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Abstract

Objective: The aim of this study was to describe clinical and imaging features of thoracic vertebral canal stenosis secondary to the hypertrophy of the vertebral lamina and articular processes in screw-tail brachycephalic dog breeds, to evaluate the prevalence of the malformation in a large group of screw-tail dog breeds and to determine if degree of stenosis is associated with presence of neurological signs. Study design: This is a retrospective multicentric study. Materials and methods: Clinical records of 185 screw-tail brachycephalic dogs (French Bulldogs, English Bulldogs, Boston Terriers) and Pugs were reviewed. Ten dogs with neurological deficits secondary to thoracic vertebral canal stenosis diagnosed on magnetic resonance imaging were identified (Group 1). Neurologically normal dogs (n = 175) of the same breeds underwent computed tomographic imaging of the thoracic vertebral column for other medical reasons (Group 2). Cross-sectional measurements were used to calculate a stenotic ratio. Results: Group 1 consisted of three French Bulldogs, six English Bulldogs and one Pug. Eight were males. Most dogs presented with progressive non-painful pelvic limbs ataxia and paresis. Twenty stenotic sites were identified with the most common being T4-T5. Three of ten dogs were treated surgically and all had a good long-term outcome. In Group 2, 33 of 175 dogs had one or more stenotic sites with the most common being T2-T3. The degree of the stenosis was significantly higher in Group 1 (p = 0.019). A stenotic ratio of 0.56 had sensitivity and specificity of 67% to differentiate between dogs with and without neurological signs. Conclusion: Cranial thoracic vertebral canal stenosis is observed predominantly in young male Bulldogs, but not all stenoses are clinically relevant.

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... The prevalence and type of disorders affecting the cranial thoracic vertebral column in dogs has been scarcely described in the veterinary literature. These are limited to case reports, small case series or sporadic cases within larger studies describing intervertebral disc disease (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17), calcinosis circumscripta (18,19), congenital malformations [cranial thoracic vertebral canal stenosis (20)(21)(22)(23), thoracic vertebral body malformations (24)(25)(26)(27)(28), spinal arachnoid diverticula (29), spina bifida ± other associated abnormalities (30)(31)(32)(33)], neoplasia [chondrosarcoma (34), meningioma (13,35), multiple myeloma (36), myxosarcoma (37), nerve sheath tumour (35)], discospondylitis (14,38) or fracture/luxation (14,39). To the authors' knowledge, there are no studies dedicated to the description of the signalment, clinical signs and clinical prevalence of the different disease processes affecting this particular region of the vertebral column. ...
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The aim of the study was to describe the signalment, clinical presentation and presumptive or final diagnoses of dogs with cranial thoracic spinal cord lesions identified on advanced imaging. Retrospective evaluation of the databases of three veterinary specialty centres, between 2009 and 2021, was performed to identify dogs with a lesion affecting the cranial thoracic vertebral column (T1-T6 vertebrae) as the primary cause for presenting signs of myelopathy and/or spinal pain. Eighty-four dogs were included in the study, with the majority (n = 76) presenting with a progressive history of over four-weeks’ duration. On neurologic examination, most dogs were ambulatory (n = 64), and the most common neuroanatomic localisation was the T3-L3 spinal cord segments (n = 63). Twelve dogs (14%) showed a short-strided thoracic limb gait on clinical examination. The most common diagnosis was neoplasia (n = 33), followed by anomalies (n = 22, including vertebral body malformations in 14 dogs) and degenerative disorders (n = 16, with intervertebral disc protrusion diagnosed in 9 dogs). The most common vertebrae affected were T3 and T5. Most dogs with degenerative conditions showed asymmetric clinical signs, and the majority of dogs with neoplasia showed signs of spinal hyperaesthesia on examination. The findings of this study describe the clinical signs and presumptive or final diagnoses associated with lesions affecting the cranial thoracic spinal cord. When combined with the signalment and clinical history, this information can assist in both the recognition of and problem-based approach to these cases.
