Lumbosacral stenosis in 29 military working dogs: epidemiologic findings and outcome after surgical intervention (1990-1999)

Evaluation of the thermographic response of the lumbar region in dogs with bilateral hip osteoarthritis

Infrared thermography is suggested as a method of medical assistance for evaluating anatomical regions where there may be some inflammatory or painful condition that requires immediate medical attention. For this reason, this study aimed to characterize digital thermography of the lumbar region in police working dogs with hip osteoarthritis, 47 dogs with bilateral hip osteoarthritis were evaluated. A thermographic dorsoventral view of the dogs' backs were obtained, and mean and maximum temperatures were determined. In addition, results from the Canine Brief Pain Inventory, Liverpool Osteoarthritis in Dogs (LOAD), the Canine Orthopedic Index, and weight-bearing distribution evaluation were collected. Results were compared with an Independent Samples T-Test or ANOVA, followed by an LSD post hoc. Multiple regression was run to predict temperatures from age, sex, breed, body weight, and Orthopedic Foundation for Animals hip score and to predict clinical metrology scores and weight-bearing distribution results from temperature results. The sample included 28 males and 19 females, with a mean age of 6.3 ± 2.5 years and bodyweight of 26.9 ± 5.1 kg, with osteoarthritis hip scores of mild (70.2%), moderate (21.3%), and severe (8.5%). Significant differences were observed in mean temperatures between German Shepherd Dogs (GSD) and Labrador Retrievers (LR) (p < 0.01), and LR and Belgian Malinois (BM) (p=0.02). Mean temperature contributed to the prediction of LOAD and stiffness. LR showed significantly higher temperature values than GSD and BM. No differences were observed between osteoarthritis hip scores and mean temperature values contributed to LOAD scores' prediction. This relation needs to be addressed in further studies, involving a larger number of animals, and to determine changes in response to treatment.

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

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

Postoperative outcomes of combined surgery comprising dorsal laminectomy, transarticular screws, pedicle screws and polymethylmethacrylate for dorsal fixation in 21 dogs with degenerative lumbosacral stenosis

OBJECTIVE

To retrospectively review the efficacy of combined surgery comprising dorsal laminectomy and dorsal fixation using screws and polymethylmethacrylate as treatment for dogs with degenerative lumbosacral stenosis (DLSS).

ANIMALS

21 client owned dogs diagnosed with DLSS and treated surgically.

PROCEDURES

Based on clinical records, signalments, clinical signs, findings from orthopedic and neurological examinations, imaging findings, and postoperative complications were evaluated at the following time points: preoperatively, postoperatively, and 3, 6, 12, 24, and 36 months after surgery.

RESULTS

In all 21 cases, clinical signs were alleviated, proprioceptive deficits were improved from 3 months after surgery, and no recurrence of clinical signs was observed during the observation period. Minor complications were observed in 6 cases (28.6%), including implant failure in 2 (9.5%), delayed healing of surgical wounds in 2 (9.5%), seroma in 1 (4.8%), and swelling of the affected area in 1 (4.8%). There was no case with major complications.

CLINICAL RELEVANCE

Combined surgery comprising dorsal laminectomy and dorsal fixation using screws and polymethylmethacrylate is a useful treatment that can improve long-term clinical signs in dogs with DLSS.

Retrospective Preliminary Assessment of Routine Follow-Up Low-Field Magnetic Resonance Imaging in Dogs Presumptively Diagnosed With Discospondylitis

Background

The usefulness of routine follow-up Magnetic Resonance Imaging (MRI-2) in asymptomatic dogs treated for discospondylitis is unknown.

Methods

This cross-sectional retrospective study investigated the features of MRI-2 in a heterogeneous group of dogs treated for discospondylitis, and if these were associated with the presence or absence of clinical signs. After comparing initial MRI (MRI-1) and MRI-2, an observer, blinded to the dog's clinical signs, described the MRI-2 findings. The study population was then divided into symptomatic or asymptomatic at the time of MRI-2. Two separate observers subjectively classified the discospondylitis as active or inactive. Repeatability and interobserver agreement were evaluated.

Results

A total of 25 dogs were included. At the time of MRI-2 16 (64%) dogs were asymptomatic and 9 (36%) were symptomatic. Based on MRI-2, 20 (80%) and 18 (72%) out of 25 dogs were considered to have active discospondylitis by the first and second observers, respectively. Interobserver agreement was moderate. No MRI-2 features were associated with the clinical status. The subjective classification of inactive discospondylitis was significantly associated with asymptomatic clinical status, but the classification of active discospondylitis was evenly distributed between groups.

Conclusion

This study did not identify a meaningful association between the clinical status of dogs treated for presumptive discospondylitis and MRI-2 results. There were no specific MRI-2 features which were associated with the clinical status.

A survey on the orthopedic and functional assessment in a Portuguese population of police working dogs

BACKGROUND

Working dogs are at an increased risk of developing an orthopedic disease compared to companion dogs. This study aimed to evaluate functional and orthopedic index fitness in a Portuguese population of police working dogs. In an observational, prospective study, information on 165 dogs was collected. The age, sex, breed, specific work, and history of previous diagnosis of orthopedic disease were recorded for each patient. A copy of the Canine Orthopedic Index (COI), Hudson Visual Analogue Scale (HVAS), and Functional Assessment (FA) was collected for all dogs. COI, HVAS, and FA scores between breeds, work, age, sex, and history of a previous diagnosis of orthopedic disease were compared. Multiple regression was run to predict COI, HVAS, and FA scores from breeds, work, age, sex, and history of orthopedic disease. Correlations between items were determined with Pearson's correlation. A p < 0.05 was set.

RESULTS

The sample was composed of 92 males and 73 females, with a mean age of 5.2 ± 3.2 years. Four main dog breeds were represented, 60 Belgian Malinois Shepherd Dogs, 52 German Shepherd Dogs, 29 Labrador Retrievers, and 14 Dutch Shepherd Dog. A prevalence of diarrhea of 10.6% was determined, with 4% of dogs having liquid diarrhea. German Shepherd Dogs had significantly higher FA scores (p = 0.03). Dogs with a history of previous veterinary assistance due to orthopedic issues had significantly lower HVAS scores and higher scores with all remaining questionnaires (p < 0.01 for all). No differences were found between sexes or specific work. Age and a history of orthopedic disease contributed to the prediction of all scores. FA scores had a good correlation with COI and HVAS.

