Breed susceptibility for developmental orthopedic diseases in dogs

Effects of the Direction of Two Kirschner Wires on Combined Tibial Plateau Leveling Osteotomy and Tibial Tuberosity Transposition in Miniature Breed Dogs: An Ex Vivo Study

This study evaluates the impact of Kirschner wire (K-wire) insertion direction on the biomechanical properties of combined tibial plateau leveling osteotomy (TPLO) and tibial tuberosity transposition (TTT) procedures in small-breed dogs with cranial cruciate ligament rupture and medial patella luxation. Twenty-one cadaveric tibiae were divided into two groups; the specimens were divided into two groups; one underwent TPLO-TTT with a proximal pin placement (Group TTP), and the other received TPLO-TTT with a distal pin placement (Group TTD). For both pin placements, two additional subgroups were formed: one with a 0.56 mm tension band (Groups TTP0.56 and TTD0.56) and the other with a 0.76 mm tension band (Groups TTP0.76 and TTD0.76). The tensile force was applied, and failure load and mode were recorded. The distal pin direction in Group TTD0.56 exhibited a significantly higher mean failure load (380.1 N) compared to the proximal pin direction in Group TTP0.56 (302.2 N, p = 0.028). No significant differences were observed among the other groups. This study concludes that distal pin placement can provide similar or improved mechanical stability in cases with limited space for proximal pin placement during combined TPLO and TTT procedures.

The epidemiology of osteochondrosis in an insured Swedish dog population

Osteochondrosis (OC) is a focal disturbance of endochondral ossification due to a failure of blood supply to the epiphyseal growth cartilage. In dogs, OC most commonly affects the shoulder joint, followed by the elbow, tarsal, and stifle joints. The condition is associated with clinical signs such as lameness and pain and the prognosis varies depending on the affected joint. Most epidemiologic studies of OC in dogs were performed over 20 years ago, and updated estimates of disease incidence are lacking. Therefore, the objectives of this study were to provide population-based estimates of the incidence rate, cause-specific mortality rate, and age at diagnosis of appendicular OC (AOC, including OC of the shoulder, elbow, stifle, and tarsal joints) and stifle and tarsal OC separately, using data from Agria Djurförsäkring in Sweden (2011-2016). Further, the study aimed to evaluate the risk of OC in subgroups divided by breed and sex and describe previous, concurrent, and subsequent diagnoses of the affected joint in dogs with stifle or tarsal joint OC. The study population included just over 600,000 dogs, of which 685 were affected by AOC. Stifle joint OC (n = 113) was more common than tarsal joint OC (n = 80). The incidence rate of AOC was 3.77 (95% confidence interval (CI): 3.49-4.07) cases per 10,000 dog-years at risk, while the incidence rate of stifle and joint tarsal OC was 0.64 (95% CI: 0.53-0.77) and 0.43 (95% CI: 0.34-0.54) cases per 10,000 dog-years at risk, respectively. All breeds at increased risk of AOC were large or giant, and male dogs had an increased risk of AOC compared to female dogs (RR 1.76, 95% CI: 1.50-2.07, p < 0.001). The median age at first diagnosis during the study period was 0.74 (0.32-11.5) years for AOC, 2.62 (0.45-8.82) years for stifle joint OC, and 0.73 (0.35-7.35) years for tarsal joint OC. Of the dogs with stifle or tarsal joint OC, 30.2% and 15.0% had a previous diagnosis of stifle/tarsal joint pain or other unspecific clinical signs, respectively, and 13.8% of the dogs with stifle joint OC suffered subsequent cruciate ligament rupture. Osteochondrosis was the most common reason for euthanasia in the affected dogs. In total, 77 dogs were euthanised due to AOC during the study period.

Effect of Medial Opening Wedge and External Rotational Humeral Osteotomies on Medial Elbow Compartment Pressure: An Ex Vivo Study

OBJECTIVE

 The aim of this study was to assess if the level of osteotomy (50 or 75% the length of the humerus), osteotomy angle (5, 10, or 20 degrees), direction of bone alteration (external rotational or medial opening wedge osteotomies), or orientation of osteotomy (perpendicular to the humeral long axis or perpendicular to the weight-bearing axis of the limb) affect pressure through the medial compartment of the elbow.

STUDY DESIGN

 Humeral osteotomies were performed at 50 and 75% the length of the humerus on 12 canine cadaver thoracic limbs and patient-specific three-dimensional (3D) printed plates applied to induce the desired alteration. Sensors were placed into the medial and lateral aspects of the elbow joint and the limb compressed to 90 N in a universal testing system.

RESULTS

 Increasing the angle of the induced change had a significant effect on the decreased load through the medial compartment. Performing the osteotomy at 75% of humeral length from proximal was significantly more effective at reducing the medial elbow load than performing it at 50%. Opening wedge osteotomies were more effective than external rotational osteotomies, but both were effective. Changing the direction of the osteotomy (comparing transverse to oblique) did not significantly affect the load reduction through the medial compartment.

CONCLUSION

 Performing an osteotomy at a more distal location along the humerus and increasing the angle of the induced change increased the effectiveness of load-shifting humeral osteotomies.

Assessing the Effectiveness of Modified Tibial Plateau Leveling Osteotomy Plates for Treating Cranial Cruciate Ligament Rupture and Medial Patellar Luxation in Small-Breed Dogs

In small-breed dogs with concurrent cranial cruciate ligament rupture (CCLR) and medial patellar luxation (MPL), correcting both disorders is are essential for restoring normal gait. However, the previously described surgical treatment, using two osteotomy technique, poses a high risk of fracture and instability. Addressing CCLR and MPL with a single osteotomy and implant was considered superior to the conventional method. Therefore, a pre-contoured modified tibial plateau leveling osteotomy (PCM-TPLO) plate facilitating medial shifting of the proximal tibia was developed. We compared postoperative alignment and strength between this novel plate group and a conventional tibial plateau leveling osteotomy (TPLO) plate group using eight small-breed dog cadavers each. Additionally, we investigated the potential of the novel plate as an alternative to tibial tuberosity transposition. Postoperative alignment and strength were assessed through radiographs and mechanical testing. Measurements including tibial plateau angle, mechanical medial proximal tibial angle, and number of screws within the joint were also analyzed. There were no significant differences in all measured parameters. For the novel plate, the medial displacement ratio of the proximal tibia was confirmed to be approximately 30%, and the result was thought to be appropriate. These findings suggest that the PCM-TPLO plate could be a promising alternative for treating concurrent CCLR and MPL in small-breed dogs.

