Frequency of urinary tract infection in catheterized dogs and comparison of bacterial culture and susceptibility testing results for catheterized and noncatheterized dogs with urinary tract infections

OBJECTIVE

To determine frequency of urinary tract infections (UTIs) in catheterized dogs that had intervertebral disk disease (IVDD) or disease other than IVDD and compare bacterial culture and susceptibility testing results for catheterized and noncatheterized dogs with UTIs.

DESIGN

Retrospective cohort study.

ANIMALS

147 catheterized dogs (105 with IVDD and 42 with other diseases) and 99 noncatheterized dogs with UTIs.

PROCEDURES

Medical records were reviewed for signalment, history, clinical problem, duration of urinary tract catheterization, administration of drugs, and urine bacterial culture and susceptibility testing results.

RESULTS

Forty-two percent (44/105) of dogs with IVDD and 55% (23/42) of dogs with other diseases had UTIs; this difference was not significant. For catheterized dogs, the odds of UTI were increased by 20% for each year increase in age, 27% for each day increase in duration of catheterization, and 454% with antimicrobial administration. Escherichia coli and Proteus spp were more frequently isolated from noncatheterized dogs, whereas Enterobacter spp and Staphylococcus spp were more frequently isolated from catheterized dogs. There was no significant difference in frequency of 1, 2, or 3 isolates between groups. Proportions of antimicrobials to which the most frequently isolated bacteria were resistant were not significantly different between groups.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested that urinary tract catheterization is a reasonable alternative for management of dogs with urinary bladder dysfunction, but that duration of catheterization should be minimized and indiscriminate antimicrobial administration to dogs with indwelling urinary catheters should be avoided.

Electro-acupuncture and Chinese herbs for treatment of cervical intervertebral disk disease in a dog

A non-ambulatory dog with tetraparesis following a pain episode that had evolved over 2 months was submitted for medical treatment and diagnosed with intervertebral disk disease at C3-C4 and dorsal extradural compression at C1-C2 and C3-C4 using myelography and computed tomography. The dog experienced ambulation recovery after 15 days of treatment with only electroacupuncture and Chinese herbal medicine, with marked improvement occurring after only 10 treatments. Six months of follow-up demonstrated that the dog was stable and had no recurrence of symptoms. Therefore, it was concluded that the combination of electroacupuncture and Chinese herbal medicine was responsible for motor rehabilitation.

Magnetic resonance imaging of traumatic intervertebral disc extrusion in dogs

This retrospective study evaluated the magnetic resonance (mr) images of traumatic disc extrusions in 11 dogs. The findings included a reduction in the volume and signal intensity of the nucleus pulposus, focal hyperintensity within the overlying spinal cord on T (2)-weighted mr images, and subtle spinal cord compression, extraneous material or signal change within the vertebral canal. The largest area of hyperintensity in the spinal cord was directly over or close to the affected disc space, appeared asymmetrical and in the majority of cases was less than one vertebra in length. Parenchymal spinal cord haemorrhage was identified in four of the dogs. Vacuum phenomena, evident as a signal void in the centre of the disc, were identified in two of the dogs. The mr images were distinct from those reported for other causes of spinal cord dysfunction.

Thoracolumbar dorsolateral laminectomy with osteotomy of the spinous process in fourteen dogs

OBJECTIVE

To describe outcome after an alternative unilateral approach to the thoracolumbar spine for dorsal laminectomy.

STUDY DESIGN

Retrospective clinical study.

ANIMALS

Dogs (n=14) with thoracolumbar spinal cord compression.

METHODS

Thoracolumbar spinal cord compression was lateral (6 dogs), dorsal (4), and dorsolateral (4) caused by subarachnoid (7) and synovial cysts (2) and intradural-extramedullary neoplasia (5). All dogs were treated by dorsal laminectomy with osteotomy of the spinous process using a unilateral paramedian approach. The contralateral paraspinal muscles were not stripped from the spinous process and the osteoligamentous complexes were preserved. Retraction of the spinous process and muscles to the contralateral side resulted in complete visualization of the dorsal vertebral arch thereby allowing dorsal laminectomy to be performed.

RESULTS

No technique complications occurred. Approximately 75% exposure of the spinal cord (dorsal and lateral compartments) was achieved providing adequate visualization and treatment of the lesions. Transient deterioration of neurologic state occurred in 5 dogs because of extensive spinal cord manipulation. At long-term follow-up, 6 dogs were normal, 6 had clinical improvement, and 2 were unchanged.

CONCLUSION

Dorsal laminectomy after osteotomy and retraction of the spinous process may be considered in canine patients with dorsal, dorsolateral, or lateral compression to facilitate adequate decompression of the spinal cord.