CONCLUSION

This population of police working dogs has a good to excellent level of physical fitness. There was a relationship between increasing age, history of orthopedic disease, and worse scores with all questionnaires. All considered questionnaires could differentiate between animals with a previous history of orthopedic disease and sound dogs.

Platelet-Rich Plasma for the Treatment of Degenerative Lumbosacral Stenosis: A Study with Retired Working Dogs

Traditionally, canine degenerative lumbosacral stenosis (DLS) has been defined as a multifactorial syndrome characterized by lumbosacral pain triggered by the compression of the nerve rootlets of the cauda equina. There is still no consensus on the treatment of this condition, probably because there are a plethora of possible causes. In addition to compression, inflammation is a very important factor in the physiopathology of the disorder. Platelet-rich plasma (PRP) consists of an increased concentration of autologous platelets suspended in a small amount of plasma. Platelets are a source of several growth factors. Growth factors were shown to help in wound healing and biological processes, such as chemotaxis, neovascularization and synthesis of extracellular matrix, and growth factors were used to improve soft tissue healing and bone regeneration. PRP also facilitates the restoration of the structural integrity of the affected anatomy. Fourteen dogs diagnosed with DLS were treated with three epidural injections of PRP on days 0, 15 and 45. All dogs showed clinical improvement 3 months after the initial treatment. Gait was also objectively assessed by means of the use of force platform analysis before and after treatment, showing significant improvement. The results show that PRP may provide a good alternative to other nonsurgical treatments, such as prednisolone epidural injection.

Distraction Stabilization of Degenerative Lumbosacral Stenosis: Technique and Mid- to Long-Term Outcome in 30 Cases

OBJECTIVE

 To describe the dorsal laminectomy, annulectomy and distraction stabilization with pins and polymethylmethacrylate technique, its complications and outcome in the management of canine degenerative lumbosacral stenosis. To determine pre- and post-surgical foraminal width and vertebral step changes.

STUDY DESIGN

 Multi-institutional retrospective clinical study.

METHODS

 Medical records (2005-2020) of dogs treated (n = 30). Clinical signs, Modified Frankel Score, Texas Spinal Cord Injury Score, pain score (dorsal palpation of spine, tail dorsiflexion), imaging findings and complications were retrieved pre-operatively, perioperatively and at long-term follow-up.

RESULTS

 The most common presurgical imaging findings were disc protrusion (24/25) and sclerosis of the caudal end-plate of L7 (23/30). On short- to long-term assessment 18 out of 21 dogs exhibited clinical improvement and all exhibited improved pain scores (p < 0.0001). Catastrophic complications occurred in 3 dogs, and major complications occurred in 5, of which 3 required additional surgery. Mean lumbosacral step defect reduced 60% (1.8 mm ± 2.5 mm pre-surgery to 0.7mm ± 0.9mm post-surgery, p = 0.1585). Mean foraminal width significantly increased 50% long-term (3.3 mm ± 1.0 mm pre-surgery to 5.0 mm ± 0.9 mm post-surgery, p < 0.0001).

CLINICAL SIGNIFICANCE

 Dorsal laminectomy, annulectomy and distraction stabilization is a complex procedure which can significantly increase foraminal width, reduce pain and improve gait characteristics in dogs in the short- to long-term, and should be performed by surgeons experienced in lumbosacral pin placement.

Military Working Dogs: An Overview of Veterinary Care of These Formidable Assets

For the clinician treating military working dogs, an understanding of how they are sourced, preventive medicine policies, and common disease conditions is paramount in optimizing the delivery of health care. Military personnel rely heavily on the availability of these K-9s, which bring a diverse array of capabilities to myriad operational settings. Anticipating and mitigating common diseases will ensure these dogs continue to serve the needs of US military and allied forces.

Canine models of spine disorders

Neck and low back pain are common among the adult human population and impose large social and economic burdens on health care and quality of life. Spine-related disorders are also significant health concerns for canine companions with etiopathogeneses, clinical presentations, and diagnostic and therapeutic options that are very similar to their human counterparts. Historically, induced and spontaneous pathology in laboratory rodents, dogs, sheep, goats, pigs, and nonhuman primates have been used for study of human spine disorders. While each of these can serve as useful preclinical models, they all have inherent limitations. Spontaneously occurring spine disorders in dogs provide highly translatable data that overcome many of the limitations of other models and have the added benefit of contributing to veterinary healthcare as well. For this scoping review, peer-reviewed manuscripts were selected from PubMed and Google Scholar searches using keywords: "intervertebral disc," "intervertebral disc degeneration," "biomarkers," "histopathology," "canine," and "mechanism." Additional keywords such as "injury," "induced model," and "nucleus degeneration" were used to further narrow inclusion. The objectives of this review were to (a) outline similarities in key features of spine disorders between dogs and humans; (b) describe relevant canine models; and (c) highlight the applicability of these models for advancing translational research and clinical application for mechanisms of disease, diagnosis, prognosis, prevention, and treatment, with a focus on intervertebral disc degeneration. Best current evidence suggests that dogs share important anatomical, physiological, histological, and molecular components of spinal disorders in humans, such that induced and spontaneous canine models can be very effective for translational research. Taken together, the peer-reviewed literature supports numerous advantages for use of canine models for study of disorders of the spine when the potential limitations and challenges are addressed.

Qualitative and quantitative computed tomographic characteristics of the lumbosacral spine in German Shepherd military working dogs with versus without lumbosacral pain

Lumbosacral (LS) stenosis is a cause of lower back pain, loss of mission readiness, and early retirement in military working dogs (MWDs). Aims of the present two-part study were to evaluate a sample of German Shepherd MWDs using standard clinical criteria for LS pain, standard qualitative computed tomographic (CT) criteria for LS stenosis, novel quantitative CT criteria for LS stenosis, and novel behavioral classification criteria for LS pain. Data were retrieved from archives of a tertiary referral MWD hospital. Study 1 was a retrospective, observational, two-group design with a hypothesis that there would be a significant difference in the percentage of affected German Shepherd MWDs with multilevel stenosis (affecting ≥ 3 vertebrae) between LS pain groups, based on standard clinical and qualitative CT criteria. Study 2 was a retrospective, observational, cross-sectional, two- and three-group study design with a hypothesis that quantitative CT measurements would significantly differ between LS pain groups, assigned based on 3 classification systems. The 1st classification system used standard clinical criteria, while the 2nd and 3rd novel classifications included behavioral signs of LS pain. The following quantitative CT measures were recorded without knowledge of behavioral classification: vertebral foramen area, vertebral foramen volume, vertebral foramen fat area; and ratios of vertebral foramen area/vertebral body area (foramen area ratio), cranial vertebral foramen area/caudal vertebral foramen area (cranial:caudal foramen area ratio), and vertebral fat area/vertebral body area (fat area ratio). Study 1 findings did not support the hypothesis in that there was no significant difference in the percentage of dogs affected with multilevel stenosis between LS pain groups (P = 0.6567). Findings for study 2 supported the hypothesis in that dogs with LS pain were significantly more affected by multilevel stenosis (P = 0.0273). Significant differences occurred between LS pain groups in select vertebral locations for all measurements (P ≤ 0.05) except vertebral foramen area and vertebral foramen volume (P > 0.05). Comparisons using novel quantitative CT measures and behavioral classification criteria identified significant differences between LS pain groups that were not detected using standard qualitative criteria. These novel quantitative and behavioral classification criteria may be helpful in future research on causes for early retirement in German Shepherd MWDs.