... Among the three breeds with extreme brachycephalic conformations, English Bulldogs, French Bulldogs and Pugs, facial (facial, nasal and peri-ocular) locations of fold dermatitis were common; this could reflect the failure of muzzle skin to be reduced in proportion to the extreme brachycephalic facial skeleton. A high frequency of tail fold dermatitis was also recorded in English Bulldogs and French Bulldogs, two breeds that commonly show screw tails 33,34 . Conversely, high frequency of fold dermatitis in locations other than the face was shown www.nature.com/scientificreports/ in the Bassett Hound and Shar Pei, two breeds with breed standards that promote wide-spread wrinkling of body and extremities 29 . ...
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Skin fold dermatitis (intertrigo) is an inflammatory process of closely apposing skin surfaces. Extreme conformations towards folded skin in many dog breeds are linked with higher risk. Using anonymised primary-care veterinary data from the VetCompass Programme, this study aimed to report the frequency, demographic risk factors and clinical management for skin fold dermatitis in the UK. Risk factor analysis used random effects multivariable logistic regression modelling. From a study population of 905,553 dogs, the one-year period prevalence in dogs overall was 0.37% (95% CI 0.35–0.39). Diagnosis was supported by laboratory testing in 4.21% cases. Systemic antibiosis was used in 42.30% cases. Compared with crossbreed dogs, the most highly predisposed breeds were English Bulldog (odds ratio [OR] 49.07, 95% CI 37.79–63.70), French Bulldog (OR 25.92, 95% CI 19.62–34.26,) and Pug (OR 16.27, 95% CI 12.20–21.69). The most protected breeds were Yorkshire Terrier (OR 0.14, 95% CI 0.03–0.56), Border Collie (OR 0.31, 95% CI 0.11–0.84), Jack Russell Terrier (OR 0.53, 95% CI 0.30–0.92) and Labrador Retriever (OR 0.57, 95% CI 0.35–0.93). This study adds further evidence to the welfare concerns around high popularity of dog breeds with extreme conformations. The three breeds with by far the highest odds of skin fold dermatitis represent an extreme brachycephalic conformation.
... At the grouped disorder level, marked protections (OR < 0.5) were reported for appetite disorder (OR 0.43), spinal cord disorder (0.31) and dental disorder (0.25). Some of these protections are somewhat surprising; for example, given the breed's documented high incidence of hemivertebrae and other vertebral malformations [15,[71][72][73], it is unexpected but reassuring to find that this does not apparently translate into a high level of spinal cord disorder, and may be explained by previous findings that hemivertebrae is more commonly associated with a neurologically normal phenotype in English Bulldogs than for Pugs (Ryan et al., 2017). It is also surprising that a breed with a high prevalence of many other descriptors for skin disease has an apparent protection for pruritus: perhaps this descriptor was subsumed within other more clinically precise descriptors, such as dermatitis or atopic dermatitis, and hence appears artefactually low. ...
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Background The English Bulldog has risen sharply in popularity over the past decade but its distinctive and extreme conformation is linked to several serious health conditions. Using multivariable analysis of anonymised veterinary clinical data from the VetCompass Programme, this study compared the odds of common disorders between English Bulldogs and all remaining dogs in the UK during 2016. Results From 905,544 dogs under veterinary care during 2016, the analysis included a random sample of 2,662 English Bulldogs and 22,039 dogs that are not English Bulldogs. English Bulldogs had 2.04 times the odds of diagnosis with ≥ 1 disorder than dogs that are not English Bulldogs (95% confidence interval [CI] 1.85 to 2.25). At a specific-level of diagnostic precision, English Bulldogs had increased odds of 24/43 (55.8%) disorders. These included: skin fold dermatitis (odds ratio [OR] 38.12; 95% CI 26.86 to 54.10), prolapsed nictitating membrane gland (OR 26.79; 95% CI 18.61 to 38.58) and mandibular prognathism (OR 24.32; 95% CI 13.59 to 43.53). Conversely, English Bulldogs had significantly reduced odds of 6/43 (14.0%) disorders. These included: retained deciduous tooth (OR 0.02; 95% CI 0.01 to 0.17), lipoma (OR 0.06; 95% CI 0.01 to 0.40) and periodontal disease (OR 0.23; 95% CI 0.18 to 0.30). At a grouped-level of diagnostic precision, English Bulldogs had significantly increased odds of 17/34 (50.0%) disorders. These included: congenital disorder (OR 7.55; 95% CI 5.29 to 10.76), tail disorder (OR 6.01; 95% CI 3.91 to 9.24) and lower respiratory tract disorder (OR 5.50; 95% CI 4.11 to 7.35). Conversely, English Bulldogs had significantly reduced odds of 3/34 (8.8%) disorders. These were: dental disorder (OR 0.25; 95% CI 0.20 to 0.31), spinal cord disorder (OR 0.31; 95% CI 0.14 to 0.71) and appetite disorder (OR 0.43; 95% CI 0.20 to 0.91). Conclusions These results suggest that the health of English Bulldogs is substantially lower than dogs that are not English Bulldogs and that many predispositions in the breed are driven by the extreme conformation of these dogs. Consequently, immediate redefinition of the breed towards a moderate conformation is strongly advocated to avoid the UK joining the growing list of countries where breeding of English Bulldogs is banned.