CLINICAL SIGNIFICANCE

This surgical technique offers an alternative approach to the thoracolumbar spine and spinal cord by a modified dorsal laminectomy that preserves the paraspinal muscle integrity on the contralateral side.

Closed Fluoroscopic-Assisted Spinal Arch External Skeletal Fixation for the Stabilization of Vertebral Column Injuries in Five Dogs

OBJECTIVE

To evaluate outcome after closed fluoroscopic-assisted application of spinal arch external skeletal fixators in dogs with vertebral column injuries.

STUDY DESIGN

Retrospective case series.

ANIMALS

Dogs with traumatic vertebral column injuries (n=5).

METHODS

Medical records of dogs with vertebral column fractures and/or luxations stabilized with spinal arch external skeletal fixator frames applied using a closed fluoroscopic-assisted technique were reviewed. Owners were contacted to obtain long-term clinical outcomes.

RESULTS

Five dogs (age range, 6-72 months; weight, 10-54 kg) had traumatic vertebral column injuries stabilized with spinal arch external skeletal fixators applied in closed fashion. Injuries involved vertebral segments of the thoracolumbar junction, lumbar spine, and lumbosacral junction. Immediately postoperatively, 4 dogs had anatomic alignment of their vertebral fracture/luxation; 1 dog had 1 mm of vertebral canal height compromise. Time to fixator removal ranged from 65 to 282 days (141+/-87 days). All dogs had regained satisfactory neurologic function by 3 months. At long-term follow-up (range, 282-780 days; mean 445+/-190 days) all dogs were judged to have good to excellent return of function by their owners.

CONCLUSION

Successful closed fluoroscopic-assisted application of external skeletal fixators using spinal arches provided satisfactory reduction with few complications in 5 dogs. Return to function was judged to be good to excellent in all dogs at long-term evaluation.

CLINICAL RELEVANCE

Closed fluoroscopic-assisted application of ESF using spinal arches provided satisfactory reduction and effective stabilization of spinal fractures with few complications and should be considered as a treatment approach.

Biomechanical Evaluation of Cervical Intervertebral Plug Stabilization in an Ovine Model

OBJECTIVE

(1) To determine the biomechanical stability of cervical spinal segment C5-C6 after ventral slot (VS) decompression and distraction-stabilization by a modified polymethylmethacrylate (PMMA) intervertebral plug technique (IVP) in an ovine model. (2) To determine if the distraction of the disk space is maintained after VS-IVP, and the frequency of bony intervertebral union.

STUDY DESIGN

Experimental in vivo study in an ovine model with an in vitro control study.

ANIMALS

Adult (>2 years age), intact sheep (n=18).

METHODS

Ten sheep had VS/IVP surgery of C5-6 with computed tomography (CT) images obtained immediately before and after surgery, as well as 8 (n=10) and 24 (n=5) weeks postoperatively. Cervical spines harvested 8 weeks (8-week group; n=5) and 24 weeks (24-week group; n=5) after surgery had three-dimensional (3D) flexibility tests in flexion-extension, axial rotation, and lateral bending. Image data was analyzed qualitatively and quantitatively in 3D. Eight ovine cervical spines served as controls and had biomechanical testing in intact condition (n=5) and after in vitro VS/IVP (n=5).

RESULTS

Significantly decreased range of motion (ROM) was noted in all loading modes when comparing in vitro operated spines and the 24-week group to intact spines. The 8-week group was not significantly different from the intact group, except in lateral bending. Quantitative CT analysis of treatment groups showed progressive disk space collapse and ventral implant migration. Intervertebral bony union did not occur.

CONCLUSION

Biomechanical stability was obtained immediately after VS/IVP surgery, but ROM at 8 weeks was not different from intact spines. However, at 24 weeks, the operated level had regained stability similar to the immediate postoperative level. Distraction of the disk space was not maintained and bony union did not occur in this ovine model of VS/IVP.

CLINICAL RELEVANCE

In clinical situations requiring constant increased stability of cervical segments for an extended time, more rigid stabilization techniques are required.

One-year clinical and magnetic resonance imaging follow-up of Doberman Pinschers with cervical spondylomyelopathy treated medically or surgically

OBJECTIVE

To evaluate progression of clinical signs and magnetic resonance imaging (MRI) findings in dogs with cervical spondylomyelopathy (wobbler syndrome) treated medically or surgically.

DESIGN

Prospective cohort study.

ANIMALS

12 Doberman Pinschers.

PROCEDURES

Neurologic examinations and MRI were performed before medical (n = 9) or surgical treatment (ventral slot, 3) and a minimum of 12 months later.