Computed Tomographic Measures of Funnel-Shaped Lumbar Vertebral Canal and Articular Process Dysplasia Malformations Differ Between German Shepherd and Belgian Malinois Military Working Dogs

Researchers who study the selection and breeding program criteria for military working dogs aim to help maximize the years of active duty service. Computed tomographic (CT) quantitative phenotyping has been previously described as a method for supporting these research studies. Funnel-shaped lumbar vertebral foramen malformations have been previously described in Labrador retriever military working dogs and proposed to be risk factors for impaired arterial perfusion of nerve tissues during exercise. Articular process dysplasia malformations have been previously described in varying dog breeds and proposed to be risk factors for articular process degenerative joint disease and vertebral foramen stenosis. Aims of this retrospective, cross-sectional study were to describe quantitative CT phenotyping methods for characterizing funnel-shaped lumbar vertebral foramina and articular process dysplasia malformations and to apply these methods in a comparison between groups of German shepherd and Belgian Malinois military working dogs. A military working dog hospital's database was searched for German shepherd and Belgian Malinois dogs aged <6 years that had CT scans of the lumbosacral region during the period of 2008–2016. Observers unaware of CT findings recorded available clinical data for each of the dogs. An observer unaware of clinical data recorded CT measures of funnel-shaped lumbar vertebral foramina and articular process dysplasia malformations for each of dogs and each of the lumbar vertebrae that were available in the scans. A total of 59 dogs were sampled: 41 German shepherd and 18 Belgian Malinois. Articular process dysplasia and funnel-shaped vertebral foramen phenotypic traits were present in both breeds in this sample, with the frequency and quantitative measure of these traits being greater in German shepherd dogs and heavier dogs. Lower weight dogs had a lesser degree of a funnel-shaped foramen at all sampled vertebral locations. A consistent relationship between articular process dysplasia measures and body weight was not seen. Computed tomography measures of funnel shaped vertebral foramina were greater in German shepherd vs. Belgian Malinois dogs at the L7 vertebra (P < 0.01). The CT measures of cranial articular process dysplasia were greater in German shepherd vs. Belgian Malinois dogs at the L4 (P < 0.01) and L5 (P < 0.05) vertebrae.

Single dose epidural methylprednisolone as a treatment and predictor of outcome following subsequent decompressive surgery in degenerative lumbosacral stenosis with foraminal stenosis

Alternative treatments to surgery in canine degenerative lumbosacral stenosis (DLSS) remain limited and reliable predictors of outcome are lacking. The aims of this clinical trial were threefold: to assess the usefulness of single epidural steroid injection (ESI) in DLSS, to compare the outcomes of ESI and decompressive surgery, and evaluate ESI as a predictor of outcome following decompressive surgery. Dogs diagnosed with DLSS were prospectively recruited and administered an ESI. If clinical signs persisted or relapsed, decompressive surgery was recommended. Follow-up was obtained. Thirty-two dogs underwent ESI with 17 having subsequent surgery. Improvement after ESI was seen in 27/32 dogs (84.4%), with 17/22 (77.2%) relapsing within 6 months (n = 15/17 relapsing within 2 months). Five dogs failed to respond to ESI and another five (15.6%) presented a persistent post-ESI favourable response (mean follow-up time, 9.4 months). Post-surgical improvement occurred in all dogs. Outcome appeared more favourable following surgical decompression, with a trend towards reduced pain, increased mobility, and greater quality of life score. This study was unable to demonstrate that ESI could predict surgical outcome. ESI was confirmed as an effective treatment in most but not all cases, leading to transient alleviation of clinical signs for longer than previously reported. ESI provided a complete and apparently long-term sustained resolution of clinical signs in a subset of dogs. Despite this, there was indication that surgical decompression can lead to a more favourable outcome. Epidural steroid injection has a role in the management of DLSS dogs, particularly when surgery is not an option.

Pain and Problem Behavior in Cats and Dogs

We argue that there is currently an under-reporting of the ways in which pain can be associated with problem behavior, which is seriously limiting the recognition of this welfare problem. A review of the caseloads of 100 recent dog cases of several authors indicates that a conservative estimate of around a third of referred cases involve some form of painful condition, and in some instances, the figure may be nearly 80%. The relationship is often complex but always logical. Musculoskeletal but also painful gastro-intestinal and dermatological conditions are commonly recognized as significant to the animal's problem behavior. The potential importance of clinical abnormalities such as an unusual gait or unexplained behavioral signs should not be dismissed by clinicians in general practice, even when they are common within a given breed. In general, it is argued that clinicians should err on the side of caution when there is a suspicion that a patient could be in pain by carefully evaluating the patient's response to trial analgesia, even if a specific physical lesion has not been identified.