Evaluation of the Tibial Plateau-Patella Angle (TPPA) in Dogs

Estimating a dog's patellar position involves various methods, which categorize it as norma, alta (high), or baja (low). However, they require various calculations. We aimed to evaluate the clinical applicability of a new method, the tibial plateau-patella angle (TPPA). This could aid in planning patella luxation surgery, estimating the patella position after TPLO and various osteotomies. We conducted a two-step study: first, on 15 stifles without pathologies from nine canine cadavers, and second, using 100 patient X-rays from the archive. Three stifle angle positions (45 ± 5°, 90 ± 5°, and 135 ± 5°) and three weight groups (S, M, and L) were evaluated in the first part of this study. Based on these results, the second part of this study was conducted using 100 pathology-free radiographs at the optimal stifle angle (90 ± 5°) from the archive. All radiographs were measured by three observers with varying levels of experience. Our results indicate that the stifle angle significantly impacted the TPPA, whereby lower values were detected with higher stifle angles, which remained consistent within the weight groups. High inter- and intra-observer agreement was achieved. The physiological TPPA values ranged from 26.7° to 48.8°, remaining consistent within the various weight groups. Observer 3 in Group S exhibited a 20% (insignificant) deviation, possibly due to challenges in determining the caudal point of the tibial plateau. In contrast with humans, TPPA values in dogs are negatively correlated with stifle angles, independent of weight. Our reliable and reproducible protocol suggests the potential benefits of training on small-breed dogs stifles.

Global trends in the research on Legg-Calve-Perthes disease in Web of Science

Background

Legg-Calve-Perthes disease (LCPD) is a form of idiopathic femoral head necrosis that can lead to permanent femoral head deformities and premature osteoarthritis in children under the age of 15. Its pathogenesis is utterly and remains to be clarified. Although many research publications on LCPD have emerged during the last few decades, few systematic bibliometric analyses of these articles have been reported.

Methods

A bibliometric analysis was performed to investigate the development processes and hotspots, as well as the collaboration and influence among countries, institutions, authors, journals, and keywords of papers relevant to LCPD from the Web of Science Core Collection (WoSCC) during the period from 1 January 2000 to 30 June 2023.

Results

A total of 2,205 researchers from 916 institutions across 53 countries/regions have contributed to 673 papers published in 199 academic journals. The research on LCPD has shown significant fluctuations but a gradual increase in the number of articles published over the last two decades. The United States leads in the number of publications of LCPD, with the Texas Scottish Rite Hospital for Children being the most productive institution. English, as the most widely used language in the world, was undoubtedly the most popular language. Herring JA, who acted as both the corresponding and first author, has contributed to the most co-cited papers published. The most number of LCPD papers are published in the Journal of Pediatric Orthopaedics, whereas the Journal of Bone and Joint Surgery American Volume garnered the highest total citations, indicating the great importance of these two journals in the field of orthopedics. The most frequently used keywords in published articles were related to the symptoms, mechanisms, and prognosis, revealing the research focus of most scholars.

Conclusion

Our research described the development trends and hotspots in the research field of LCPD and will help researchers make better decisions.

Ethical Concerns about Fashionable Dog Breeding

The historical relationship between humans and dogs has involved selective breeding for various purposes, such as hunting, guarding, and service roles. However, over time, there has been a shift in preferences from functionality to aesthetics, which has influenced the diverse sizes, shapes, and coats of dog breeds. This review looks at fashionable dog breeding and questions the ethics of prioritising looks over health and behaviour. It aims to alert potential owners, breeders, and regulators to the importance of considering a dog's overall well-being, not just its appearance, which has resulted in fad breeding, leading to genetic disorders, health issues, and a loss of biodiversity. Ethical concerns arise from breeding brachycephalic breeds with respiratory conditions, inbreeding causing inherited disorders, and overbreeding popular breeds while shelter dogs remain unadopted. Additionally, the impact of cosmetic surgeries on popular dog breeds, as well as the neglect of behavioural traits in favour of physical characteristics and strict breeding practices are also considered. The current breeding model can have a negative impact on the emotional and cognitive well-being of dogs, resulting in issues such as aggression, anxiety, and other behavioural problems that can significantly reduce their overall quality of life. Unregulated breeding practices and the demand for rare breeds can lead to illegal breeding, compromising animal welfare. Prospective owners, veterinarians, kennel clubs, and legislators all need to play a responsible role in protecting animals.

Longevity of companion dog breeds: those at risk from early death

The companion dog is one of the most phenotypically diverse species. Variability between breeds extends not only to morphology and aspects of behaviour, but also to longevity. Despite this fact, little research has been devoted to assessing variation in life expectancy between breeds or evaluating the potential for phylogenetic characterisation of longevity. Using a dataset of 584,734 unique dogs located within the UK, including 284,734 deceased, we present variation in longevity estimates within the following: parental lineage (purebred = 1 breed, crossbred ≥ 2 breeds), breed (n = 155), body size (large, medium, small), sex (male, female) and cephalic index (brachycephalic, mesocephalic, dolichocephalic). Survival estimates were then partitioned amongst phylogenetic clades: providing evidence that canine evolutionary history (via domestication and associated artificial selection) is associated with breed lifespan. This information provides evidence to inform discussions regarding pedigree health, whilst helping current/prospective owners, breeders, policy makers, funding bodies and welfare organisations improve decision making regarding canine welfare.

Determining predictive metabolomic biomarkers of meniscal injury in dogs with cranial cruciate ligament rupture

OBJECTIVES

This study used hydrogen nuclear magnetic resonance spectroscopy for the first time to examine differences in the metabolomic profile of stifle joint synovial fluid from dogs with cranial cruciate ligament rupture with and without meniscal injuries, in order to identify biomarkers of meniscal injury. Identifying a biomarker of meniscal injury could then ultimately be used to design a minimally invasive diagnostic test for meniscal injuries in dogs.

MATERIALS AND METHODS

Stifle joint synovial fluid was collected from dogs undergoing stifle joint surgery or arthrocentesis for lameness investigations. We used multi-variate statistical analysis using principal component analysis and univariate statistical analysis using one-way analysis of variance and analysis of co-variance to identify differences in the metabolomic profile between dogs with cranial cruciate ligament rupture and meniscal injury, cranial cruciate ligament rupture without meniscal injury, and neither cranial cruciate ligament rupture nor meniscal injury, taking into consideration clinical variables.

RESULTS

A total of 154 samples of canine synovial fluid were included in the study. Sixty-four metabolites were annotated to the hydrogen nuclear magnetic resonance spectroscopy spectra. Six spectral regions were found to be significantly altered (false discovery rate adjusted P-value <0.05) between groups with cranial cruciate ligament rupture with and without meniscal injury, including three attributed to nuclear magnetic resonance mobile lipids [mobile lipid -CH3 (P=0.016), mobile lipid -n(CH3 )3 (P=0.017), mobile unsaturated lipid (P=0.031)].

CLINICAL SIGNIFICANCE

We identified an increase in nuclear magnetic resonance mobile lipids in the synovial fluid of dogs with meniscal injury which are of interest as potential biomarkers of meniscal injury.

Dog size and patterns of disease history across the canine age spectrum: Results from the Dog Aging Project

Age in dogs is associated with the risk of many diseases, and canine size is a major factor in that risk. However, the size patterns are complex. While small size dogs tend to live longer, some diseases are more prevalent among small dogs. In this study we seek to quantify how the pattern of disease history varies across the spectrum of dog size, dog age, and their interaction. Utilizing owner-reported data on disease history from a substantial number of companion dogs enrolled in the Dog Aging Project, we investigate how body size, as measured by weight, associates with the lifetime prevalence of a reported condition and its pattern across age for various disease categories. We found significant positive associations between dog size and the lifetime prevalence of skin, bone/orthopedic, gastrointestinal, ear/nose/throat, cancer/tumor, brain/neurologic, endocrine, and infectious diseases. Similarly, dog size was negatively associated with lifetime prevalence of ocular, cardiac, liver/pancreas, and respiratory disease categories. Kidney/urinary disease prevalence did not vary by size. We also found that the association between age and lifetime disease prevalence varied by dog size for many conditions including ocular, cardiac, orthopedic, ear/nose/throat, and cancer. Controlling for sex, purebred vs. mixed-breed status, and geographic region made little difference in all disease categories we studied. Our results align with the reduced lifespan in larger dogs for most of the disease categories and suggest potential avenues for further examination.

