Prevalence of Spondylosis Deformans in Tailed Versus Tail-Docked Rottweilers.

Tail docking is a routine procedure for rottweilers in the United States and Canada. A cross-sectional comparative study was conducted in tailed (n = 25) and docked (n = 39) rottweilers ≥5 yr old to compare prevalence and severity of spondylosis deformans in the lumbar spine between groups. The prevalence of spondylosis was 68.0% in tailed dogs and 76.9% in docked dogs, which was not significantly different (P = .563). Distribution of spondylosis severity did not significantly differ between tailed and docked dogs (P = .102). Logistic regression found moderate to severe spondylosis was associated with age and sex. Females were three times at greater risk than males (odds ratio 3.10, 95% confidence interval 1.060-9.08; P = .039). Risk increased 1.4 times for each additional year (odds ratio 1.43, 95% confidence interval 1.02-1.99, P = .036). Tail docking may not impact or only play a minor role in spondylosis deformans in rottweilers.

Pathology in skeletons of Peale's dolphin Lagenorhynchus australis from southern South America.

Peale's dolphin Lagenorhynchus australis is frequently seen off the coast of southern South America, where it feeds among coastal kelp beds and occasionally strands. We searched for macroscopic evidence of skeletal lesions in 78 specimens of Peale's dolphin from 2 museum collections, which contain almost all of the species' skeletons known in collections worldwide. Thirty-two specimens (41%) had some type of osteological abnormalities. In 21 cases (66%), congenital deformations were the most predominant abnormality found. Acquired lesions included (1) induced trauma: abnormal curvature (n=5 specimens) and fractures (n=2); (2) infectious diseases: spondylo-osteomyelitis (n=3); and (3) degenerative diseases: exostoses (n=8) and spondylosis deformans (n=4). It is noteworthy that all of these animals died incidentally in gillnet entanglement and were presumably healthy at the time of death. The effect that different osseous lesions may have on an animal's quality of life may depend on the area of the spine affected and the number of vertebrae involved.

Cervical Distraction-Stabilization Using an Intervertebral Spacer Screw and String-of Pearl (SOP™) Plates in 16 Dogs With Disc-Associated Wobbler Syndrome.

OBJECTIVE: To retrospectively investigate a novel surgical technique using the Fitz Intervertebral Traction Screw (FITS) combined with string-of-pearl (SOP™) locking plates for the treatment of Disc Associated Wobbler Syndrome (DAWS). STUDY DESIGN: Case series (n = 16). METHODS: Ventral approach and fenestration of the affected disc(s), nuclear extirpation, and insertion of the FITS device to the level of the dorsal annulus was followed by application of one or two 3.5 mm SOP™ plates. Autogenous cancellous bone graft was placed between adjacent vertebrae. Long-term followup (>12months) via telephone or examination was attempted for all dogs. RESULTS: Case records of 16 dogs were reviewed. All dogs had Type II disc disease with a single site in 13 dogs and multiple sites in 3 dogs. Mean ± SD age was 75 ± 38 months and body weight was 34 ± 7 kg. Fifteen of the 16 dogs had significantly improved neurologic status (P =.01) at 6 weeks. Seven of the 16 dogs were examined at 24-36 months with 6 considered normal and 1 had mild ataxia. Postoperative radiographic intervertebral distraction was significant (P = .01). Radiographic bridging was recorded in 10/16 dogs at 6 weeks and in 7 dogs available for follow-up at 5-36 months. Computed tomography in 3 dogs at 24-36 months and postmortem with histology in 1 dog confirmed bone-bridging. Complications were not considered clinically significant and included implant loosening (2 dogs, both single plates) and minor end-plate subsidence (8 dogs). CONCLUSION: Application of the FITS device in combination with 2 ventral SOP™ locking plates and autogenous cancellous bone graft was associated with excellent outcomes in dogs treated for DAWS in this small case series.

Feasibility of ultrasound-guided epidural access at the lumbo-sacral space in dogs.