The effects of foraminotomy and intervertebral distraction on the volume of the lumbosacral intervertebral neurovascular foramen: An ex vivo study

Degenerative lumbosacral stenosis in dogs frequently involves L7-S1 foraminal stenosis and L7 nerve root compression. Surgical techniques to decompress the L7 nerve root include foraminotomy and intervertebral distraction. The objective of this study was to compare the effect of foraminotomy and intervertebral distraction on the total, cranial, and caudal compartmental volumes of the L7-S1 intervertebral neurovascular foramen (NF). CT images were obtained from eight canine lumbosacral (L5-CD1) specimens in the following sequential conditions: native spine (1), after dorsal laminectomy and partial discectomy of L7-S1 (2), after L7-S1 foraminotomy (3), after distraction with an interbody cage between L7 and S1 (4), after cage distraction stabilized with pedicle screw-rod fixation in neutral (5) and flexed position (6). The volume of the complete NF and its cranial and caudal subcompartments were calculated using the CT images and statistically compared between conditions. P < 0.05 was considered statistically significant. The volume of the complete NF was significantly increased after foraminotomy (mean ± standard deviation (146.8 ± 26.5%, P < 0.01) and after distraction (Condition 4, 121.0 ± 19.1%; Condition 5, 116.6 ± 29.3 %; Condition 6, 119.0 ± 21.8 %; P = 0.01) with no difference between the distraction conditions. Foraminotomy induced a significantly larger increase in total NF volume compared to distraction. Foraminotomy, but not distraction, induced a significant increase in volume of the cranial subcompartment (158.2 ± 33.2 %; P < 0.01). Foraminotomy is more effective in increasing the foraminal volume and especially the cranial subcompartment, which is where the L7 nerve root traverses the NF. Hence, foraminotomy may be more effective in decompressing the L7 nerve root.

Canine Degenerative Lumbosacral Stenosis: Prevalence, Impact And Management Strategies

Canine degenerative lumbosacral stenosis (DLSS) is a syndrome of low back pain with or without neurologic dysfunction associated with compression of the cauda equina. Most commonly occurring in medium- to large-breed dogs of middle to older age, German shepherd and working dogs are predisposed. Diagnosis is based on a combination of clinical signs, advanced imaging and ruling out other differential diagnoses. The volume of the intervertebral foramina at the lumbosacral junction is naturally reduced on extension but degenerative changes lead to a more marked reduction that can impinge the L7 nerve roots. Evidence is lacking on which to base decision-making for treatment of dogs with DLSS. However, surgical intervention may be indicated in dogs that do not respond to conservative management, or for dogs in which there is a requirement to work that prevents lifestyle adjustments. Improvements in electrodiagnosis and novel intra-discal treatments may improve the management of DLSS in the future.

CT and gross pathology are comparable methods for detecting some degenerative sacroiliac joint lesions in dogs

Degenerative sacroiliac joint disease is a cause of lumbosacral pain in dogs; however, published information on cross-sectional imaging characteristics is limited. Objectives of this retrospective, secondary analysis, methods-comparison study were to test hypotheses that CT lesions reported in humans with degenerative sacroiliac joint disease are also present in dogs, and that CT is comparable to gross pathology for detecting these lesions. Matched CT and gross pathology slice images of 30 sacroiliac joints were retrieved from a previous prospective, canine cadaver study. A veterinary radiologist interpreted randomized CT images for each joint based on previously published CT characteristics of lesions in humans with degenerative sacroiliac joint disease. A veterinary pathologist independently interpreted randomized gross pathology images using the same criteria. All joints had at least one CT lesion consistent with degenerative sacroiliac joint disease. A new CT lesion was also identified and termed "subarticular cleft." The CT and gross pathology methods agreed for detecting joints with subchondral sclerosis, subchondral erosion, and intra-articular ankylosis lesions (P > .05, McNemar's test), but disagreed for detection of joints with subchondral cyst, para-articular ankylosis, and subarticular cleft lesions (P ≤ .05). Using gross pathology as the reference standard, CT had 100% sensitivity for detection of subarticular cleft and subchondral cyst lesions, with 56% and 22% specificity, respectively. Para-articular ankylosis lesions were detected by CT but not by gross pathology. Findings supported the hypothesis that CT lesions reported in humans with degenerative sacroiliac joint disease are also present in dogs, and partially supported the hypothesis that CT is comparable to gross pathology for detecting joints with these lesions.

CT measures of lumbosacral paraspinal muscle size are not correlated with CT measures of lumbosacral stability in military working Labrador Retrievers

Management of degenerative lumbosacral stenosis in military working dogs more frequently utilizes core conditioning exercise programs. Future research on the effectiveness of these programs may benefit from an improved understanding of relationships between paraspinal muscle size and lumbosacral stability. The aim of this retrospective, secondary analysis, cross-sectional study was to test the following hypotheses related to CT measures: (a) transverse paraspinal muscle area ratios differ between hip flexion and extension, (b) lumbosacral angle and lumbosacral range of motion differ by lumbosacral angle measurement technique, and (c) transverse paraspinal muscle area ratios are correlated with CT measures of lumbosacral stability (parasagittal and parasagittal oblique foraminal area changes) regardless of hip position and with lumbosacral range of motion within each hip position. Lumbosacral CT scans in hip flexion and extension were retrieved from a previous prospective study of military working Labrador Retrievers. A single observer performed triplicate measurements of transverse paraspinal muscle area ratios, parasagittal foraminal area, and parasagittal oblique foraminal area for each hip position and another observer independently performed triplicate measurements of lumbosacral angle and lumbosacral range of motion at L7-S1 using two published techniques. Thirty-nine dogs were analyzed and significant differences were identified between hip flexion and extension for all mean transverse paraspinal muscle area ratio values (P ≤ .05). Mean lumbosacral angles also significantly differed between the published techniques in both hip flexion and extension. When comparing mean lumbosacral range of motion values, one of the published techniques produced significantly smaller values. No significant correlation was found between transverse paraspinal muscle area ratios and parasagittal foraminal area changes, parasagittal oblique foraminal area changes, or lumbosacral range of motion. These results should be considered when designing studies using these CT measures in military working dogs.

Survey of Handlers of 158 Police Dogs in New Zealand: Functional Assessment and Canine Orthopedic Index

