numbers in the UK in recent years. The most frequent disorders in GSDs were otitis externa, osteoarthritis, diarrhoea, overweight/obesity and aggression, whilst the most common causes of death were musculoskeletal disorders and inability to stand. Aggression was more prevalent in males than in females. These results may assist veterinarians to offer evidence-based advice at a breed level and help to identify priorities for GSD health that can improve the breed's health and welfare.

Canine Hip Dysplasia: Diagnostic Imaging

Diagnostic imaging is the principal method used to screen for and diagnose hip dysplasia in the canine patient. Multiple techniques are available, each having advantages, disadvantages, and limitations. Hip-extended radiography is the most used method and is best used as a screening tool and for assessment for osteoarthritis. Distraction radiographic methods such as the PennHip method allow for improved detection of laxity and improved ability to predict future osteoarthritis development. More advanced techniques such as MRI, although expensive and not widely available, may improve patient screening and allow for improved assessment of cartilage health.

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.

Intra-Articular Hyaluronic Acid Compared to Traditional Conservative Treatment in Dogs with Osteoarthritis Associated with Hip Dysplasia

The purpose of this study was to compare the efficacy of the intra-articular (IA) hyaluronic acid injection to traditional conservative treatment (TCT) in dogs with osteoarthritis (OA) induced by hip dysplasia. Sixteen dogs were distributed into two groups: Hyal: IA injection of hyaluronic acid (5-10 mg), and Control: IA injection with saline solution (0.5-1.0 mL) in combination with a TCT using an oral nutraceutical (750-1000 mg every 12 h for 90 days) and carprofen (2.2 mg/kg every 12 h for 15 days). All dogs were assessed by a veterinarian on five occasions and the owner completed an assessment form (HCPI and CPBI) at the same time. The data were analyzed using unpaired t test, ANOVA, and Tukey's test (P < 0.05). Compared with baseline, lower scores were observed in both groups over the 90 days in the veterinarian evaluation, HCPI, and CPBI (P < 0.001). The Hyal group exhibited lower scores from 15 to 90 and 60 to 90 days, in the CBPI and in the veterinarian evaluation, respectively, compared to the Control group. Both treatments reduced the clinical signs associated with hip OA. However, more significant results were achieved with intra-articular hyaluronic acid injection.

Dietary supplementation with flaxseed mucilage alone or in combination with calcium in dogs: effects on apparent digestibility of fat and energy and fecal characteristics

BACKGROUND

In humans, dietary supplementation with flaxseed mucilage and calcium decrease apparent digestibility of fat and energy. These supplements could prove useful for weight management in dogs.

OBJECTIVE

To examine dry matter, energy and fat apparent digestibility, and fecal characteristics following dietary flaxseed mucilage supplementation alone or in combination with calcium.

METHODS

A single-blinded crossover feeding trial was conducted on 11 privately owned dogs. During three consecutive 14-day periods, dogs where fed commercial dog food supplemented with potato starch (control diet), flaxseed mucilage or flaxseed mucilage and calcium. Feces from the past 2 days of each period were collected for analysis. Owners recorded fecal score (1-7: 1=very hard/dry feces, 2-3=ideal and 7=diarrhea).

RESULTS

Apparent digestibility of fat was lower in both flaxseed mucilage diet (94.5±0.8%), and flaxseed mucilage and calcium diet (92.9±0.9%) compared with control diet (96.9±0.2%, P<0.0001) with fat digestibility in flaxseed mucilage and calcium diet being significantly lower than the diet supplemented with only flaxseed mucilage. Dry matter and energy digestibility was not significantly affected by diet. Fecal wet weight, dry weight and dry matter percentage was not affected by diet despite a higher fecal score for test diets (3.7±0.3) compared with control (2.8±0.2, P<0.007).

CONCLUSION

In dogs, flaxseed mucilage decreased fat apparent digestibility and this effect was enhanced when combined with calcium. Dry matter and energy apparent digestibility was not affected. Decreased fecal quality may limit the acceptable level of supplementation. Further studies on incorporating flaxseed mucilage in pet food products for weight management are needed.

Etiology and Pathogenesis of Osteochondrosis

Osteochondrosis is a common and clinically important joint disorder that occurs in human beings and in multiple animal species, most commonly pigs, horses, and dogs. This disorder is defined as a focal disturbance of enchondral ossification and is regarded as having a multifactorial etiology, with no single factor accounting for all aspects of the disease. The most commonly cited etiologic factors are heredity, rapid growth, anatomic conformation, trauma, and dietary imbalances; however, only heredity and anatomic conformation are well supported by the scientific literature. The way in which the disease is initiated has been debated. Although formation of a fragile cartilage, failure of chondrocyte differentiation, subchondral bone necrosis, and failure of blood supply to the growth cartilage all have been proposed as the initial step in the pathogenesis, the recent literature strongly supports failure of blood supply to growth cartilage as being the most likely. The term osteochondrosis has been used to describe a wide range of different lesions among different species. We suggest a refinement of this terminology to include the modifiers latens (lesion confined to epiphyseal cartilage), manifesta (lesion accompanied by delay in endochondral ossification), and dissecans (cleft formation through articular cartilage). The purpose of this review is to provide an overview of the disease, focusing on the most commonly cited theories, recent research findings, and our own views regarding the etiology and pathogenesis of osteochondrosis, in order to provide a better understanding of this apparently complex disease.