The epidemiology of patellar luxation in an insured Swedish dog population

Patellar luxation (PL) is a common orthopaedic condition in dogs. This study aimed to evaluate the incidence and cause-specific mortality rate, age at diagnosis, and risk factors for medial PL (MPL), lateral PL (LPL), and bidirectional PL (BPL). Other diagnoses in dogs with PL were also explored. The study population included just over 600,000 dogs insured by Agria Pet Insurance in Sweden (2011-2016). There were 2726 dogs with PL. Medial patellar luxation affected 90 % of the dogs with PL, followed by LPL (5.9 %), BPL (2.4 %), and unspecified PL (1.6 %). The median age at first diagnosis during the study period was 2.8 years for MPL, 2.7 years for LPL, and 1.5 years for BPL. In total, 168 (6.2 %) of the dogs with PL had cruciate ligament rupture. There were substantial breed-specific differences in the risk of PL: almost all breeds at increased risk of MPL were small-sized, while several of the breeds at increased risk of LPL were large-sized. The breeds at high risk of BPL varied in size. Females had an increased risk of MPL (RR 1.2, 95 % CI: 1.1-1.3, p < 0.001) and a decreased risk of LPL (RR 0.72, 95 % CI: 0.51-1.0, p = 0.042) compared to males. In total, 116 dogs were euthanised due to PL and the breeds with the highest risk of PL-related euthanasia were the Pyrenean mountain dog, Dogue de Bordeaux, and German pinscher. The median age for PL-related euthanasia was 2.2 years.

Subchondral defects resembling osteochondrosis dissecans in joint surfaces of the extinct saber-toothed cat Smilodon fatalis and dire wolf Aenocyon dirus

Skeletal disease may hamper the behavior of large predators both living and extinct. We investigated the prevalence of osteochondrosis dissecans (OCD), a developmental bone disease affecting the joints, in two Ice Age predators: the saber-toothed cat Smilodon fatalis and dire wolf Aenocyon dirus. As published cases in modern Felidae and wild Canidae are rare, we predicted that subchondral defects resembling OCD would be rare in the extinct predators. We examined limb joints in juvenile and adult S. fatalis: 88 proximal humeri (shoulder), 834 distal femora (stifle), and 214 proximal tibiae. We also examined limb joints in juvenile and adult A. dirus: 242 proximal humeri, 266 distal femora, and 170 proximal tibiae. All specimens are from the Late Pleistocene Rancho La Brea fossil locality in Los Angeles, California, USA. While the Smilodon shoulder and tibia showed no subchondral defects, subchondral defects in the Smilodon femur had a prevalence of 6%; most defects were small (<7mm); and nine adult stifles with defects also showed osteoarthritis. Subchondral defects in the A. dirus femur had a prevalence of 2.6%; most defects were large (>12mm); and five stifles further developed mild osteoarthritis. Subchondral defects in the A. dirus shoulder had a prevalence of 4.5%; most defects were small, and three shoulders developed moderate osteoarthritis. No defects were found in the A. dirus tibia. Contrary to our prediction, we found a high prevalence of subchondral defects in the stifle and shoulder of S. fatalis and A. dirus resembling OCD found in humans and other mammals. As modern dogs affected by OCD are highly inbred, this high prevalence in the fossil taxa may suggest that they experienced inbreeding as they approached extinction. The deep-time history of this disease supports the need for monitoring of animal domestication, as well as conservation, to avoid unexpected surges in OCD under conditions like inbreeding.

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.

What Patterns in Online Classified Puppy Advertisements Can Tell Us about the Current UK Puppy Trade

The UK online puppy trade has rapidly outgrown the current legislation, aided by the anonymity provided by classified advertisement platforms. In an effort to meet increased demand, some unregulated and regulated breeders may have employed practices that negatively impact canine welfare. A paucity of up-to-date empirical data, necessary to characterise the scale and nature of this industry, makes intervention challenging. This study quantifies the online puppy trade via web-scraped online classified advertisements, providing empirical data that reveal market trends, along with spatial and temporal patterns. A total of 17,389 unique dog advertisements were collated and analysed over a 2-year period (1 June 2018 to 31 May 2020). The second year included the COVID-19 Lockdown (23 March 2020 to 31 May 2020). Statistical comparisons between dependent and independent variables were performed by linear regression. In the case of a single continuous variable, a one sample t-test was used. Of these advertisements, 57.2% were sourced from a pet-specific classified advertisement website (Pets4Homes, n = 9948), and the remaining 42.8% from two general classified advertisement websites (Gumtree, n = 7149, 41.1%; Preloved, n = 292, 1.7%, respectively). England exhibited the greatest number of advertisements (n = 10,493), followed by Wales (n = 1566), Scotland (n = 975), and Northern Ireland (NI; n = 344). Scaled for estimated human population density, Wales possessed as many advertisements per million inhabitants (489.4) as the other three combined (England = 186.4, Scotland = 177.3, and NI = 181.1). Across both years, 559 unique breeds were advertised, yet 66% of all advertisements focused on 20 breeds, and 48% advertisements focused on only 10 breeds. Regional breed popularity was suggested, with French Bulldog as the most advertised breed in England (7.3%), Scotland (6.8%), and Wales (6.8%), but Schnauzers were most popular within Northern Ireland (6.83%). Within the 559 unique breeds advertised, only 3.4% had links to conformational disorders CD); however, these breeds were among the most commonly advertised, totalling 46.9% of all ads. Across all regions, price density peaked between GBP 300 and GBP 1000, with Bulldogs presenting the greatest cost (mean = GBP 1461.38, SD = GBP 940.56), followed closely by French Bulldog (mean = GBP 1279.44, SD = GBP 664.76) and Cavapoo (mean = GBP 1064.56, SD = GBP 509.17). CD breeds were found to be GBP 208.07 more expensive, on average, than non-CD breeds. Our results represent a buoyant online market with regional and seasonal fluctuations in price, advertised breed frequency and total counts. This suggests a market influenced by consumer trends, with a particular focus on breed preference, despite links to illness/disease associated with conformation. Our findings highlight the value of utilising online classified advertisement data for long-term monitoring, in order to assist with evidence-based regulatory reform, impact measurement of targeted campaigns, and legislative enforcement.