Objectives: To determine the functional assessment (FA) of fitness and Canine Orthopedic Index (COI) scores of 158 police dogs. The hypothesis was the dogs would have excellent fitness and no evidence of orthopedic disease regardless of age as reported by the handlers. Study Design:Observational, prospective study. Sample Population: Handlers of dogs >1 year of age in active duty or breeding/active duty. Methods: COI and FA questionnaires were completed via e-mail. Fisher's Exact test for count data assessed scores by age group (<2 years, 2-5 years, >5 years); Wilcoxon Signed-rank test correlated COI parameters (stiffness, function, gait, quality of life) to FA. Results: The dogs were 3.2 ± 2.4 (mean ± standard deviation) years-old, 96% were German Shepherds and 111 were male. 32% of dogs could hold the "Hup" position for no longer than 4 s and 8% frequently had difficulty with this task. Difficulty jumping into vehicles occurred in 1/3 of the dogs. Overall FA was impaired in 20% (score >8), abnormal in 15% (score = 5-7), and reduced (score = 1-4) in 36% of dogs. Only 29% had normal function (FA score = 0) and these were significantly younger (2.8 ± 1.7 years, p < 0.05) than impaired dogs (6.6 ± 2.2 years). COI stiffness score was abnormal in 37% (3.3 ± 2.2) and gait was abnormal in 41% (5.4 ± 4.0). Quality of life (QOL) was excellent in 69% of dogs. Stiffness for the <2 year-old group was 0.2 ± 0.8, for the 2-5 year-old group was 1.1 ± 2.0 and for the >5 year-old group was 3.2 ± 2.4. Gait score for the <2 year group was 0.8 ± 2.2, and for the 2-5 year group was 1.9 ± 3.2 and for the >5 year group was 6.0 ± 4.3. Quality of life was close to excellent for the <2 year-olds (0.3 ± 1.1) and 2-5 year-olds (0.8 ± 2.0) but the >5 year-olds scored higher (3.0 ± 2.5). Only the COI gait score correlated with the FA score (p = 0.30). Conclusions and Clinical Relevance: Police dogs were reported by handlers to have good to excellent QOL, however, increasing age was associated with declining FA and COI scores.

Cauda equina syndrome in dogs - a review

A lesion of sacrococcygeal spinal nerve roots forming a structure that resembles a horse's tail results in the development of clinical entity identified as the cauda equina syndrome (CES). The disease can evolve slowly and symptomatology can be incomplete, but the fully developed CES is characterized by pain and altered sensation in the pelvic extremities, tail, perianogenital region, paresis or plegia of hind limbs, incontinence and impotence. Major causes of CES in dogs are degenerative changes of the lumbosacral vertebral column, haematoma, inflammation, neoplasm or trauma. The diagnosis is based on history, clinical presentation, neurological symptomatology, spinal röntgenography, computed tomography, and magnetic resonance imaging. In animals experiencing initial episodes of CES, conservative therapy can be attempted. But the only rational treatment of patients with severe neurological deficit is surgical decompression of the neural structures. The outcome depends on the underlying aetiology and the degree of sensory, motor and autonomic dysfunction. Canine and porcine experimental models mimicking the CES showed the involvement of intrinsic spinal cord structures. This points out the need for an early diagnosis followed by aggressive management before irreversible neuronal lesions develop. The search strategy involved the PubMed, Medline, Embase and ISI Web of Science from January 2000 to August 2017 using the terms 'cauda equina syndrome' and 'lumbosacral stenosis' in the English language literature; also references from selected papers were scanned and relevant articles included.

Long-term outcome following lateral foraminotomy as treatment for canine degenerative lumbosacral stenosis

Lateral foraminotomy has been described as an effective surgical treatment for foraminal stenosis in the treatment of degenerative lumbosacral stenosis (DLSS) in dogs. Clinical records were reviewed from 45 dogs which had undergone lateral foraminotomy at the lumbosacral junction either alone or in combination with decompressive midline dorsal laminectomy. Short-term outcome at six weeks was assessed by the surgeon to be good (11.1 per cent) or excellent (88.9 per cent) in all 45 cases. Long-term outcome beyond six months for lumbosacral syndrome was assessed by the owner as excellent in all 34 cases for which follow-up was available despite recurrence in five cases. Recurrence of clinical signs was not related to re-establishment of foraminal compression at the surgical site when assessed on repeat MRI and was managed by either contralateral foraminotomy in one case or conservative management with excellent response. This study confirms lateral foraminotomy as an effective procedure in the management of DLSS-affected dogs suffering from foraminal stenosis and demonstrates that initial good short-term results are maintained long term despite some treatable recurrences. Lateral foraminotomy is an effective procedure when used appropriately in DLSS with foraminal stenosis either alone or in combination with midline dorsal laminectomy.

Evaluation of the rostral projection of the sacral lamina as a component of degenerative lumbosacral stenosis in German shepherd dogs

OBJECTIVE

To determine the association between a greater rostral projection of the sacral lamina and clinical signs of cauda equina syndrome (CES) in German shepherd dogs (GSD) with presumptive degenerative lumbosacral disease (DLSS).

STUDY DESIGN

Retrospective cohort study.

SAMPLE POPULATION

One hundred forty-three GSD (125 police dogs and 18 pet dogs) presenting for either CES or prebreeding evaluation. Fifty-five were classified as affected by CES and diagnosed with DLSS, and 88 were classified as unaffected on the basis of clinical and imaging findings.

METHODS

The position of the rostral edge of the sacral lamina was measured from radiographs and/or computed tomography (CT) scans. This position was compared between affected and unaffected dogs. In dogs that underwent both radiography and CT scanning, the agreement between sacral lamina localization using each imaging modality was determined. Owners/handlers were contacted to determine whether dogs subsequently developed clinical signs compatible with CES at a mean of 29 months (unaffected).

RESULTS

The sacral lamina did not extend as far rostrally in affected dogs, compared to unaffected dogs (P = .04). Among the 88 dogs unaffected by CES at initial evaluation, 2 developed clinical signs consistent with CES at follow-up.

CONCLUSION

Rostral projection of the sacral lamina, previously proposed as a potential risk factor in dogs with CES due to lumbosacral degeneration, was not associated with a diagnosis of DLSS in this study; the opposite was true.

CLINICAL SIGNIFICANCE

Rostral projection of the sacral lamina may not be a predisposing factor in the development of CES due to DLSS in GSD.

Traumatic L7 articular processes fracture and spondylolisthesis following dorsal lumbosacral laminectomy in a cat

Case summary

A 12-year-old neutered male domestic shorthair cat was presented to our referral hospital with a chronic history of tenesmus and lumbosacral pain. A diagnosis of degenerative lumbosacral stenosis (DLSS) was made and a standard dorsal L7–S1 laminectomy was performed uneventfully, with complete recovery within 1 month. The cat was brought back 4 months later for investigation of lumbosacral pain after having suffered a minor traumatic event. Neurological examination identified a low tail carriage, weakness, exercise intolerance, left pelvic limb lameness and diminished withdrawal reflexes in both pelvic limbs with severe sacrocaudal pain. A traumatic facet fracture of the L7 articular processes and subsequent spondylolisthesis was diagnosed. A second surgery was performed to stabilise the region. The cat was normal on neurological examination 1 month later and no further clinical signs were noted.