Epidural injections are commonly performed blindly in veterinary medicine. The aims of this study were to describe the lumbosacral ultrasonographic anatomy and to assess the feasibility of an ultrasound-guided epidural injection technique in dogs. A cross sectional anatomic atlas of the lumbosacral region and ex vivo ultrasound images were obtained in two cadavers to describe the ultrasound anatomy and to identify the landmarks. Sixteen normal weight canine cadavers were used to establish two variations of the technique for direct ultrasound-guided injection, using spinal needles or epidural catheters. The technique was finally performed in two normal weight cadavers, in two overweight cadavers and in five live dogs with radiographic abnormalities resulting of the lumbosacral spine. Contrast medium was injected and CT was used to assess the success of the injection. The anatomic landmarks to carry out the procedure were the seventh lumbar vertebra, the iliac wings, and the first sacral vertebra. The target for directing the needle was the trapezoid-shaped echogenic zone between the contiguous articular facets of the lumbosacral vertebral canal visualized in a parasagittal plane. The spinal needle or epidural catheter was inserted in a 45° craniodorsal-caudoventral direction through the subcutaneous tissue and the interarcuate ligament until reaching the epidural space. CT examination confirmed the presence of contrast medium in the epidural space in 25/25 dogs, although a variable contamination of the subarachnoid space was also noted. Findings indicated that this ultrasound-guided epidural injection technique is feasible for normal weight and overweight dogs, with and without radiographic abnormalities of the spine.

Imaging diagnosis-an atypical presentation of diffuse idiopathic skeletal hyperostosis (dish) in a dog.

A 10-year-old female spayed Dalmatian was evaluated for progressive cervical scoliosis and stiffness. This imaging report describes the imaging and postmortem findings for this patient. A diagnosis of an atypical manifestation of diffuse idiopathic skeletal hyperostosis (DISH) was made based on imaging and additional diagnostics. This report serves to increase awareness of DISH in the veterinary community, as well as to describe a unique presentation of the disease with atypical lesion distribution and severity. In addition, this report contrasts the pathophysiology and imaging characteristics of DISH with spondylosis deformans, which can appear comparable radiographically.

Comparison of noncontrast computed tomography and high-field magnetic resonance imaging in the evaluation of Great Danes with cervical spondylomyelopathy.

Computed tomography (CT) provides excellent bony detail, whereas magnetic resonance (MR) imaging is superior in evaluating the neural structures. The purpose of this prospective study was to assess interobserver and intermethod agreement in the evaluation of cervical vertebral column morphology and lesion severity in Great Danes with cervical spondylomyelopathy by use of noncontrast CT and high-field MR imaging. Fifteen client-owned affected Great Danes were enrolled. All dogs underwent noncontrast CT under sedation and MR imaging under general anesthesia of the cervical vertebral column. Three observers independently evaluated the images to determine the main site of spinal cord compression, direction and cause of the compression, articular process joint characteristics, and presence of foraminal stenosis. Overall intermethod agreement, intermethod agreement for each observer, overall interobserver agreement, and interobserver agreement between pairs of observers were calculated by use of kappa (κ) statistics. The highest overall intermethod agreements were obtained for the main site of compression and direction of compression with substantial agreements (κ = 0.65 and 0.62, respectively), whereas the lowest was obtained for right-sided foraminal stenosis (κ = 0.39, fair agreement). For both imaging techniques, the highest and lowest interobserver agreements were recorded for the main site of compression and degree of articular joint proliferation, respectively. While different observers frequently agree on the main site of compression using both imaging techniques, there is considerable variation between modalities and among observers when assessing articular process characteristics and foraminal stenosis. Caution should be exerted when comparing image interpretations from multiple observers.

Evaluation of traditional and novel radiographic vertebral ratios in Great Danes with versus without cervical spondylomyelopathy.

Great Danes are predisposed to osseous-associated cervical spondylomyelopathy (Wobbler syndrome). The first aim of this prospective study was to compare values measured using previously published intravertebral and intervertebral ratio methods and a novel ventrodorsal ratio method in radiographs of clinically normal and affected Great Danes. The second aim was to determine whether these ratios could be used as predictors of sites of spinal cord compression based on magnetic resonance imaging (MRI). Thirty dogs (15 normal, 15 affected) were prospectively enrolled. Lateral and ventrodorsal radiographs were obtained and six measurements were recorded from C3-T1. For each vertebral location, intravertebral ratios and intervertebral ratios were calculated from lateral views, and the ratio of the distance between the articular process joints vs. vertebral body width (novel ventrodorsal ratio) was calculated from ventrodorsal views. Values for these three ratios were compared, by vertebral location and dog group. Intravertebral and intervertebral ratios did not differ between dog groups. The ventrodorsal ratio was significantly smaller in affected Great Danes at C5-6 (P = 0.005) and C6-7 (P < 0.001). The ventrodorsal ratio was significantly associated with MRI presence of spinal cord compression. For each 0.1 unit increase in this ratio value, there was a 65% decrease in the odds of spinal cord compression being present at that site, independent of vertebral location (P = 0.002). Findings from this study supported use of the novel ventrodorsal ratio as an initial radiographic screening method for Great Danes with suspected cervical spondylomyelopathy.