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Dogs presenting with brachycephalic obstructive airway syndrome suffer from multilevel obstruction of the airway as well as secondary structural collapse. Stenotic nares, aberrant turbinates, nasopharyngeal collapse, soft palate hyperplasia, macroglossia, tonsillar hypertrophy, laryngeal collapse, and left bronchial collapse are described as the most common associated anomalies. Rhinoplasty and palatoplasty as well as newer surgical techniques and prudent preoperative and postoperative care strategies have resulted in significant improvement even in middle-aged dogs.
Article
The authors have observed a vertebral anomaly in French and English Bulldogs and termed this anomaly “vertebral vascular canal dysplasia (VVCD).” No previously published descriptions of this anomaly were found. The aims of this retrospective, multi‐institutional, observational study were to (1) describe the clinical, CT, and MRI characteristics of VVCD, and (2) estimate the prevalence and describe the characteristics of VVCD in a group of French and English Bulldogs. For descriptions of the anomaly, medical records and imaging studies of nine clinical cases with VVCD from several countries were reviewed. For estimation of prevalence, imaging studies of French and English Bulldogs from the United Kingdom (UK) and Italy were reviewed. All clinical case dogs had ≥5 thoracic vertebrae with VVCD affecting >50% of vertebral body height (VBH). The prevalence of VVCD involving ≥1 thoracic vertebra in the UK population (CT identified) of English Bulldogs and French Bulldogs was, respectively, 83.3% (30/36) and 68.3% (28/41). English Bulldogs had significantly more thoracic vertebrae with VVCD than French Bulldogs (P = < 0.01). The prevalence of VVCD in ≥1 thoracic vertebra in the Italian population (MRI identified) of English Bulldogs and French Bulldogs was, respectively, 21.7% (5/23) and 6.6% (7/106). Vertebral vascular canal dysplasia was observed in normal as well as in malformed vertebrae (e.g., hemivertebrae). Findings from the current study introduced descriptions of VVCD that can be used as background for future studies.
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There are nearly 400 modern domestic dog breeds with a unique histories and genetic profiles. To track the genetic signatures of breed development, we have assembled the most diverse dataset of dog breeds, reflecting their extensive phenotypic variation and heritage. Combining genetic distance, migration, and genome-wide haplotype sharing analyses, we uncover geographic patterns of development and independent origins of common traits. Our analyses reveal the hybrid history of breeds and elucidate the effects of immigration, revealing for the first time a suggestion of New World dog within some modern breeds. Finally, we used cladistics and haplotype sharing to show that some common traits have arisen more than once in the history of the dog. These analyses characterize the complexities of breed development, resolving longstanding questions regarding individual breed origination, the effect of migration on geographically distinct breeds, and, by inference, transfer of trait and disease alleles among dog breeds.