RESULTS

Mean follow-up time was 14.5 months. Clinically, 2 dogs improved after surgical treatment and 5 improved after medical treatment. Magnetic resonance imaging of surgically treated dogs revealed adequate spinal cord decompression. Spinal cord signal changes were seen in 2 dogs before surgery, both of which had new signal changes at the same and adjacent sites during follow-up examination. One dog treated surgically developed 3 new areas of spinal cord compression. In the medically treated dogs, the severity of spinal cord compression at the time of follow-up examination was unchanged in 4 dogs, worse in 2 dogs, and improved in 3 dogs, but spinal cord atrophy was observed on transverse images. Four medically treated dogs had changes in spinal cord signal initially, but none developed new signal changes or compressions.

CONCLUSIONS AND CLINICAL RELEVANCE

Medical and surgical treatment improved or stabilized the clinical condition of most dogs. Surgical treatment appeared to hasten the development of additional areas of spinal cord compression and lesions in dogs with preoperative cord changes; however, the clinical importance of these changes was not determined. The progression of pathologic MRI abnormalities was notably less in medically treated dogs, compared with surgically treated dogs.

Syringomyelia in cavalier King Charles spaniels: the relationship between syrinx dimensions and pain

OBJECTIVES

This study was designed to test the hypothesis that pain associated with syringomyelia in dogs is dependent upon size and involvement of the dorsal part of the spinal cord.

METHODS

Masked observers determined syrinx dimensions and precise location within the spinal cord on magnetic resonance images of 55 cavalier King Charles spaniels with syringomyelia. After removal of masking, syrinx size and location were compared between the cohorts of dogs that exhibited pain with those that did not.

RESULTS

Maximum syrinx width was the strongest predictor of pain, scratching behaviour and scoliosis in dogs with syringomyelia. Both pain and syrinx size were positively correlated with syrinxes located in the dorsal half of the spinal cord.

CLINICAL SIGNIFICANCE

Large syrinxes associated with damage to the dorsal part of the spinal cord are associated with persistent pain suggesting that the pain behaviour expressed by this group of patients is likely to be "neuropathic pain," resulting from disordered neural processing in the damaged dorsal horn. As such it is likely that conventional analgesic medication may be ineffective.

Tri-level surgical treatment of cervical spinal cord compression in a Thoroughbred yearling

A Thoroughbred yearling was presented with neurological, radiographic, and myelographic abnormalities consistent with cervical vertebral stenotic myelopathy. Surgical correction was performed by using ventral cervical interbody fusion at 3 intervertebral spaces. The patient recovered uneventfully from surgery. The neurological status remained unchanged initially; however, significant improvement was noted 37 weeks postoperatively.

Compressive cervical myelopathy in young Texel and Beltex sheep

BACKGROUND

This investigation was prompted by the referral of increasing numbers of young Texel and Beltex rams with ataxia and weakness, or wobbler syndrome.

HYPOTHESIS

The study aims were to describe the clinical and pathologic findings in affected sheep.

ANIMALS

The animals evaluated in this study included 7 Texel sheep (6 male and 1 female) and 3 Beltex sheep (2 male and 1 female) referred from pedigree flocks. Typically, the sheep were 15-18 months of age at referral.

METHODS

Diagnostic investigations included radiographic and computed tomographic (CT) myelography followed by gross postmortem and histopathologic examinations.

RESULTS

Clinical findings typical of cervical spinal cord compression were present in all sheep but varied in severity. Myelography confirmed dorsal spinal cord compression in the region of C6-C7. No bony abnormalities were identified as described in cases of canine and equine wobbler syndrome. Postmortem examinations revealed discrete, smooth, nodular to polypoid projections of adipose tissue apparently prolapsing through the dorsolateral intervertebral space at C6-C7 and causing localized spinal cord compression. Histopathology of the nodules confirmed that they were composed of well-differentiated adipocytes typical of fatty tissue. Spinal cord lesions were similar in all sheep with marked Wallerian degeneration at the site of compression and mild Wallerian degeneration present cranial and caudal to the lesion.

CONCLUSIONS AND CLINICAL IMPORTANCE

The findings of this study suggest a novel cervical myelopathy in these sheep breeds caused by the presence of fatty nodules encroaching into the dorsal vertebral canal at C6-C7. Additional investigations are required to establish the etiology and possible hereditary risk factors for this unique clinicopathologic syndrome.

Treatment of thoracolumbar spinal cord compression associated withHistoplasma capsulatuminfection in a cat

CASE DESCRIPTION

A 7-year-old domestic shorthair cat with a 2-month history of decreased appetite and weight loss was examined because of paraparesis of 1 week's duration that had progressed to paraplegia 3 days earlier.