Computed tomographic study analysing functional biomechanics in the thoracolumbar spine of horses with and without spinal pathology.

To better understand physiological and pathological movement patterns in the equine thoracolumbar spine, investigation of the biomechanics on a segmental level requires a constant moment. A constant moment along the spinal column means that the same torque acts on each vertebral segment, allowing the range of motion of different segments to be compared. The aims of this study were to investigate the range of motion of the equine thoracolumbar spine in horses with and without spinal pathology and to examine whether the pressure between the spinous processes depends on the direction of the applied moment. Thoracolumbar spine specimens (T8-L4) of 23 horses were mounted in a custom-made mechanical test rig to investigate spinal biomechanics during lateral bending, axial rotation, flexion and extension using computed tomographic imaging. Results were compared between horses with spondylosis, overriding spinous processes and specimens free of gross pathology. The interspinous space pressure was additionally determined using a foil sensor. The median lateral bending between T9 and L3 was 3.7°-4.1° (IQR 5.4°-8.0°). Maximum rotational movement with inconsistent coupled motion was observed at T9-T16 (p < 0.05). The dorsoventral range of motion was greatest in segments T9-T11 (p < 0.05). Spondylosis and overriding spinous processes restricted spinal mobility, depending on the severity of the condition. There was no significant difference in interspinous pressure during motion (p = 0.54). The biomechanical study confirmed that the range of motion of intervertebral joints depends on the anatomical position of the joint and the direction of the moment applied. Restricted mobility was evident in the presence of different grades of overriding spinous processes or spondylosis. A better understanding of equine spinal biomechanics in horses with spinal pathology facilitates individual rehabilitation.

Priapism associated with lumbar stenosis in a dog.

Priapism, a persistent long-lasting involuntary erection of the penis, is uncommon in dogs. In this report, the case of a 13-year-old male Pointer, referred to our services due to persistent exposition of the penis, is described. This condition was consecutive to an intermittent priapism situation lasting for several days, which has been initially attributed to the inflammation and haematoma associated with a perianal bite. The owners became unable to retract the penis into the prepuce. At presentation, the dog was anorectic for 48 h, intolerant to manipulation, and showed poor body condition and unsteady locomotion. During physical evaluation, a marked engorgement of the local vessels in the prepuce and penis was found. An abdominal X-ray was asked under the suspicion of a neurogenic origin for the clinical situation, which showed evidences of spondylosis. After discussion of the clinical condition, the owners asked for euthanasia. The necropsy confirmed the engorgement of the regional vessels deriving from the pudendal arteries and blood accumulation within all the cavernous spaces, accompanied by congestion and thrombosis within the erectile structures of the penis. No significant changes were observed in the pelvic organs that could be at the origin of priapism. The lumbar-sacral spinal regions were carefully inspected and evidenced signs of L7-S1 stenosis due to spondylosis. The case presented herein is a rare situation of priapism of neurogenic origin in a dog. Necropsy findings suggest that it was consecutive to cauda equina compression due to lumbar spinal stenosis.

Intraobserver and interobserver agreement for results of low-field magnetic resonance imaging in dogs with and without clinical signs of disk-associated wobbler syndrome.