Detection of fragment migration into the biceps tendon sheath originating from a humeral osteochondrosis lesion - A case report and review of the literature

The purpose of this report is to demonstrate that radiographic evaluation of the canine shoulder joint alone is not sensitive enough to detect migrated osteochondral fragments within the biceps tendon sheath, as a sequela to osteochondrosis dissecans of the caudal humeral head. A 6-months-old, male, 35 kg Hovawart was referred due to chronic intermittent lameness on the left forelimb. Survey radiographs revealed a semilunar radiolucency surrounded by a moderately sclerotic rim at the caudal aspect of the left humeral head, referred to as osteochondrosis dissecans. However, only computed tomography combined with ultrasonography could clearly confirm a dislodged osteochondral fragment within the left biceps tendon sheath and a consequent tenosynovitis. Arthroscopic treatment on the clinically affected left forelimb followed by an additional approach over the left biceps tendon sheath to remove the migrated fragment resulted in a complete remission of the lameness until the last follow-up one year after surgery. In our opinion, computed tomography should be applied in the medical work up of canine shoulder osteochondrosis (OC) as standard. Combined with ultrasonography, it can further aid in complete evaluation of the shoulder joint and reliable exclusion of displaced osteochondral fragments, which might also be missed during arthroscopy when located too far distally.

Refractory shock, hypercoagulability, and multiorgan thrombosis associated with hypertrophic osteodystrophy in a dog

OBJECTIVE

To describe the clinical findings and case progression in a dog presenting with severe systemic inflammatory response, refractory shock, progressive metabolic acidosis, and respiratory failure that was ultimately diagnosed with hypertrophic osteodystrophy (HOD).

CASE SUMMARY

A 4-month-old male intact Mastiff presented with a 24-hour history of lethargy and generalized ostealgia. On examination, the dog was recumbent, febrile, and tachycardic with pain on palpation of the abdomen, right femur, and mandible. Appendicular joint radiographs showed changes consistent with osteochondrosis and ulnar-retained cartilaginous cores, with no overt evidence of HOD. Initial treatment included IV fluid therapy, multimodal analgesia, and broad-spectrum antimicrobials. Vasopressor therapy was initiated following hemodynamic decompensation. Synovial fluid cytological analysis and culture revealed nonseptic suppurative inflammation and no bacterial growth, respectively. Blood and urine cultures also yielded no growth. Viscoelastic testing was consistent with hypercoagulability. The dog initially had a metabolic acidosis with appropriate respiratory compensation that progressed to a mixed metabolic and respiratory acidosis despite aggressive therapies that included antimicrobials, vasopressors, positive inotropes, and corticosteroids. Humane euthanasia was elected approximately 32 hours after admission. Necropsy yielded a diagnosis of HOD.

NEW OR UNIQUE INFORMATION PROVIDED

This is the first report detailing the occurrence of refractory shock and hypercoagulability associated with HOD in a dog without evidence of another identified comorbidity. HOD should be considered in any young, large-breed dog with generalized ostealgia and signs of systemic illness, even in the absence of classic radiographic abnormalities. Further investigation of coagulation status in dogs with HOD and a secondary systemic inflammatory response is warranted.

Preoperative and postoperative stance analysis in dogs with patellar luxation confirms lameness improvement after surgery

OBJECTIVE

To document and compare preoperative and postoperative stance analysis measurements in animals with naturally occurring patellar luxation.

ANIMALS

131 client-owned dogs surgically treated for naturally occurring unilateral or bilateral patella luxation between March 30, 2015, and February 12, 2020.

PROCEDURES

Weight bearing as a percent body weight on each limb was recorded with the use of a platform device for analyzing stance (PetSafe Stance Analyzer; LiteCure LLC, Companion Animal Health) preoperatively and postoperatively for all dogs. Signalment, limb affected, lameness grade, luxation direction, luxation grade, and surgical procedure were collected from patient records and assessed for the effects of these variables on weight bearing preoperatively or at the first or second postoperative recheck examination.

RESULTS

There were 61 males and 70 females, with a mean age and body weight of 4.62 years and 13.01 kg, included in the study. As age increased, body weight decreased in these dogs (P = .025). There was a statistically significant improvement in lameness after surgery (P = .008) at the second postoperative recheck examination. Lameness significantly decreased as postoperative time increased (P < .001, r = 0.503). As age increased, lameness at the initial visit decreased compared to younger dogs but not significantly (P = .062). There was no significant effect of preoperative luxation grade, luxation direction, surgical procedure, or sex when comparing initial lameness or lameness at recheck examination.

CLINICAL RELEVANCE

Surgical correction of patella luxation improves lameness as measured by postoperative stance analysis. Preoperative luxation grade or direction, surgical procedure performed, and sex of the animal did not significantly affect outcome in this group of dogs.

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.

Presenting signs and clinical outcome in dogs with metaphyseal osteopathy: 39 cases (2009-2018)

OBJECTIVE

To describe the presenting signs, concurrent conditions, treatment and outcome of dogs with metaphyseal osteopathy.

MATERIALS AND METHODS

Multi-centre retrospective review of medical records from January 2009 to September 2018 at four referral centres to identify dogs with a radiographic diagnosis of metaphyseal osteopathy.

RESULTS

Thirty-nine dogs were identified. The median age at onset was 14 weeks old (range, 8 to 32 weeks old). There was a higher proportion of male dogs (29 of 39 male entire, nine of 39 female entire, one of 39 female neutered and no male neutered dogs). Where information was available, median time from the most recent vaccination was 20 days (range, 2 to 144 days). The most commonly recorded clinical signs were pyrexia (34 of 39), lethargy (32 of 39), pain (30 of 39), and being non-ambulatory (17 of 39). Thirty-five dogs required hospitalisation for analgesia and supportive care, 19 of 39 were discharged on prednisolone (median dose 2.0 mg/kg/day; range, 0.9 to 2.6 mg/kg/day), 18 of 39 were discharged on non-steroidal anti-inflammatories, two of 39 did not receive NSAIDs or prednisolone at any time point. The median duration of hospitalisation for those admitted was 5 days (range, 1 to 21 days). Where follow-up was available, relapse occurred in eight of 25 cases before reaching skeletal maturity. At the time of metaphyseal osteopathy diagnosis, five of 39 cases had concurrent conditions. Where follow-up was available, four of 25 developed future immune-mediated conditions.

CLINICAL SIGNIFICANCE

Metaphyseal osteopathy should be considered in non-ambulatory painful young dogs. Some dogs developed future immune-mediated conditions, which may support the hypothesis that metaphyseal osteopathy is an autoinflammatory bone disorder. Further studies with a larger cohort are required to determine the clinical significance of this.

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.

Computed Tomographic Measurements of the Sulcus Angle of the Femoral Trochlea in Small-Breed Dogs with and without Medial Patellar Luxation

Trochleoplasty is often performed in dogs with medial patellar luxation (MPL); however, the current guidelines on when to perform a trochleoplasty in dogs are vague. The sulcus angle (SA) is used to assess the femoral trochlear morphology in humans. The aim of this study is to describe a method to measure the SA and other parameters of trochlea morphology in dogs using computed tomography. First, we searched for a suitable measuring location for the SA. Transverse images of the femurs were obtained as perpendicular planes to the tangent of the femoral trochlea which was 0 to 60 degrees (every 5 degrees) to the anatomical axis of the femur. The deepest point of the femoral trochlea was found in the transverse images perpendicular to the tangent of the femoral trochlea which was at 15 degrees to the anatomical axis of the femur. The SA and the other parameters of femoral trochlea morphology were measured at the deepest point of the femoral trochlea. The SA of the stifle joints with grade 3 and 4 MPL was significantly higher than the SA of stifle joints not affected by MPL. There was no significant difference in the SA between dogs affected by grade 1 and 2 MPL and dogs not affected by MPL. Further studies are needed to establish whether the SA can be used as selection criteria for trochleoplasty.