Relevance and novel information

This is the first description of a fracture and spondylolisthesis as a possible postoperative complication after L7–S1 dorsal laminectomy in a cat. The case highlights the importance of postoperative changes in the supportive structures of the lumbosacral spine in cats after surgical treatment of DLSS.

Lumbosacral stenosis in Labrador retriever military working dogs - an exomic exploratory study

Background

Canine lumbosacral stenosis is defined as narrowing of the caudal lumbar and/or sacral vertebral canal. A risk factor for neurologic problems in many large sized breeds, lumbosacral stenosis can also cause early retirement in Labrador retriever military working dogs. Though vital for conservative management of the condition, early detection is complicated by the ambiguous nature of clinical signs of lumbosacral stenosis in stoic and high-drive Labrador retriever military working dogs. Though clinical diagnoses of lumbosacral stenosis using CT imaging are standard, they are usually not performed unless dogs present with clinical symptoms. Understanding the underlying genomic mechanisms would be beneficial in developing early detection methods for lumbosacral stenosis, which could prevent premature retirement in working dogs. The exomes of 8 young Labrador retriever military working dogs (4 affected and 4 unaffected by lumbosacral stenosis, phenotypically selected by CT image analyses from 40 dogs with no reported clinical signs of the condition) were sequenced to identify and annotate exonic variants between dogs negative and positive for lumbosacral stenosis.

Results

Two-hundred and fifty-two variants were detected to be homozygous for the wild allele and either homozygous or heterozygous for the variant allele. Seventeen non-disruptive variants were detected that could affect protein effectiveness in 7 annotated (SCN1B, RGS9BP, ASXL3, TTR, LRRC16B, PTPRO, ZBBX) and 3 predicted genes (EEF1A1, DNAJA1, ZFX). No exonic variants were detected in any of the canine orthologues for human lumbar spinal stenosis candidate genes.

Conclusions

TTR (transthyretin) gene could be a possible candidate for lumbosacral stenosis in Labrador retrievers based on previous human studies that have reported an association between human lumbar spinal stenosis and transthyretin protein amyloidosis. Other genes identified with exonic variants in this study but with no known published association with lumbosacral stenosis and/or lumbar spinal stenosis could also be candidate genes for future canine lumbosacral stenosis studies but their roles remain currently unknown. Human lumbar spinal stenosis candidate genes also cannot be ruled out as lumbosacral stenosis candidate genes. More definitive genetic investigations of this condition are needed before any genetic test for lumbosacral stenosis in Labrador retriever can be developed.

Electronic supplementary material

The online version of this article (10.1186/s40575-017-0052-6) contains supplementary material, which is available to authorized users.

Phenotyping of lumbosacral stenosis in Labrador retrievers using computed tomography

Deep phenotyping tools for characterizing preclinical morphological conditions are important for supporting genetic research studies. Objectives of this retrospective, cross-sectional, methods comparison study were to describe and compare qualitative and quantitative deep phenotypic characteristics of lumbosacral stenosis in Labrador retrievers using computed tomography (CT). Lumbosacral CT scans and medical records were retrieved from data archives at three veterinary hospitals. Using previously published qualitative CT diagnostic criteria, a board-certified veterinary radiologist assigned dogs as either lumbosacral stenosis positive or lumbosacral stenosis negative at six vertebral locations. A second observer independently measured vertebral canal area, vertebral fat area, and vertebral body area; and calculated ratios of vertebral canal area/vertebral body area and vertebral fat area/vertebral body area (fat area ratio) at all six locations. Twenty-five dogs were sampled (lumbosacral stenosis negative, 11 dogs; lumbosacral stenosis positive, 14 dogs). Of the six locations, cranial L6 was the most affected by lumbosacral stenosis (33%). Five of six dogs (83%) with clinical signs of lumbosacral pain were lumbosacral stenosis positive at two or more levels. All four quantitative variables were significantly smaller at the cranial aspects of the L6 and L7 vertebral foramina than at the caudal aspects (P < 0.0001). Fat area ratio was a significant predictor of lumbosacral stenosis positive status at all six locations with cranial L6 having the greatest predictive value (R² = 0.43) and range of predictive probability (25-90%). Findings from the current study supported the use of CT as a deep phenotyping tool for future research studies of lumbosacral stenosis in Labrador retrievers.

Feasibility for Measuring Transverse Area Ratios and Asymmetry of Lumbosacral Region Paraspinal Muscles in Working Dogs Using Computed Tomography

OBJECTIVES

Describe computed tomographic (CT) anatomy of canine lumbosacral (LS) paraspinal muscles, a method for measuring paraspinal muscle transverse area ratios and asymmetry using CT, and application of this method in a small sample of working dogs with versus without LS pain.

METHODS

Published anatomy references and atlases were reviewed and discrepancies were resolved by examination of anatomic specimens and multiplanar reformatted images to describe transverse CT anatomy of LS region paraspinal muscles. Sixteen Belgian malinois military working dogs were retrospectively recruited and assigned to LS pain positive versus negative groups based on medical record entries. A single observer unaware of dog group measured CT transverse areas of paraspinal muscles and adjacent vertebral bodies, in triplicate, for L5-S1 vertebral locations. A statistician compared muscle transverse area ratios and asymmetry at each vertebral location between groups.

RESULTS

The relative coefficient of variation for triplicate CT area measurements averaged 2.15% (N = 16). Multifidus lumborum (L6-7), psoas/iliopsoas (L5-6, L6-7), and sacrocaudalis dorsalis lateralis (L6-7, L7-S1) transverse area ratios were significantly smaller in dogs with LS pain (n = 11) versus without LS pain (n = 5) (p ≤ 0.05). Muscle asymmetry values were not significantly greater in dogs with versus without LS pain.

CLINICAL RELEVANCE

Computed tomographic morphometry of LS region paraspinal muscles is a feasible objective method for use in future evidence-based research studies in working dogs. Potential future research applications include determining whether decreased paraspinal muscle area ratios and/or increased paraspinal muscle asymmetry could be used as markers for preclinical LS pain in stoic dogs or risk factors for other injuries in high performance canine athletes, or determining whether core muscle strengthening exercise prescriptions for dogs with LS pain have an effect on paraspinal muscle area ratios and asymmetry.

Lumbar paraspinal muscle transverse area and symmetry in dogs with and without degenerative lumbosacral stenosis

OBJECTIVES

To investigate whether dogs with degenerative lumbosacral stenosis have decreased lumbar paraspinal muscle transverse area and symmetry compared with control dogs.