OBJECTIVE: To determine interobserver and intraobserver agreement for results of low-field magnetic resonance imaging (MRI) in dogs with and without disk-associated wobbler syndrome (DAWS). DESIGN: Validation study. ANIMALS: 21 dogs with and 23 dogs without clinical signs of DAWS. PROCEDURES: For each dog, MRI of the cervical vertebral column was performed. The MRI studies were presented in a randomized sequence to 4 board-certified radiologists blinded to clinical status. Observers assessed degree of disk degeneration, disk-associated and dorsal compression, alterations in intraspinal signal intensity (ISI), vertebral body abnormalities, and new bone formation and categorized each study as originating from a clinically affected or clinically normal dog. Interobserver agreement was calculated for 44 initial measurements for each observer. Intraobserver agreement was calculated for 11 replicate measurements for each observer. RESULTS: There was good interobserver agreement for ratings of disk degeneration and vertebral body abnormalities and moderate interobserver agreement for ratings of disk-associated compression, dorsal compression, alterations in ISI, new bone formation, and suspected clinical status. There was very good intraobserver agreement for ratings of disk degeneration, disk-associated compression, alterations in ISI, vertebral body abnormalities, and suspected clinical status. There was good intraobserver agreement for ratings of dorsal compression and new bone formation. Two of 21 clinically affected dogs were erroneously categorized as clinically normal, and 4 of 23 clinically normal dogs were erroneously categorized as clinically affected. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that variability exists among observers with regard to results of MRI in dogs with DAWS and that MRI could lead to false-positive and false-negative assessments.

Distraction-fusion for caudal cervical spondylomyelopathy using an intervertebral cage and locking plates in 14 dogs.

OBJECTIVE: To evaluate clinical and radiographic outcome in dogs with caudal cervical spondylomyelopathy (CCSM) treated with an intervertebral fusion cage and locking plates. STUDY DESIGN: Prospective clinical study. ANIMALS: Large breed dogs (n=14) with CCSM. METHODS: Dogs had single level cervical spine distraction/fusion performed using an intervertebral cage with a hollow center filled with cancellous autograft and 2 ventrally applied locking plates. Outcome was measured using neurologic scores and radiographic interpretation 6 weeks, 6 months, and 12 months postoperatively. RESULTS: The surgical procedure was well tolerated in all dogs. Final outcome at 12 months was available in 9 dogs. Five dogs were judged excellent, 1 dog was good, 2 dogs were satisfactory, and 2 dogs were poor because of adjacent segment disease. Four dogs died for reasons unrelated to the procedure. Radiographically, implants remained stable over the entire follow-up period. The disc space continued to fill with an immature pattern of new bone, which showed progressive increase in opacity and quantity. Subsidence of the cage (median 2 m) was detected in 9 dogs at 6 weeks and remained unchanged in those that could be followed further. CONCLUSION: Distraction-fusion of single level CCSM in dogs with a combination of intervertebral cage and ventral locking plates is clinically effective and results in successful bony fusion.

Caudal cervical arthrodesis using a distractable fusion cage in a dog.

This case report describes a cervical fusion cage, surgical technique and the long-term outcome of caudal cervical arthrodesis used to stabilise dynamic spinal cord compression at the sixth and seventh cervical intervertebral disc space (C6, C7) in a dog. A seven-year-old, 41 kg, entire male Dobermann Pinscher was admitted for progressive ataxia of two weeks duration. Neurological examination revealed ambulatory tetraparesis. Computed tomographic myelogram scans in neutral and traction positions of the neck were performed and were used to determine presence of a dynamic component. A C6-C7 surgical distraction and stabilisation using a distractable intervertebral fusion cage was performed. There was not any deterioration of neurological status was observed on postoperative neurological evaluation. Within eight weeks after surgery, gait and postural abilities had returned to normal. Computed tomography evaluation indicated a complete bridging callus within and outside the cage at 15 weeks after surgery. There were not any complications or recurrences of initial neurological deficits observed during the 40 month follow-up period. Based on the follow-up period data, a C6-C7 dynamic spinal cord compression with disc protrusion was successfully treated by a distractable cervical fusion cage.

Radiographic and scintigraphic evaluation of spondylosis in the equine thoracolumbar spine: a retrospective study.