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Background: This study examines genetic diversity among 102 registered English Bulldogs used for breeding based on maternal and paternal haplotypes, allele frequencies in 33 highly polymorphic short tandem repeat (STR) loci on 25 chromosomes, STR-linked dog leukocyte antigen (DLA) class I and II haplotypes, and the number and size of genome-wide runs of homozygosity (ROH) determined from high density SNP arrays. The objective was to assess whether the breed retains enough genetic diversity to correct the genotypic and phenotypic abnormalities associated with poor health, to allow for the elimination of deleterious recessive mutations, or to make further phenotypic changes in body structure or coat. An additional 37 English bulldogs presented to the UC Davis Veterinary Clinical Services for health problems were also genetically compared with the 102 registered dogs based on the perception that sickly English bulldogs are products of commercial breeders or puppy-mills and genetically different and inferior. Results: Four paternal haplotypes, with one occurring in 93 % of dogs, were identified using six Y-short tandem repeat (STR) markers. Three major and two minor matrilines were identified by mitochondrial D-loop sequencing. Heterozygosity was determined from allele frequencies at genomic loci; the average number of alleles per locus was 6.45, with only 2.7 accounting for a majority of the diversity. However, observed and expected heterozygosity values were nearly identical, indicating that the population as a whole was in Hardy-Weinberg equilibrium (HWE). However, internal relatedness (IR) and adjusted IR (IRVD) values demonstrated that a number of individuals were the offspring of parents that were either more inbred or outbred than the population as a whole. The diversity of DLA class I and II haplotypes was low, with only 11 identified DLA class I and nine class II haplotypes. Forty one percent of the breed shared a single DLA class I and 62 % a single class II haplotype. Nineteen percent of the dogs were homozygous for the dominant DLA class I haplotype and 42 % for the dominant DLA class II haplotype. The extensive loss of genetic diversity is most likely the result of a small founder population and artificial genetic bottlenecks occurring in the past. The prominent phenotypic changes characteristic of the breed have also resulted in numerous large runs of homozygosity (ROH) throughout the genome compared to Standard Poodles, which were phenotypically more similar to indigenous-type dogs. Conclusions: English bulldogs have very low genetic diversity resulting from a small founder population and artificial genetic bottlenecks. Although some phenotypic and genotypic diversity still exists within the breed, whether it is sufficient to use reverse selection to improve health, select against simple recessive deleterious traits, and/or to accommodate further genotypic/phenotypic manipulations without further decreasing existing genetic diversity is questionable.
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Article
OBJECTIVE To investigate whether hemivertebra subtype as determined via CT was associated with breed and Cobb angle (a measure of the degree of spinal curvature) in apparently neurologically normal French Bulldogs, English Bulldogs, and Pugs. ANIMALS Client-owned French Bulldogs (n = 58), English Bulldogs (30), and Pugs (12) with thoracic hemivertebrae that underwent CT for reasons unrelated to spinal disease. PROCEDURES CT scans of each dog were evaluated, and hemivertebrae were categorized by subtype (ventral aplasia, ventral hypoplasia, lateral aplasia, lateral hypoplasia, ventrolateral aplasia, ventrolateral hypoplasia, ventral and median aplasia, ventral and median hypoplasia, and symmetric hypoplasia). The Cobb angle was measured, and kyphosis was defined as a Cobb angle > 10°. Results were compared among breeds. RESULTS 243 hemivertebrae were identified in the French Bulldog group, 100 in the English Bulldog group, and 19 in the Pug group. Breed was significantly associated with hemivertebra subtype. Pugs were more likely than French and English Bulldogs to have ventral hypoplasia and less likely to have ventral and median hypoplasia. English Bulldogs were more likely than French Bulldogs to have ventral and median hypoplasia. Compared with other hemivertebra subtypes, ventral hypoplasia was associated with a greater Cobb angle and a higher likelihood of kyphosis. Pugs were more likely than the other 2 breeds to have kyphosis. CONCLUSIONS AND CLINICAL RELEVANCE Pugs had a different spectrum of hemivertebra subtypes than French and English Bulldogs in this study. Additional research is necessary to evaluate the clinical relevance of this finding.