MATERIALS AND METHODS

Retrospective cross-sectional study comparing muscles in transverse T2-weighted magnetic resonance images for nine dogs with and nine dogs without degenerative -lumbosacral stenosis. Mean transverse area was measured for the lumbar multifidus and sacrocaudalis dorsalis lateralis muscles bilaterally and the L7 vertebral body at the level of the caudal endplate. Transverse areas of both muscle groups relative to L7 and asymmetry indices were compared between study populations using independent t tests.

RESULTS

Mean muscle-to-L7 transverse area ratios were significantly smaller in the degenerative lumbosacral stenosis group compared with those in the control group in both lumbar multifidus (0·84 ±0·26 versus 1·09 ±0·25; P=0·027) and sacrocaudalis dorsalis lateralis (0·5 ±0·15 versus 0·68 ±0·12; P=0·005) muscles. Mean asymmetry indices were higher for both muscles in the group with degenerative lumbosacral stenosis than in the control group, but highly variable and the difference was not statistically significant.

CLINICAL SIGNIFICANCE

These findings suggest that dogs with degenerative lumbosacral stenosis have decreased lumbar paraspinal muscle mass that may be a cause or consequence of the -syndrome. Understanding altered paraspinal muscle characteristics may improve understanding of the -pathophysiology and management options for degenerative lumbosacral stenosis.

Ventral surgical approach to the lumbosacral joint in the dog

OBJECTIVE

To describe a ventral surgical approach to the lumbosacral (LS) junction, access to L7 and S1, and access to the LS disc.

STUDY DESIGN

Cadaveric descriptive study.

ANIMALS

Canine cadavers (n = 6).

METHODS

A ventral surgical approach to the LS junction was made and local anatomic structures documented. Accessible ventral L7 and S1 vertebral bodies and LS disc were marked with India ink. Total and marked surface areas were calculated. The potential for bicortical and unicortical implant placement was determined in transverse slices of L7 and S1. Exposed ventral disc annulus relative to vertebral canal diameters were measured.

RESULTS

Portions of L7 and S1 were accessible in all dogs, but shape and dimensions varied. Ventral access for implant placement was available in both L7 and S1 in every dog. The median sacral artery and vein were in contact with the ventral LS disc annulus in every dog. Accessible ventral annulus were greater than vertebral canal in all dogs.

CONCLUSIONS

Ventral approach to the LS junction is possible, with LS discectomy, and implant placement in L7 and S1 vertebral bodies possible from this approach. Injury to, or sacrifice of, the median sacral artery and/or vein may occur in this approach.

Management of degenerative lumbosacral disease in cats by dorsal laminectomy and lumbosacral stabilization

In this case series we describe the diagnosis and surgical treatment of five cats affected by clinical cauda equina syndrome as a result of degenerative lumbosacral stenosis. Radiographic and magnetic resonance imaging findings confirmed the suspected diagnosis of disc-associated lumbosacral disease. Cauda equina decompression was achieved by dorsal laminectomy followed by dorsal annulectomy and nuclear extirpation. Dorsal stabilization was achieved using miniature positive-profile pins inserted into the vertebral body of L7 and the wings of S1 with the free ends of the pins being embedded in a bolus of gentamicin-impregnated polymethylmethacrylate. Reassessment two years postoperatively using a previously validated feline specific owner questionnaire indicated satisfactory outcome with complete return to normal activity and resolution of signs of pain in all cases.

Transarticular facet screw stabilization and dorsal laminectomy in 26 dogs with degenerative lumbosacral stenosis with instability

OBJECTIVE

To describe outcome after transarticular facet screw stabilization and dorsal laminectomy for treatment of dynamic degenerative lumbosacral stenosis (DLS) in 26 dogs.

STUDY DESIGN

Retrospective case series.

ANIMALS

Dogs (n = 26) with dynamic DLS.

METHODS

Medical records (2004-2009) of dogs treated with transarticular facet screw stabilization and dorsal laminectomy were reviewed. Dogs (n = 26) were available for immediate postoperative follow-up, 21 dogs at 6 weeks, and 15 at greater than 6 months. Dogs were evaluated by radiographic assessment and owner questionnaire. Lumbosacral (LS) intervertebral disc (IVD) spaces were measured on pre and postoperative 6-week and 6-month radiographs.

RESULTS

In 23 dogs, improvement in clinical signs occurred within 7 days of surgery. Overall postsurgical complication rate directly related to the surgical procedure was 15.4%. LS IVD space measurements taken immediately postoperatively, at 6 weeks, and ≥ 6 months were all significantly increased compared with preoperative measurements. All working dogs (4) returned to full work within 14 months. Most owners (85%) reported their dog was ambulating normally at 6 months with no perceptible lameness during normal activity. All owners perceived their dog's ability to walk, run, and jump after surgery to be improved.

CONCLUSIONS

Transarticular facet screw stabilization and dorsal laminectomy maintains distraction of the LS IVD space for medium-to-large breed dogs with dynamic DLS with a high degree of owner satisfaction, and is comparable to other reported surgical techniques for DLS.

Feasibility and accuracy of ultrasound-guided sacroiliac joint injection in dogs

Frozen cadaver specimens from three dogs were used to create a sectional anatomic atlas of the sacroiliac region. Frozen/thawed cadaver specimens from 12 dogs were used to develop an ultrasound-guided sacroiliac joint injection technique. Accuracy of the technique was tested in 15 additional canine cadaver specimens, using injectate containing blue dye and iodinated contrast medium. Sonoanatomic landmarks for consistently identifying a caudodorsal window into the canine sacroiliac joint space included the L7-S1 articular process joints, ilial wing, sacral wing, sacral lamina, and median sacral crest. Accuracy of ultrasound-guided sacroiliac joint injection was not significantly affected by operator, but was affected by the tissue location targeted and the reference standard used for calculations. Accuracy of the technique was good for placing injectate into either the synchondrosis component, dorsal sacroiliac ligament or ventral sacroiliac ligament; fair to poor for placing injectate into the synovial component; and poor for placing injectate into all four sacroiliac soft tissue structures. Concurrent placement of injectate into extraarticular tissues occurred frequently. We conclude that ultrasound-guided sacroiliac joint injection is feasible for evaluation as a treatment method for lumbosacral region pain in dogs, but is not sufficiently accurate for localizing pain to the sacroiliac joint alone.