REASONS FOR PERFORMING STUDY: Clinical, radiographic and scintigraphic signs associated with spondylosis of the equine thoracolumbar spine have been poorly documented. OBJECTIVES: To establish an objective radiographic and scintigraphic grading system for spondylosis lesions; to estimate the prevalence of spondylosis in a population of horses with back pain; and to compare the results of radiography and scintigraphy. METHODS: Radiographic images of the thoracolumbar spine from 670 horses with clinical signs of back pain were graded. Scintigraphic images from horses with spondylosis lesions underwent subjective and objective analysis. Sensitivity and specificity of scintigraphy for detection of spondylosis relative to radiography for identification of spondylosis were calculated, and Chi-squared analysis was performed to test for an association between location and severity of lesions. RESULTS: Twenty-three of 670 horses (3.4%) with back pain had radiographic evidence of spondylosis. Of these horses, 14 (61%) had more than one lesion and 44% (n=22) of lesions occurred between T11-T13 vertebral bodies. Only 33% (n=28) of locations with radiographic changes had increased radiopharmaceutical uptake. CONCLUSION: Spondylosis occurs at a low prevalence in horses with back pain. It may be present alone or in association with other osseous abnormalities. The clinical significance of spondylosis needs further investigation. POTENTIAL RELEVANCE: Spondylosis is uncommon but may be a contributor to back pain in the horse.

Bilateral iliopsoas muscle contracture and spinous process impingement in a German Shepherd dog.

OBJECTIVE: To report diagnosis and treatment of bilateral iliopsoas muscle contracture in a dog with spinous process impingement. STUDY DESIGN: Case report. ANIMALS: German Shepherd dog. METHODS: A dog with chronic progressive lameness, flexion contracture of the coxofemoral joints, severe pain, and decreased femoral reflexes had severe spondylosis bridging the vertebral bodies from L1 to L4 and enlarged dorsal spinous processes from T8 to L6 with impingement and bony proliferation. Ultrasonographic and magnetic resonance imaging (MRI) findings were consistent with fibrosis, mineralization, and atrophy of the iliopsoas muscles bilaterally which was treated by staged tenectomy of the insertions of the iliopsoas muscles. RESULTS: Because of severe perivascular fibrosis, the femoral vessels required ligation. Bilateral iliopsoas muscle tenectomy improved gait and provided pain relief. Histologic findings were consistent with fibrotic myopathy. CONCLUSIONS: Slow progression of severe clinical signs observed bilaterally in this dog differs from previous reports of iliopsoas myopathy. Findings were similar to the fibrotic myopathy of the gracilis or semitendinosus muscles described in dogs. CLINICAL RELEVANCE: Iliopsoas muscle abnormalities should be considered in dogs with limited hip extension and pain. MRI is useful for diagnosing muscle fibrosis. Iliopsoas tenectomy may improve clinical function in dogs with fibrotic myopathy.

Cervical spine locking plate fixation for treatment of cervical spondylotic myelopathy in large breed dogs.

OBJECTIVE: To describe indirect decompression by means of cervical spine locking plate (CSLP) fixation with vertebral distraction, discectomy, and cancellous block bone grafting in large breed dogs with single caudal cervical dynamic spondylotic lesions diagnosed by myelography with linear traction to the cervical spine, and contrast-enhanced computed tomography. STUDY DESIGN: Prospective clinical study. ANIMALS: Dogs (n=12) with caudal cervical spondylotic myelopathy because of a single dynamic, traction-responsive lesion. METHODS: Single, traction-responsive, caudal cervical spondylotic lesions were treated by vertebral distraction, discectomy, cancellous block bone grafting, and CSLP fixation. Follow-up was obtained by sequential recheck examination by the author or referring veterinarian or by telephone inquiries. RESULTS: Ten dogs had neurologic improvement after surgery. Indirect decompression by maintained distraction with cancellous block grafting and CSLP fixation was readily accomplished with less risk of blood loss or iatrogenic spinal cord injury than that associated with direct (ventral) decompression. There were no complications of graft intrusion, extrusion or subsidence, implant loosening, foraminal impingement, or end-plate failure. Two dogs that had satisfactory short-term recoveries developed clinical signs associated with adjacent segment disease and were euthanatized. At long-term follow-up, 8 dogs had satisfactory function, either a normal gait or one with slight to moderate proprioceptive deficits. CONCLUSIONS: CSLP fixation with cancellous block interbody grafting is an effective and perhaps safer method of treating single-level, traction-responsive cervical spondylosis in large breed dogs. CLINICAL RELEVANCE: CSLP fixation with interbody bone grafting is a viable alternative to other techniques for treatment of single-level, traction-responsive cervical spondylosis.