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.

Patellar luxation and concomitant cranial cruciate ligament rupture in dogs - A review

A patellar luxation and concomitant cranial cruciate ligament rupture is a common pathology in dogs. Diagnosis is based on clinical evidence of a patellar luxation and stifle joint instability. However, diagnostic imaging is required to assess the number of skeletal deformities and signs of instability. Surgical options include both soft tissue and osseous techniques, although, in most cases, a combination of multiple procedures is necessary to correct the patellar luxation and restore the stifle joint stability. Complication rates are generally low, but can include reluxation and implant-associated complications. This article describes the patellar luxation and cranial cruciate ligament rupture signs in dogs, including the clinical presentation and diagnosis, and discusses current treatment options.

Evaluation of Hindlimb Deformity and Posture in Dogs with Grade 2 Medial Patellar Luxation during Awake Computed Tomography Imaging while Standing

OBJECTIVE

 The aim of this study was to determine the degree of bone deformities and hindlimb postural abnormalities in a standing position in awake Toy poodles with and without grade 2 medial patellar luxation (MPL) using high speed 320-row computed tomography (CT).

METHODS

 The limbs with grade 2 MPL (MPL-G2 group) and without any orthopaedic disorders (control group) were imaged in a standing position, without sedation or anaesthesia, using CT. In MPL-G2 group, images were obtained when the patella was luxated (G2-L group) and reduced (non-luxation, G2-NL group). Bone morphologies of the femur and tibia were quantified three-dimensionally. Hindlimb standing posture was evaluated by measuring femoral rotation and abduction angles, tibial rotation angle, metatarsal rotation angle, foot rotation angle, angle between the femoral anatomical axis and the mechanical axis of hindlimb and stifle joint line convergence angle.

RESULTS

 There were no significant differences in bone morphologic parameters between the MPL-G2 group (5 limbs) and the control group (6 limbs). In the G2-NL group, there were no significant hindlimb postural abnormalities. In contrast, in the G2-L group, significant hindlimb postural abnormalities including external rotation of femur, internal rotation of tibia and foot, external rotation of tarsal joint, large stifle joint convergence angle, genu varum and toe-in standing were observed.

CONCLUSION

 Dogs with grade 2 MPL have no bone deformities but show abnormal standing posture when the patella is luxated.

[Prevention of canine parvovirosis - Part 3: Vaccine-associated adverse events]

Although nowadays vaccines, especially those against canine parvovirus (CPV), are considered to be safe, vaccine-associated adverse events (VAAEs) can occur in rare cases. Some VAAEs are mild and manifest shortly (within a few days) after vaccination (e. g. gastrointestinal signs, fever, reduced general condition, lymphadenopathy). These signs are likely a result of vaccine virus replication and indicate a good immune response. Anaphylactic reactions can also occur promptly following vaccine administration and might be life threatening. Affected dogs show clinical signs such as edema, salivation, vomiting, diarrhea, hypotension, and/or shock. Since it is often unclear which component of the vaccine carries responsibility for the anaphylactic reaction it is important to limit future vaccinations of these dogs to indispensable components only. When revaccination is unavoidable, e. g. because antibodies against CPV cannot be detected, combined vaccines should not be used and CPV (and other components, if needed) should preferably be vaccinated separately. Changing the vaccine manufacturer might also prevent further anaphylactic reactions. Finally, there are VAAEs occurring after a prolonged period of time. In dogs, it is discussed that autoimmune diseases, such as immune-mediated hemolytic anemia (IMHA), can be a consequence of excessive vaccination or in the least be triggered by vaccination. Numerous dogs with IMHA are reported to have a history of receiving a vaccination within a few weeks before the onset of clinical sings. In such dogs, further vaccinations should generally be avoided.

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.

Disorder predispositions and protections of Labrador Retrievers in the UK

The Labrador Retriever is one of the most popular dog breeds worldwide, therefore it is important to have reliable evidence on the general health issues of the breed. Using anonymised veterinary clinical data from the VetCompass Programme, this study aimed to explore the relative risk to common disorders in the Labrador Retriever. The clinical records of a random sample of dogs were reviewed to extract the most definitive diagnoses for all disorders recorded during 2016. A list of disorders was generated, including the 30 most common disorders in Labrador Retrievers and the 30 most common disorders in non-Labrador Retrievers. Multivariable logistic regression was used to report the odds of each of these disorders in 1462 (6.6%) Labrador Retrievers compared with 20,786 (93.4%) non-Labrador Retrievers. At a specific-level of diagnostic precision, after accounting for confounding, Labrador Retrievers had significantly increased odds of 12/35 (34.3%) disorders compared to non-Labrador Retrievers; osteoarthritis (OR 2.83) had the highest odds. Conversely, Labrador Retrievers had reduced odds of 7/35 (20.0%) disorders; patellar luxation (OR 0.18) had the lowest odds. This study provides useful information about breed-specific disorder predispositions and protections, which future research could evaluate further to produce definitive guidance for Labrador Retriever breeders and owners.

Proximodistal and caudocranial position of the insertion of the patellar ligament on the tibial tuberosity and patellar ligament length of normal stifles and stifles with grade II medial patellar luxation in small-breed dogs

OBJECTIVE

To assess the role of the proximodistal and caudocranial relative position of the patellar ligament insertion on the tibia and patellar ligament length-to-patellar length ratio (PLL:PL) in small-breed dogs with and without grade II medial patellar luxation (MPL).

STUDY DESIGN

Retrospective study.

SAMPLE POPULATION

Dogs weighing ≤15 kg, including 43 stifles with MPL and 34 control stifles.

METHODS

The proximodistal and caudocranial relative position of the patellar ligament insertion was determined as a ratio using the vertical (VTT) and horizontal distance (HTT) between the tibial tuberosity insertion and the tibial plateau divided by the tibial plateau length (TPL). In addition, PLL:PL and tibial plateau angle (TPA) were determined.

RESULTS

The VTT:TPL ratio was lower in affected stifles (95% CI: 0.86-0.94) than in the control group (0.93-1.01; p = .01). No other difference was identified between affected and normal stifles.

CONCLUSION

The only difference identified in this study consisted of a more proximal position of the patellar ligament insertion in the stifles of small-breed dogs with grade II MPL.

CLINICAL SIGNIFICANCE

The more proximal position of the patellar ligament insertion will result in a more proximal position of the patella in the trochlear groove and may contribute to the development of MPL. Potentially, this will also affect the risk of recurrence of MPL after surgical treatment.

Morphological Analysis of Bone Deformities of the Distal Femur in Toy Poodles with Medial Patellar Luxation

OBJECTIVE

 The aim of this study was to evaluate the bone deformities of the distal femur of Toy Poodles with medial patellar luxation (MPL) using computed tomography.

METHODS

 Computed tomography data from 37 stifles of Toy Poodles (16 normal, 10 grade 2 MPL and 11 grade 4 MPL) were analysed. For trochlear morphology, sulcus angle, medial or lateral trochlear inclination and trochlear angle were compared. For condylar morphology, distance between the apex of the medial or lateral trochlear ridge and the most caudal point of the medial or lateral femoral condyle (MC or LC), the length of the cranial/middle (anterior) part (MC(a) or LC(a')) and caudal (posterior) part (MC(p) or LC(p')) of distal femur and medial or lateral condyle width (MCW or LCW) were measured, and the ratios of medial-to-lateral condyles and anterior-posterior parts were compared.