MR-imaging of lumbosacral intervertebral disc degeneration in clinically sound German shepherd dogs compared to other breeds

German shepherd dogs are overrepresented in the group of dogs with cauda equina compression syndrome due to degenerative lumbosacral stenosis. A congenital predisposition for early degeneration of the lumbosacral intervertebral disc has been suspected. Our aims were to assess the morphologic appearance of the lumbosacral intervertebral disc and the lumbosacral junction in healthy German shepherd dogs compared to other breeds and to evaluate for an early onset of degenerative changes. The lumbosacral spine of 110 clinically sound German shepherd dogs and 47 healthy dogs of other large breeds was examined using magnetic resonance (MR) imaging. The degeneration of every intervertebral disc was graded using an established classification system. Signal intensity of the entire lumbosacral disc and the nucleus pulposus was determined independently. Lumbosacral malalignment was assessed according to a previously described method. The findings for the German shepherd dogs were compared to those of the other breeds. Although most dogs were younger than 18 months at the date of examination, significantly higher grades of degeneration were detected for the lumbosacral intervertebral disc of German shepherd dogs (P < 0.003). Degeneration of the lumbosacral intervertebral disc was independent from findings in the other lumbar discs. We conclude that the German shepherd dog has a predisposition for degenerative changes in the lumbosacral intervertebral disc.

Assessment of Decompressive Surgery in Dogs with Degenerative Lumbosacral Stenosis Using Force Plate Analysis and Questionnaires

OBJECTIVE

To evaluate the long-term outcome after decompressive surgery in dogs with degenerative lumbosacral stenosis (DLS), using force plate analysis (FPA) and owner questionnaires.

STUDY DESIGN

Prospective clinical study.

ANIMALS

Dogs with DLS (n=31) and 24 clinically normal Labrador Retrievers.

METHODS

FPA was performed before surgery (31 dogs) and at 3 days, 6 weeks, 6 months (each, 31 dogs) and >or=1.5 years (12 dogs) after surgery. Peak vertical forces (Fz(+)), braking (Fy(+)), and propulsive forces (Fy(-)), and the corresponding impulses were determined. Questionnaires were completed by the owners before and at 6 months and >or=1.5 years after surgery.

RESULTS

Fy(-) of the pelvic limbs and the ratio pelvic/thoracic of Fy(-) (P/TFy(-)) were significantly smaller in dogs with DLS than controls. Fy(-) and P/TFy(-) decreased significantly 3 days after surgery, and increased during 6 months follow-up, but with long-term follow-up the values remained the same and were smaller than controls. From questionnaires there was a significant improvement after surgery compared with function before surgery. Most owners were satisfied with outcome after surgery.

CONCLUSIONS

Propulsive forces of the pelvic limbs in dogs with DLS are impaired and are partially restored by decompressive surgery.

CLINICAL RELEVANCE

Owner's questionnaires illustrate that decompressive surgery restores function as perceived by owners whereas FPA continues to show impaired propulsive forces for the pelvic limbs.

Force plate analysis before and after dorsal decompression for treatment of degenerative lumbosacral stenosis in dogs

OBJECTIVE

Using force plate analysis (FPA), determine ground reaction forces in dogs with degenerative lumbosacral stenosis (DLS) and evaluate the effects of lumbosacral decompressive surgery.

STUDY DESIGN

Prospective clinical study.

ANIMALS

Twelve dogs with DLS.

METHODS

DLS was diagnosed by clinical signs, radiography, computed tomography, and/or magnetic resonance imaging. FPA was performed before surgery, and 3 days, 6 weeks, and 6 months after surgery. The mean peak braking (Fy+), peak propulsive (Fy-), and peak vertical (Fz+) forces of 8 consecutive strides were determined. The ratio between the total Fy- of the pelvic limbs and the total Fy- of the thoracic limbs (P/TFy-), reflecting the distribution of Fy-, was analyzed to evaluate any changes in locomotion pattern postoperatively. Ground reaction force data for DLS dogs were compared with data derived from 24 healthy dogs (control).

RESULTS

In dogs with DLS, the propulsive forces (Fy-) of the pelvic limbs were significantly smaller than those of controls. P/TFy- was significantly smaller in dogs with DLS than in control dogs, and increased during the follow-up period, reaching normal values 6 months after surgery.

CONCLUSIONS

Cauda equina compression in dogs with DLS decreases the propulsive force of the pelvic limbs and surgical treatment restores the propulsive force of the pelvic limbs in a 6-month period.

CLINICAL RELEVANCE

In dogs with DLS, FPA is an effective method in evaluating the response to surgical treatment. Normal propulsive force in the pelvic limbs was restored during 6 months after decompressive surgery.

The lumbosacral junction in working german shepherd dogs -- neurological and radiological evaluation

The clinical and radiological incidence of lumbosacral (LS) disease was studied on 57 German Shepherd dogs (GSDs) used in active service. The study included a clinical history, a neurological examination, and plain radiographs of the caudal lumbar vertebrae. The neurological examinations revealed lower back pain and/or neural deficits in 21 dogs, of which 14 had a history of pain or pelvic gait abnormalities. Radiographic findings were spondylosis at L7-S1, degeneration of L7-S1 disc, LS malalignment, transitional LS vertebrae and/or primary spinal canal stenosis in 15 dogs with neurological abnormalities and/or back pain and in 18 dogs with no clinical signs. No correlation between the neurological and the radiographic findings were found. This study demonstrates that even prominent radiographic LS abnormalities are of minimal value in the evaluation of LS disease in the GSD.

Three-dimensional motion pattern of the caudal lumbar and lumbosacral portions of the vertebral column of dogs

OBJECTIVE

To evaluate the 3-dimensional motion pattern including main and coupled motions of the caudal lumbar and lumbosacral portions of the vertebral column of dogs.

ANIMALS

Vertebral columns of 9 German Shepherd Dogs (GSDs) and 16 dogs of other breeds with similar body weights and body conditions.

PROCEDURE

Main and coupled motions of the caudal lumbar and lumbosacral portions of the vertebral column (L4 to S1) were determined by use of a testing apparatus that permitted precise application of known pure moments to the vertebral column. Motion was compared between GSDs and dogs of other breeds.

RESULTS

All specimens had a similar motion pattern consisting of main motion and a certain amount of coupled motion including translation. Vertebral columns of GSDs had significantly less main motion in all directions than that of dogs of other breeds. Translation was similar in GSDs and dogs of other breeds and was smallest at the lumbosacral motion segment.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that motion in the caudal lumbar and lumbosacral portions of the vertebral column of dogs is complex and provided a basis for further studies evaluating abnormal vertebral columns.