Article
The aims of this study were to evaluate the prevalence and anatomical characteristics of thoracic caudal articular process dysplasia in French bulldogs, English bulldogs and Pugs presenting for problems unrelated to spinal disease. In this retrospective cross-sectional study, computed tomography scans of the thoracic vertebral column of these three breeds were reviewed for the presence and location of caudal articular process hypoplasia and aplasia, and compared between breeds. A total of 271 dogs met the inclusion criteria: 108 French bulldogs, 63 English bulldogs, and 100 Pugs. A total of 70.4% of French bulldogs, 84.1% of English bulldogs, and 97.0% of Pugs showed evidence of caudal articular process dysplasia. Compared to French and English bulldogs, Pugs showed a significantly higher prevalence of caudal articular process aplasia, but also a lower prevalence of caudal articular process hypoplasia, a higher number of affected vertebrae per dog and demonstrated a generalized and bilateral spatial pattern more frequently. Furthermore, Pugs showed a significantly different anatomical distribution of caudal articular process dysplasia along the vertebral column, with a high prevalence of caudal articular process aplasia between T10 and T13. This area was almost completely spared in French and English bulldogs. As previously suggested, caudal articular process dysplasia is a common finding in neurologically normal Pugs but this also seems to apply to French and English bulldogs. The predisposition of clinically relevant caudal articular process dysplasia in Pugs is possibly not only caused by the higher prevalence of caudal articular process dysplasia, but also by breed specific anatomical characteristics.
Article
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Article
A four-month-old male entire Rottweiler presented for progressive pelvic limb ataxia. Neurological examination revealed non-ambulatory paraparesis with ataxia in pelvic limbs, absent pelvic limb postural reactions, clonic patellar reflexes, normal withdrawal reflexes in all limbs and hyperaesthesia on neck manipulation. Weight shifting and splaying of the thoracic limbs (representing either mild paresis or compensatory gait change) were also noted. Neurolocalisation was third thoracic to third lumbar spinal cord segments (Th3-L3), most likely within the cranial aspect of this region. MRI showed enlargement of the dorsal laminae and articular processes …
Article
Congenital vertebral malformations are common incidental findings in small breed dogs. This retrospective observational study evaluated the type and prevalence of thoracic vertebral malformations in 171 neurologically normal and 10 neurologically abnormal screw-tailed brachycephalic dogs. Neurologically normal dogs underwent CT for reasons unrelated to spinal disease, while affected dogs underwent MRI. Imaging studies were reviewed and vertebral malformations including hemivertebrae, block vertebrae, transitional vertebrae, and spina bifida were documented. The group of clinically normal dogs consisted of 62 French bulldogs, 68 Pugs and 41English bulldogs. The group of affected dogs consisted of one French bulldog and nine Pugs. Overall, 80.7% of neurologically normal animals were affected by at least one vertebral malformation. There was a significant influence of breed, with thoracic vertebral malformations occurring more often in neurologically normal French bulldogs (P<0.0001)and English bulldogs (P=0.002). Compared to other breeds, hemivertebrae occurred more often in neurologically normal French bulldogs (93.5%; P< 0.0001 vs. Pugs; P=0.004 vs. English bulldogs) and less often in neurologically normal Pugs (17.6%; P=0.004 vs. English bulldogs). Neurologically normal Pugs were more often diagnosed with transitional vertebrae and spina bifida compared to other breeds (P<0.0001 for both malformations). Of Pugs included in the study, 4.7% were diagnosed with clinically relevant thoracic vertebral malformations. When compared to the general veterinary hospital population, this was significantly more than the other two breeds (P= 0.006). This study indicates that thoracic vertebral malformations occur commonly in neurologically normal screw-tailed brachycephalic dogs. While hemivertebrae are often interpreted as incidental diagnostic findings, they appear to be of greater clinical importance in Pugs compared to other screw- tailed brachycephalic breeds.