RESULTS

 Sulcus angle was significantly higher, and medial trochlear inclination was significantly lower in grade 4 MPL group than other groups. Lateral trochlear inclination was not significantly different among 3 groups. Trochlear angles at proximal trochlear groove were significantly lower in grade 4 MPL group than other groups. MC/LC, MC(a)/LC(a'), MC(a)/MC(p), and LC(a')/LC(p') were significantly lower in grade 4 MPL group than other groups; however, there were no significant differences in MC(p)/LC(p') and MCW/LCW among three groups.

CONCLUSION

 Hypoplasia of the cranial and middle rather than caudal compartment of the distal femur was the primary morphological abnormality in Toy Poodles with grade 4 MPL.

Evaluation of functional muscle anatomy scalability in the canine hind limb

In contrast to other mammals, the large variation in dog sizes is not accompanied by any significant genetic re-organization. In order to study the relationship between body mass, limb length and the functional anatomical muscle parameters of the canine hind limb, a large dataset comprising of muscle masses, optimal muscle fibre lengths and physiological cross-sectional area's (PCSA) were acquired for twenty-five muscles in ten dogs of sizes varying between 20 kg and 52 kg. The potential of body mass and limb length for reliably scaling individual muscle masses, optimal muscle fibre lengths and PCSA's were examined. For the majority of the muscles of the canine hind limb, neither body mass nor limb length were reliable scaling parameter for either muscle masses, PCSA's and optimal fibre length. These results indicate the need of a breed-specific approach to musculoskeletal modelling in future canine musculoskeletal research.

The epidemiology of stifle joint disease in an insured Swedish dog population

BACKGROUND

Stifle joint diseases (SJD) are common in dogs and include a variety of diagnoses. The objective of the study was to provide an overview of the epidemiology of SJD in insured dogs.

METHODS

An historical single cohort study of dogs insured in Agria Pet Insurance (2011-2016) in Sweden was performed. Incidence and relative risk (RR) of SJD was calculated for the whole dog population and for subgroups divided by breed, breed group and sex.

RESULTS

The study population included almost 600,000 insured dogs (>1.7 million dog-years). Ninety-three different stifle joint diagnoses were reported in 9624 dogs, and the most common were cruciate ligament rupture and patellar luxation. The incidence of SJD was 55.4 cases per 10,000 dog-years at risk. Bulldog and boerboel had the highest RR of SJD. The breeds that accounted for the highest proportion of all SJD claimed dogs were mixed breed and Labrador retriever. Female dogs had a slightly increased RR compared with male dogs (RR 1.06, p = 0.006). The incidence increased yearly during the observation period.

CONCLUSION

The study demonstrates breed-specific differences in incidence of SJD in dogs, which may be of importance for breeders, dog owners and veterinarians.

Early Diagnosis of Canine Hip Laxity: Correlation between Clinical Orthopedic Examinations and the FCI Scoring Method in a Closed Cohort of Rottweilers

Simple Summary

Canine hip dysplasia is one of the most frequently occurring orthopedic diseases in dogs, and hip laxity is the primary sign of this disease. The early diagnosis of hip laxity in puppies would make veterinarians capable of planning preventative procedures to treat the disease or reduce the severity of disease at older ages. These procedures would improve the quality of the life of the dogs and reduce treatment costs. Furthermore, because of the importance of genetics in this disease, dogs with a risk of developing canine hip dysplasia in the future could be excluded from breeding programs. Therefore, the early diagnosis of canine hip laxity, as well as the selection of proper diagnostic methods, are of great importance in small animal orthopedics.

Abstract

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

A Modification of the Cheli Craniolateral Approach for Minimally Invasive Treatment of Osteochondritis Dissecans of the Shoulder in Dogs: Description of the Technique and Outcome in 164 Cases

OBJECTIVE

 The aim of this study was to describe a novel minimally invasive surgical approach for the treatment of shoulder osteochondritis dissecans (OCD) in dogs and to retrospectively review our clinical cases treated with this approach.

STUDY DESIGN

 The study describes a modification of Cheli surgical approach (1985), developed to reduce the degree of invasiveness as well as the incidence of postoperative complications observed in other surgical approaches to the shoulder joint. Medical records of dogs that underwent our minimally invasive approach to the scapulohumeral joint for treatment of OCD from May 2001 to May 2019 were retrospectively reviewed for intraoperative findings and complications. Clinical outcome and complications were also evaluated in the operated dogs with a minimum of a 2-month-follow-up evaluation.

RESULTS

 A total of 164 shoulders in 141 dogs (23 bilateral), 103 males and 38 females, were examined and treated with our modified craniolateral approach for the treatment of OCD of the humeral head. In all cases, the modified craniolateral approach allowed visibility and adequate exposure of the caudal humeral head surface. Radiographic and clinical follow-up evaluations were available in 123/164 (75%) cases. The clinical outcome was consistent with other reports using different surgical approaches for OCD lesions of the humeral head in dogs.

CLINICAL SIGNIFICANCE

 This technique provided a reliable approach for surgical treatment of canine shoulder OCD and can be considered a valid alternative to other surgical approaches including arthroscopy.

Biomechanical comparison of standing posture and during trot between German shepherd and Labrador retriever dogs

It is widely accepted that canine breeds stand and move differently. The prevalence of various musculoskeletal disorders such as hip and elbow dysplasia is also different between breeds. German shepherd dog (GSD) and Labrador retriever dog (LRD) are two large breeds with different conformations that have high prevalence of these disorders. This study quantifies the movement and standing posture of twelve healthy GSDs and twelve healthy LRDs to identify biomechanical similarities and differences that may be linked to sub-optimal hip and elbow mechanics. A pressure walkway and a motion capture system obtained measures of kinetics, kinematics and conformation during standing and trot. During standing, LRDs carry a greater percentage of the weight on the forelimbs (69%±5% vs. GSDs: 62%±2%, p<0.001) and their body Centre of Pressure (CoP) is located more cranially (p<0.001). GSDs had a greater pelvic tilt (79°±8 vs. 66°±9°, p = 0.004), more flexed stifles (44°±9° vs. LRDs: 34°±10°, p<0.05) and hocks (58°±11° vs. 26°±9°, p<0.01) and more extended hips (-10°±11° vs. 30°±12°, p<0.001). During trot, the GSDs’ CoP had a longer anterior-posterior trajectory (151%±22% vs. LRDs: 93%±25% of the withers height, p<0.001). Stride parameters and loading of limbs were similar when normalised to the size and weight of the dog, respectively. The LRDs had a more extended thoracolumbar angle (p<0.001) and a less flexed lumbosacral angle (p<0.05). The LRDs’ hip remained flexed during trot whereas the GSDs’ hip joint was less flexed during swing (p<0.001) and more extended in late stance and early swing (p<0.001). In conclusion, the LRDs and GSDs differ in the way they stand and move and this would result in different loading pattern of the joints. Further investigation is required to determine the extent to which biomechanical differences are linked to musculoskeletal problems presented clinically.