CLINICAL FINDINGS

Neurologic examination revealed normo- to hyperreflexia and absence of deep pain sensation in the hind limbs and thoracolumbar spinal hyperesthesia. Neuro-anatomically, the lesion was located within the T3 through L3 spinal cord segments. Biochemical analysis and cytologic examination of CSF revealed no abnormalities. Radiography revealed narrowing of the T11-12 intervertebral disk space and intervertebral foramen suggestive of intervertebral disk disease. Myelography revealed an extradural mass centered at the T12-13 intervertebral disk space with extension over the dorsal surfaces of T11-13 and L1 vertebral bodies.

TREATMENT AND OUTCOME

A right-sided hemilaminectomy was performed over the T11-12, T12-13, and T13-L1 intervertebral disk spaces, and a space-occupying mass was revealed. Aerobic bacterial culture of samples of the mass yielded growth of a yeast organism after a 10-day incubation period; histologically, Histoplasma capsulatum was identified. Treatment with itraconazole was initiated. Nineteen days after surgery, superficial pain sensation and voluntary motor function were evident in both hind limbs. After approximately 3.5 months, the cat was ambulatory with sling assistance and had regained some ability to urinate voluntarily.

CLINICAL RELEVANCE

In cats with myelopathies that have no overt evidence of fungal dissemination, differential diagnoses should include CNS histoplasmosis. Although prognosis associated with fungal infections of the CNS is generally guarded, treatment is warranted and may have a positive outcome.

Treatment of traumatic cervical myelopathy with surgery, prolonged positive-pressure ventilation, and physical therapy in a dog

CASE DESCRIPTION

A 9-year-old dog was evaluated for traumatic cervical myelopathy after a surgical attempt to realign and stabilize the C2 and C3 vertebrae.

CLINICAL FINDINGS

The dog could not ventilate spontaneously and was tetraplegic; positive-pressure ventilation (PPV) was maintained. Myelography and computed tomography revealed spinal cord compression with subluxation of the C2 and C3 vertebrae and extrusion of the C2-3 intervertebral disk.

TREATMENT AND OUTCOME

Surgically, the protruding disk material was removed and the vertebrae were realigned with screws and wire. For PPV, assist control ventilation in volume control mode and then in pressure control mode was used in the first 6 days; this was followed by synchronized intermittent mandatory ventilation until 33 days after the injury; then only continuous positive airway pressure was provided until the dog could breathe unassisted, 37 days after the injury. Physical therapy that included passive range of motion exercises, neuromuscular electrical stimulation, and functional weight-bearing positions was administered until the dog was discharged 46 days after injury; the dog was severely ataxic and tetraparetic but could walk. Therapy was continued at home, and 1 year later, the dog could run and had moderate ataxia and tetraparesis.

CLINICAL RELEVANCE

Hypoventilation with tetraparesis in traumatic spinal cord injury can be successfully treated with PPV exceeding 30 days, surgery, and physical therapy.

Imaging diagnosis--infiltrative lipoma causing spinal cord compression in a dog

An 11-year-old, 43 kg neutered female Labrador retriever dog developed acute pelvic limb paraparesis. In magnetic resonance images there was a T1- and T2-hyperintense extradural at the fifth thoracic intervertebral space that was causing marked compression of the spinal cord. In short tau inversion recovery and fat suppressed T1-weighted images the signal from the mass was decreased indicating it was of fatty origin. The mass was removed via a dorsal hemilaminectomy in the thoracic area. Histopathologic analysis confirmed the mass was an infiltrative lipoma. The dog recovered and is fully ambulatory 24 months after surgery. This report provides additional evidence that lipomas in the vertebral canal may be the source of pelvic limb neuropathy and also illustrates the value of magnetic resonance imaging in establishing the fatty nature of some soft tissue masses.

Distraction with bone cement plug as a treatment of caudal cervical spondylomyelopathy--report of three cases

The aim of this report is the presentation of disc-associated caudal cervical spondylomyelopathy cases in dogs treated with the method of distraction and stabilization with the cement plug. Surgical operations were performed in 2 rottweilers and one cross-breed. In one case, two lesions were operated at the same time and in one it was a recurrence after 4 years (in the intervertebral space adjacent to the operated one--domino effect). Two cases were cured, in one the health state became worse and the patient was euthanitized. The applied method may give good clinical effects, however, some improvements could still be introduced.