Article
Congenital vertebral malformations are common in brachycephalic “screw-tailed” dog breeds such as French bulldogs, English bulldogs, Boston terriers, and pugs. The aim of this retrospective study was to determine whether a radiographic classification scheme developed for use in humans would be feasible for use in these dog breeds. Inclusion criteria were hospital admission between September 2009 and April 2013, neurologic examination findings available, diagnostic quality lateral and ventro-dorsal digital radiographs of the thoracic vertebral column, and at least one congenital vertebral malformation. Radiographs were retrieved and interpreted by two observers who were unaware of neurologic status. Vertebral malformations were classified based on a classification scheme modified from a previous human study and a consensus of both observers. Twenty-eight dogs met inclusion criteria (12 with neurologic deficits, 16 with no neurologic deficits). Congenital vertebral malformations affected 85/362 (23.5%) of thoracic vertebrae. Vertebral body formation defects were the most common (butterfly vertebrae 6.6%, ventral wedge-shaped vertebrae 5.5%, dorsal hemivertebrae 0.8%, and dorso-lateral hemivertebrae 0.5%). No lateral hemivertebrae or lateral wedge-shaped vertebrae were identified. The T7 vertebra was the most commonly affected (11/28 dogs), followed by T8 (8/28 dogs) and T12 (8/28 dogs). The number and type of vertebral malformations differed between groups (P = 0.01). Based on MRI, dorsal, and dorso-lateral hemivertebrae were the cause of spinal cord compression in 5/12 (41.6%) of dogs with neurologic deficits. Findings indicated that a modified human radiographic classification system of vertebral malformations is feasible for use in future studies of brachycephalic “screw-tailed” dogs.
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A three-year-old Border collie was diagnosed with a bipartite atlas and bilateral forelimb hypodactyly. The dog showed signs of acute, non-progressive neck pain, general stiffness and right thoracic limb non-weight-bearing lameness. Computed tomography imaging revealed a bipartite atlas with abaxial vertical bone proliferation, which was the cause of the clinical signs. In addition, bilateral hypodactyly of the second and fifth digits was incidentally found. This report suggests that hypodactyly may be associated with atlas malformations.
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ABSTRACTA three-month-old female basset hound was referred to the Norwegian College of Veterinary Medicine with a history of progressive paresis of the pelvic limbs. Following neurological examination and the study of myelograms, extradural masses causing spinal cord compressions at the T12.13 and T13-L1 junctions were diagnosed. At necropsy bone-tissue of the vertebral laminae was found to have formed stenoses of the vertebral canal producing compressions of the spinal cord. Irreversible tissue-damage was observed in histological sections prepared from the compressed areas of the spinal cord.
Article
The clinical, morphologic, and morphometric features of cranial thoracic spinal stenosis were investigated in large and giant breed dogs. Seventy-nine magnetic resonance imaging studies of the cranial thoracic spine were assessed. Twenty-six were retrieved retrospectively and 53 were acquired prospectively using the same inclusion criteria. Images were evaluated using a modified compression scale as: no osseous stenosis (grade 0), osseous stenosis without spinal cord compression (grade 1), and osseous stenosis with spinal cord compression (grade 2). Morphometric analysis was performed and compared to the subjective grading system. Grades 1 and 2 cranial thoracic spinal stenosis were identified on 24 imaging studies in 23 dogs. Sixteen of 23 dogs had a conformation typified by Molosser breeds and 21/23 were male. The most common sites of stenosis were T2-3 and T3-4. The articular process joints were enlarged with abnormal oblique orientation. Stenosis was dorsolateral, lateralized, or dorsoventral. Concurrent osseous cervical spondylomyelopathy was recognized in six dogs and other neurologic disease in five dogs. Cranial thoracic spinal stenosis was the only finding in 12 dogs. In 9 of these 12 dogs (all grade 2) neurolocalization was to the T3-L3 spinal segment. The median age of these dogs was 9.5 months. In the remaining three dogs neurologic signs were not present. Stenosis ratios were of limited benefit in detecting stenotic sites. Grade 2 cranial thoracic spinal stenosis causing direct spinal cord compression may lead to neurologic signs, however milder stenosis (grade 1) is likely to be subclinical or incidental.
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Congenital anomalies of the spine are common in small animals. The type of deformity, location, severity, time of onset of associated clinical signs, and progression of neurologic dysfunction varies widely. To promote clearer understanding, the authors present the various spinal malformations using modified human classification schemes and use current widely accepted definitions and terminology. The diagnostic approach, including utilization of advanced imaging, and surgical management is emphasized.
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Cervical spondylomyelopathy (CSM) is a common and controversial disease of the cervical spine of large and giant breed dogs. Not many diseases in veterinary medicine have been referred to by 14 different names and have had 21 surgical techniques proposed to treat it. This article reviews the current knowledge of CSM with regard to its etiology, pathophysiology, diagnosis, treatment, and outcome.