Comparison of growth patterns in healthy dogs and dogs in abnormal body condition using growth standards

In dogs, optimal growth is critical for future health and wellbeing. Recently, a series of evidence-based growth standards, based on bodyweight, were developed for male and female dogs across 5 different size categories. The aim of the current study was to compare growth curves depicted by the standards with patterns of growth in dogs that were either healthy, had abnormal body condition, or had various diseases with the potential to affect growth. The data came from 2 research colonies in Europe (France and UK), and a large corporate network of primary care veterinary hospitals across the USA. Age and bodyweight data were used to model growth in healthy dogs, in dogs that became overweight or underweight by 3 years of age, and in dogs with diseases associated with altered growth. Centile line crossing during the growth phase was uncommon in healthy dogs, with <5% of dogs crossing >2 centile lines. In contrast, centile line crossing was more frequent in dogs with abnormal growth patterns or abnormal body condition. Dogs that developed obesity by 3 years grew faster than the growth standards predicted, and 68% crossed ≥2 centile lines in an upwards direction. Dogs with conditions associated with accelerated growth also grew faster than expected, and 54% crossed ≥2 centile lines. In contrast dogs that became underweight by 3 years gained weight slower than expected, and 49% crossed ≥2 centile lines in a downwards direction. These results suggest that the growth standards are useful for monitoring healthy growth in dogs. Prospective studies are now required to confirm these findings and to determine whether early intervention can prevent the development of diseases.

Radiographic evaluation of patellar tendon length following corrective surgical procedures for medial patellar luxation in dogs

Objective

To quantify changes in the patellar tendon length following surgical correction of medial patellar luxation in dogs and evaluate potential risk factors associated with patellar tendon elongation.

Study design

Retrospective case series (n = 50).

Methods

Dogs that underwent surgery for medial patellar luxation correction and had 2–3 months follow up were included. Digital radiographs were utilized to quantify the patellar tendon length to patellar length ratio at various follow-up points. Odds ratio comparisons between potential risk factors associated with changes in patellar tendon length were performed.

Results

Post-operative patellar tendon lengthening of ≥ 5% was observed in 20% of stifles and post-operative patellar tendon shortening of ≥ 5% was observed in 22% of stifles at the 2–3 month follow up period. The risk factors including age, body weight, trochleoplasty and grade of medial patellar luxation were not significantly associated with risk of patellar tendon elongation. Patellar tendon lengthening was not associated with recurrence of luxation.

Conclusion

Patellar tendon lengthening and shortening can be observed in dogs following common medial patellar luxation corrective procedures in the short term follow up period. Patellar tendon lengthening does not appear to be associated with age, weight, trochleoplasty, grade of luxation, or risk of luxation recurrence.

Neurologic and magnetic resonance imaging features of German Shepherd Dogs with cervical spondylomyelopathy: 10 cases (2006-2018)

OBJECTIVE

To describe the neurologic signs and MRI findings for German Shepherd Dogs (GSDs) with cervical spondylomyelopathy (CSM).

ANIMALS

10 GSDs with confirmed CSM.

PROCEDURES

Medical records from January 2006 through July 2018 were reviewed to identify dogs with CSM. For each CSM-affected dog, information regarding age, duration of clinical signs, presence of neurologic signs, and treatments administered were obtained; the main site and cause of spinal cord compression and other vertebral and spinal cord changes were identified on MRI images.

RESULTS

Data for 9 male and 1 female (mean age, 6.2 years) GSDs with CSM were assessed. Dogs were classified as having chronic (n = 9) or acute (1) CSM. Nine dogs had ataxia; 1 dog had only signs of cervical hyperesthesia. Neurologic examination findings localized the lesion to the cervical portion of the vertebral column in each dog. The main spinal cord compression site was at the C6-7 (n = 5), C5-6 (4), or C4-5 (1) intervertebral spaces; osseous proliferation of the articular processes was the sole or a contributory cause of these compressions for 6 of the 10 dogs. Eight dogs also had dorsal compression of the spinal cord as the result of ligamenta flava hypertrophy.

CONCLUSIONS AND CLINICAL RELEVANCE

The 10 GSDs of the present retrospective case series had CSM that was often characterized by osseous changes and a ligamentous component and were older than dogs of other breeds (eg, Great Dane and Mastiff) with osseous-associated CSM described in previous reports. Cervical spondylomyelopathy should be a differential diagnosis for GSDs with ataxia, paresis, or signs of cervical hyperesthesia.

Effect of Limb Position on Measurements of the Quadriceps Muscle Length/Femoral Length Ratio in Normal Beagle Dogs

OBJECTIVES

 Dogs with patella alta reportedly have a shorter extensor mechanism than normal dogs. The present study aimed to measure the length of the extensor mechanism and to assess the effect of limb position on the quadriceps muscle length (QML)/femoral bone length (FL) ratio.

STUDY DESIGN

 Three-dimensional computed tomography images were taken of 12 Beagle dogs. Each dog underwent computed tomographic imaging 24 times with different limb positions. The QML/FL was measured on each image, along with the hip flexion-extension, hip abduction-adduction and stifle flexion-extension angles. Multiple regression analysis was used to determine the effect of these angles on the QML/FL.

RESULTS

 The QML/FL was increased with the hip extended (standardized partial regression coefficient 0.855 with linear plotting, 0.829 with log plotting) and with the stifle flexed (standardized partial regression coefficient 0.814 with linear plotting, 0.800 with log plotting). The partial regression coefficient of the hip abduction-adduction angle was small, indicating a small impact on the QML/FL. The 95% confidence range of the QML/FL with the hip extended and stifle flexed was 0.87 to 1.00 (mean ± standard deviation: 0.93 ± 0.03).

CONCLUSION

 The QML/FL was more influenced by joint angles when the hip was flexed or the stifle was extended. Hence, these positions should be avoided when evaluating the QML/FL so that the QML is less altered by slight positioning disparities.

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.

Spontaneous dog osteoarthritis - a One Medicine vision

Osteoarthritis (OA) is a global disease that, despite extensive research, has limited treatment options. Pet dogs share both an environment and lifestyle attributes with their owners, and a growing awareness is developing in the public and among researchers that One Medicine, the mutual co-study of animals and humans, could be beneficial for both humans and dogs. To that end, this Review highlights research opportunities afforded by studying dogs with spontaneous OA, with a view to sharing this active area of veterinary research with new audiences. Similarities and differences between dog and human OA are examined, and the proposition is made that suitably aligned studies of spontaneous OA in dogs and humans, in particular hip and knee OA, could highlight new avenues of discovery. Developing cross-species collaborations will provide a wealth of research material and knowledge that is relevant to human OA and that cannot currently be obtained from rodent models or experimentally induced dog models of OA. Ultimately, this Review aims to raise awareness of spontaneous dog OA and to stimulate discussion regarding its exploration under the One Medicine initiative to improve the health and well-being of both species.

Osteoarthritis occurs spontaneously in pet dogs, which often share environmental and lifestyle risk-factors with their owners. This Review aims to stimulate cooperation between medical and veterinary research under the One Medicine initiative to improve the welfare of dogs and humans.

Dogs have many analogous spontaneous diseases that result in end-stage osteoarthritis (OA).