Neutering of German Shepherd Dogs: associated joint disorders, cancers and urinary incontinence

German Shepherd Dogs are important in police and military work, and are a popular family pet. The debilitating joint disorders of hip dysplasia, cranial cruciate ligament tear (CCL) and elbow dysplasia can shorten a dog's useful working life and impact its role as a family member. For this study, veterinary hospital records were examined over a 14.5-year period on 1170 intact and neutered (including spaying) German Shepherd Dogs for joint disorders and cancers previously associated with neutering. The diseases were followed through 8 years of age, with the exception of mammary cancer (MC) in females that was followed through 11 years. The cancers followed, apart from mammary, were osteosarcoma, lymphoma, hemangiosarcoma and mast cell tumour. In intact males, 7% were diagnosed with one or more joint disorders, while in males neutered prior to a year of age, a significantly higher 21% were diagnosed with one or more joint disorders. In intact females, 5% were diagnosed with one or more joint disorders, while in females neutered prior to a year of age, this measure was significantly increased to 16%. The increased joint disorder incidence mostly associated with early neutering was CCL. MC was diagnosed in 4% of intact females compared with less than 1% in females neutered before 1 year. The occurrence of the other cancers followed through 8 years of age was not higher in the neutered than in the intact dogs. Urinary incontinence, not diagnosed in intact females, was diagnosed in 7% of females neutered before 1 year, a significant difference. These findings, profiling the increase in joint disorders associated with early neutering, should help guide the timing of neutering for this breed.

Trends in popularity of some morphological traits of purebred dogs in Australia

BACKGROUND

The morphology of dogs can provide information about their predisposition to some disorders. For example, larger breeds are predisposed to hip dysplasia and many neoplastic diseases. Therefore, longitudinal trends in popularity of dog morphology can reveal potential disease pervasiveness in the future. There have been reports on the popularity of particular breeds and behavioural traits but trends in the morphological traits of preferred breeds have not been studied.

METHODS

This study investigated trends in the height, dog size and head shape (cephalic index) of Australian purebred dogs. One hundred eighty-one breeds derived from Australian National Kennel Council (ANKC) registration statistics from 1986 to 2013 were analysed. Weighted regression analyses were conducted to examine trends in the traits by using them as outcome variables, with year as the explanatory variable and numbers of registered dogs as weights. Linear regression investigated dog height and cephalic index (skull width/skull length), and multinomial logistic regression studied dog size.

RESULTS

The total number of ANKC registration had decreased gradually from 95,792 in 1986 to 66,902 in 2013. Both weighted minimal height (p = 0.014) and weighted maximal height (p < 0.001) decreased significantly over time, and the weighted cephalic index increased significantly (p < 0.001). The odds of registration of medium and small breeds increased by 5.3 % and 4.2 %, respectively, relative to large breeds (p < 0.001) and by 12.1 % and 11.0 %, respectively, relative to giant breeds (p < 0.001) for each 5-year block of time.

CONCLUSIONS

Compared to taller and larger breeds, shorter and smaller breeds have become relatively popular over time. Mean cephalic index has increased, which indicates that Australians have gradually favoured breeds with shorter and wider heads (brachycephalic). These significant trends indicate that the dog morphological traits reported here may potentially influence how people select companion dogs in Australia and provide valuable predictive information on the pervasiveness of diseases in dogs.

Derivation of mesenchymal stromal cells from canine induced pluripotent stem cells by inhibition of the TGFβ/activin signaling pathway

In this study we have generated canine mesenchymal stromal cells (MSCs), also known as mesenchymal stem cells, from canine induced pluripotent stem cells (ciPSCs) by small-molecule inhibition of the transforming growth factor beta (TGFβ)/activin signaling pathway. These ciPSC-derived MSCs (ciPSC-MSCs) express the MSC markers CD73, CD90, CD105, STRO1, cPDGFRβ and cKDR, in addition to the pluripotency factors OCT4, NANOG and REX1. ciPSC-MSCs lack immunostaining for H3K27me3, suggesting that they possess two active X chromosomes. ciPSC-MSCs are highly proliferative and undergo robust differentiation along the osteo-, chondro- and adipogenic pathways, but do not form teratoma-like tissues in vitro. Of further significance for the translational potential of ciPSC-MSCs, we show that these cells can be encapsulated and maintained within injectable hydrogel matrices that, when functionalized with bound pentosan polysulfate, dramatically enhance chondrogenesis and inhibit osteogenesis. The ability to efficiently derive large numbers of highly proliferative canine MSCs from ciPSCs that can be incorporated into injectable, functionalized hydrogels that enhance their differentiation along a desired lineage constitutes an important milestone towards developing an effective MSC-based therapy for osteoarthritis in dogs, but equally provides a model system for assessing the efficacy and safety of analogous approaches for treating human degenerative joint diseases.

Current perspectives on the optimal age to spay/castrate dogs and cats

Spaying and castrating of dogs and cats has been considered for decades to be a routine standard of practice in veterinary medicine in the US for the prevention of numerous undesirable behaviors, medical conditions, and diseases. Additionally, the procedures have been promoted as a method of curbing the severe pet-overpopulation problem in the US. Recently, however, this routine practice has come under scrutiny and become a very controversial topic. The general wisdom and safety of the procedures have been questioned by those who are concerned that the procedures may have some unintended consequences that are only recently being recognized. The purpose of this paper is to critically examine the scientific literature regarding elective spay/castration procedures and present both risks and benefits of elective gonadectomy. After the literature is examined, it becomes clear that there may not be a single absolute optimal age to spay or castrate all dogs and cats, but that the optimal age may be dependent upon several factors, including species, breed, body size, and breed-specific diseases, among others. Determining the optimal age to perform elective gonadectomy is much clearer in cats, and the literature demonstrates that the procedures can typically be safely performed at any age after 6–8 weeks of age. The optimal age to spay or castrate dogs of certain breeds (rottweiler, golden retriever, Labrador retriever, and vizsla) is becoming less clear as studies are being conducted as to the health benefits and risks in those breeds. This review will examine these controversies and make recommendations as to the optimal age to spay/castrate dogs based upon the scientific literature.