Article
To evaluate agreement and repeatability of vertebral column measurements using computed tomography (CT) and magnetic resonance imaging (MRI). Retrospective observational study. ANIMALS; Dogs (n=18) with disc associated wobbler syndrome; Dog cadavers (n=3). Five measurements of the 5th cervical vertebra were performed: vertebral body length (VBL), vertebral canal height (VCH), vertebral body height (VBH), vertebral canal width (VCW), and vertebral body width (VBW). Measurements were performed independently twice by 2 observers. Bland-Altman plots were created to evaluate agreement. Cadaveric vertebrae with soft tissue removed had the same variables and actual dimensions measured. The largest discrepancy between CT and MRI measurement was for VBL (mean difference+/-SD=1.262 mm+/-1.245; P<.001), with the difference for all the other variables being acceptable. The 1st measurement was significantly higher than the 2nd only for VBL using CT (mean difference=0.476 mm+/-1.120; P=.009), with all other variables having acceptable differences. Mean difference for all measurements between 2 observers was small, except for VBL using CT (mean difference=0.762 mm+/-1.042; P<.001). Only the difference for VBL between CT and cadaver specimens was statistically significant. Our results suggest high repeatability and good agreement for most vertebral measurements of interest. VBL measurement using CT was considered problematic. Provided limitations are understood, linear measurements of vertebral dimensions from CT and MRI images can be used clinically.
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This case report describes a novel developmental vertebral malformation in two young Dogues de Bordeaux, which was diagnosed by magnetic resonance imaging. Both dogs were treated surgically with reasonable success.
Article
The incidence of facet aplasia was investigated in three groups of pure-bred dogs. We examined large breeds (Rough Collies, Doberman Pinschers, Rottweilers, Bernese Mountain Dogs, German Shepherd Dogs), chondrodystrophic breeds (Dachshunds, Pekinese dogs), and small breeds (Yorkshire Terriers, Maltese dogs). Uni- or bilateral aplasia of zygapophyseal (facet) joints was exclusively found in juvenile and adult small dogs, in which the incidence of aplasia ranged from between 26% (Th1) and 63% (Th8). There was no evidence that aplasia of zygapophyseal joints increases the risk of developing intervertebral disc disease or deformative spondylosis in small breeds. By applying the findings of previous empirical studies on intervertebral disc geometry and its biomechanical behaviour on the present morphometric results, there was an indication that the intervertebral disc may well compensate for the functional loss of aplastic zygapophyseal joints in small dogs. Biomechanical factors and their potential role as inducing agents of facet aplasia in the pre-diaphragmatic thoracic spine are also discussed.
Article
Computed tomographic images of the thoracic spine of 13 German shepherd dogs were examined in order to determine the thoracic spine morphometry. Examinations were carried out in the transverse plane both intervertebral and mid-vertebral levels of the each thoracic vertebrae. The dorsoventral and interpedicular diameters of the spinal canal, the dorsoventral and transverse diameters of the vertebral body, the dorsoventral and transverse diameters of the spinal cord and also the cross-section area of the spinal canal were measured. The maximum values were found to be at the level of C7-T1. The shapes of the spinal canal and cord were circular in middle part, the shape became transverse oval in the cranial and caudal parts of the thoracic spine. The most significant correlation between the diameters was found to be in male dogs, except between dorsoventral diameters of the spinal canal and that of the vertebral body and between dorsoventral diameters of the spinal canal and transverse diameters of the vertebral body.
Article
Clinical findings in six dogs with asymmetrical, transitional, lumbosacral vertebral segments are reported. All dogs exhibited low back pain and varying degrees of asymmetrical cauda equina dysfunction. Results of myelography, epidurography, and magnetic resonance imaging (MRI) indicated a unilateral disk protrusion in all dogs. In the dogs with MRIs, focal degenerative alterations in the vertebral end plates and adjacent body of the vertebra were detected. All dogs were treated with a dorsal laminectomy or hemilaminectomy. Results following surgery were good or excellent in all six dogs.
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Prevalence and magnetic resonance imaging of intervertebral disc disease in pugs with caudal articular facet dysplasia of the thoracolumbar spine
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Incidence of vertebral anomalies in Pug dogs; implications for myelopathies?
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