Inbreeding and the predisposition of certain dog breeds for OA enable easier identification of candidate genetic associations than in outbred humans.

Dog OA subtypes offer a potential stratification rationale for aetiological differences and alignment to analogous human OA phenotypes.

The relatively compressed time course of spontaneous dog OA offers longitudinal research opportunities.

Collaboration with veterinary researchers can provide tissue samples from early-stage OA and opportunities to evaluate new therapeutics in a spontaneous disease model.

Awareness of the limitations and benefits of using clinical veterinary patients in research is important.

Demography and commonly recorded clinical conditions of Chihuahuas under primary veterinary care in the UK in 2016

BACKGROUND

The Chihuahua, the world's smallest dog breed, is a popular breed in the UK today. The VetCompass™ Programme collates de-identified clinical records from primary-care veterinary practices in the UK for epidemiological research. This study aimed to characterise the demography, age at death and common disorders of Chihuahuas under primary veterinary care during 2016 in the UK.

RESULTS

Chihuahuas comprised 11,647/336,865 (3.46%) dogs under veterinary care during 2016. The annual proportional birth rate for Chihuahuas rose from 1.01% in 2005 to 5.35% in 2016. Median adult bodyweight was 3.4 kg (interquartile range [IQR]: 2.7-4.3, range 0.8-9.8).). Median age was 2.8 years (interquartile range [IQR] 1.6-4.9). Median age at death from this young expanding population was 8.2 years (IQR 3.5-12.1). Females (10.2 years) outlived males (6.9 years) (Mann-Whitney U test: P = 0.005). The most common grouped causes of death were heart disease (18.8%, 95% CI: 10.9-29.0), lower respiratory tract disorder (16.3%, 95% CI: 8.9-26.2) and traumatic injury (13.8%, 95% CI: 7.1-23.3). The most common specific disorders were periodontal disease (13.5%, 95% CI: 12.6-14.4), obesity (5.9%, 95% CI: 5.3-6.5), retained deciduous dentition (5.7%, 95% CI: 5.1-6.4), anal sac impaction (4.9%, 95% CI: 4.4-5.5) and aggression (4.2%, 95% CI: 3.7-4.8). Among the 28 most common fine-level disorders, males had statistically (P <  0.005) higher probability than females for 5 disorders (aggression, heart murmur, otitis externa, conjunctivitis and upper respiratory tract infection). There were no disorders with statistically (P <  0.005) higher prevalence in females.

CONCLUSIONS

This study documented rising ownership and a currently youthful population of Chihuahuas in the UK. These results suggest that the Chihuahua is currently undergoing a popularity boom but veterinarians need to be watchful for welfare issues related to impulse purchase of Chihuahua puppies by owners with limited experience of dog care. Periodontal disease, obesity, retained deciduous dentition, anal sac impaction and aggression were identified as common health issues within the breed. The unique veterinary care needs of this popular miniature breed suggest that veterinarians should consider the value of advanced training in anesthesia and dentistry in small-sized dogs.

Dimensões da patela relacionadas à massa corporal do cão para emprego na confecção de prótese: estudo em cadáver

RESUMO O objetivo deste trabalho foi mensurar as dimensões da patela de cadáveres caninos e avaliar sua relação com a massa corporal. Para a realização das medidas patelares, foram utilizados 70 cadáveres de cães adultos, com massa corpórea de 1 a 50kg, sem evidência clínica de afecção na articulação femorotibiopatelar. Com auxílio de um paquímetro, foram mensurados os comprimentos externo e interno, a largura externa no terço médio, a largura e a espessura internas nos terços proximal, médio e distal das patelas. Também foram mensuradas a largura nos terços proximal, médio e distal, a profundidade nos terços proximal, médio e distal do sulco troclear; essas medidas foram exclusivamente internas. Observou-se, de forma geral, forte correlação entre as medidas patelares e a massa corporal de cadáveres de cães. Nas condições deste estudo, pode-se concluir que o tamanho da patela varia segundo a massa corporal do cão e que essas medidas devem ser consideradas ao se planejar uma substituição protética.

Nutrition consultation for an overweight growing Bernese Mountain Dog-A case report

In growing dogs, overweight is assimilated and attributed to a fast growth rate. Proper nutrition plays a very important role during growth as mistakes in feeding may lead to severe disease. This case report is an example for excessive weight gain during growth that, particularly in large breed dogs, may lead to skeletal disorders such as improper alignments of the limbs. If body weight gain exceeds the ideal range of the individual growth curve (by initially 4 kg in this case), fast growth may lead to growth disturbances and associated chronic diseases. These cases require a dietary adaption. However, the success in the nutritional management of the body weight relies largely on the owner's compliance.

A Review of the Impact of Neuter Status on Expression of Inherited Conditions in Dogs

Gonadectomy is an important reproductive management tool employed in many countries, and is highly prevalent in the US with an estimated 85% of dogs being neutered. Despite the societal benefits in pet population control, negative associations between neuter status, and health conditions have been reported in recent years. Most particularly observed are the consequences of early age neutering. Knowing that different physiological systems rely upon gonadal steroids during development and physiological maintenance, studies have been undertaken to assess the impact of neuter status on multiple body and organ systems. For some inherited conditions, neutering is associated with an increased risk of expression. Neutering has also been associated with altered metabolism and a predisposition for weight gain in dogs, which may confound the detected risk association between neutering and disease expression. This review summarizes the effects of neutering on cancer, orthopedic, and immune disorders in the dog and also explores the potentially exacerbating factor of body weight.

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.

Breed susceptibility for common surgically treated orthopaedic diseases in 12 dog breeds

Background

A retrospective case–control study was conducted to estimate breed predisposition for common orthopaedic conditions in 12 popular dog breeds in Norway and Sweden. Orthopaedic conditions investigated were elbow dysplasia (ED); cranial cruciate ligament disease (CCLD); medial patellar luxation (MPL); and fractures of the radius and ulna. Dogs surgically treated for the conditions above at the Swedish and Norwegian University Animal Hospitals between the years 2011 and 2015 were compared with a geographically adjusted control group calculated from the national ID-registries. Logistic regression analyses (stratified for clinic and combined) were used to calculate odds ratios (OR) and 95% confidence intervals. Mixed breed dogs were used as reference.

Results

Breeds found at-risk for ED were the Labrador retriever (OR = 5.73), the Rottweiler (OR = 5.63), the German shepherd dog (OR = 3.31) and the Staffordshire bull terrier (OR = 3.08). The Chihuahua was the only breed where an increased risk for MPL (OR = 2.80) was identified. While the Rottweiler was the only breed predisposed for CCLD (OR = 3.96), the results were conflicting for the Labrador retriever (OR = 0.44 in Sweden, 2.85 in Norway); the overall risk was identical to mixed-breed dogs.

Conclusions

Most results are in concordance with earlier studies. However, an increased risk of CCLD was not identified for the Labrador retriever, the Staffordshire bull terrier was found to have an increased risk of ED and some country-specific differences were noted. These results highlight the importance of utilising large caseloads and appropriate control groups when breed susceptibility is reported.

Electronic supplementary material

The online version of this article (10.1186/s13028-019-0454-4) contains supplementary material, which is available to authorized users.