Spondylosis deformans as an indicator of transport activities in archaeological dogs: A systematic evaluation of current methods for assessing archaeological specimens.

Over the past several decades archaeologists have used the spinal pathology spondylosis deformans as an indicator that archaeological dogs were used to pull or carry loads. This interpretive approach is largely based upon observations of prehistoric dog remains and archaeologist's interpretations of veterinary literature on recent sled dogs and other draft animals. However, no comparative large-scale studies of the occurrence of spondylosis deformans in wild canids, transport dogs, and dogs never involved in pulling or carrying loads have been published. To evaluate the reliability of spondylosis deformans in archaeological dogs as an indicator of participation in transport activities, 136 modern non-transport dogs, 19 sled dogs, and 241 wolves were systematically analyzed for the occurrence of spondylosis deformans. Our results indicate this pathology is not a reliable skeletal indicator of dog transport because the disease is prevalent in both dogs and wolves, regardless of their occupational histories. Numerous factors correlate with the occurrence and manifestation of this disease in canids, including age, body size, sex, and inbreeding. As such, it remains extremely challenging to identify specific etiologies for spondylosis deformans in archaeological specimens.

Vertebral stabilisation and selective decompression for the management of triple thoracolumbar disc protrusions.

Triple adjacent thoracolumbar disc protrusions causing moderate to severe spinal cord compression were diagnosed by magnetic resonance imaging in two German shepherd dogs with marked paraparesis and pelvic limb ataxia. Both cases were managed by selective hemilaminectomy, partial annulectomy and bilateral quadruple vertebral body stabilisation using novel canine locking fixation plates (SOP). The stabilisation of multiple vertebrae in the thoracolumbar spine was possible because the plates could be contoured with six degrees of freedom. Spinal pain resolved and neurological function improved in both dogs. Screw breakage was evident in one dog five months following surgery.

Spondylosis deformans in three large canids from the Gravettian Predmostí site: Comparison with other canid populations.

Spondylosis deformans is a common degenerative condition of the spinal column, especially in modern domestic dogs. The presence and severity of lesions are related to age and physical activity, but they can be influenced by genetics, with some modern breeds being particularly predisposed. Spondylosis deformans also has been reported in prehistoric dogs. Here, we describe three affected vertebrae, likely from three individuals, in a large canid assemblage from the Gravettian Predmostí site, Czech Republic. We compare the proportion of affected individuals from the Predmostí assemblage with that of affected individuals among recent wild Northern wolves, inbred wolves, captive wolves, and recent Northern dogs. The proportion of affected individuals among the captive wolves differs significantly from the other wolf groups. The proportion in the Predmostí assemblage does not differ significantly from that of the wild wolf groups.

Temporospatial and kinetic gait variables of Doberman Pinschers with and without cervical spondylomyelopathy.

OBJECTIVE: To characterize and compare gait variables in Doberman Pinschers with and without cervical spondylomyelopathy (CSM). ANIMALS: 18 Doberman Pinschers (9 clinically normal dogs and 9 CSM-affected dogs). PROCEDURES: A neurologic examination was performed on all dogs. The diagnosis of CSM was confirmed with MRI. Temporospatial and kinetic gait variables were measured by use of a pressure-sensitive walkway. Temporospatial variables evaluated included stance phase duration, swing phase duration, gait cycle duration, stride length, and gait velocity. Kinetic variables evaluated included peak vertical force and vertical impulse. Random-effects linear regression was used to determine the difference between CSM-affected and clinically normal dogs for each of the 7 variables. RESULTS: Values for temporospatial variables were significantly smaller in the thoracic limbs of CSM-affected dogs, compared with values for the thoracic limbs of clinically normal dogs. For the kinetic variables, peak vertical force was significantly higher in the thoracic limbs than the pelvic limbs for all dogs. Vertical impulse values were higher in the thoracic limbs than the pelvic limbs. There were significant differences in mean vertical impulse between the thoracic and pelvic limbs for both groups. CONCLUSIONS AND CLINICAL RELEVANCE: In this study, significant differences in temporospatial variables were identified between the thoracic limbs of clinically normal and CSM-affected dogs, with the values being smaller for the CSM-affected dogs than for the clinically normal dogs. A pressure-sensitive walkway may provide a valid, practical option for rapid, objective assessment of gait and response to treatment in dogs with CSM.