Association of spinal cord compression seen on magnetic resonance imaging with clinical outcome in 67 dogs with thoracolumbar intervertebral disc extrusion

OBJECTIVES

To determine whether there is an association between the degree of transverse spinal cord compression detected by magnetic resonance imaging following thoracolumbar Hansen type 1 intervertebral disc disease in dogs and their presenting and postsurgical neurological status.

METHODS

Medical records of 67 dogs with surgically confirmed Hansen type 1 intervertebral disc disease (2000 to 2004) were reviewed to obtain the rate of onset of disease, duration of clinical signs and presurgical and postsurgical neurological grade. Percentage of spinal cord compression was determined on transverse T2-weighted magnetic resonance images. Linear regression was used to examine the association between spinal cord compression and each of the above variables. Chi-squared tests were used to examine associations among postsurgical outcome and presurgical variables.

RESULTS

Eighty-five per cent (57 of 67) of dogs were chondrodystrophoid. Mean spinal cord compression was 53 per cent (sd=219.7, range 14.3 to 84.9 per cent). There was no association between the degree of spinal cord compression and the neurological grade at presentation, rate of onset of disease, duration of clinical signs or postsurgical outcome, with no difference between chondrodystrophoid and non-chondrodystrophoid dogs.

CLINICAL SIGNIFICANCE

The degree of spinal cord compression documented with magnetic resonance imaging in dogs with thoracolumbar Hansen type 1 intervertebral disc disease was not associated with the severity of neurological signs and was not a prognostic indicator in this study.

Correlation of motor evoked potentials with magnetic resonance imaging and neurologic findings in Doberman Pinschers with and without signs of cervical spondylomyelopathy

OBJECTIVE

To establish the reference ranges for motor evoked potential (MEP) latency and amplitude in clinically normal Doberman Pinschers, compare the MEPs of Doberman Pinschers with and without clinical signs of cervical spondylomyelopathy (CSM; wobbler syndrome), and determine whether MEP data correlate with neurologic or magnetic resonance imaging (MRI) findings.

ANIMALS

16 clinically normal and 16 CSM-affected Doberman Pinschers.

PROCEDURES

Dogs were classified according to their neurologic deficits. After sedation with acepromazine and hydromorphone, transcranial magnetic MEPs were assessed in each dog; latencies and amplitudes were recorded from the extensor carpi radialis and cranial tibial muscles. Magnetic resonance imaging was performed to evaluate the presence and severity of spinal cord compression.

RESULTS

Significant differences in cranial tibial muscle MEP latencies and amplitudes were detected between clinically normal and CSM-affected dogs. No differences in the extensor carpi radialis MEP were detected between groups. There was a significant correlation (r = 0.776) between the cranial tibial muscle MEP latencies and neurologic findings. Significant correlations were also found between MRI findings and the cranial tibial muscle MEP latencies (r = 0.757) and amplitudes (r = -0.453).

CONCLUSIONS AND CLINICAL RELEVANCE

Results provided a reference range for MEPs in clinically normal Doberman Pinschers and indicated that cranial tibial muscle MEP latencies correlated well with both MRI and neurologic findings. Because of the high correlation between cranial tibial muscle MEP data and neurologic and MRI findings, MEP assessment could be considered as a screening tool in the management of dogs with spinal cord disease.

SUBFASCIAL SEROMA CAUSING COMPRESSIVE MYELOPATHY AFTER CERVICAL DORSAL LAMINECTOMY

Dorsal surgical approach to the cervical vertebral canal is indicated for a variety of spinal cord diseases. Compressive myelopathy due to subfascial seroma following dorsal laminectomy has not previously been documented in dogs. We describe neurologic findings, magnetic resonance (MR) imaging characteristics and clinical outcome in a young Rottweiler experiencing this complication after a successful dorsal decompression for treatment of cervical stenotic myelopathy. MR imaging allowed detection of pockets of high signal intensity material on T2-weighted images and low signal intensity in T1-weighted images. Prompt surgical revision and drainage allowed complete recovery.

COMPARISON OF MAGNETIC RESONANCE IMAGING AND MYELOGRAPHY IN 18 DOBERMAN PINSCHER DOGS WITH CERVICAL SPONDYLOMYELOPATHY

Eighteen Doberman pinscher dogs with clinical signs of cervical spondylomyelopathy (wobbler syndrome) underwent cervical myelography and magnetic resonance (MR) imaging. Cervical myelography was performed using iohexol, followed by lateral and ventrodorsal radiographs. Traction myelography was performed using a cervical harness exerting 9 kg of linear traction. MR imaging was performed in sagittal, transverse, and dorsal planes using a 1.5 T magnet with the spine in neutral and traction positions. Three reviewers independently evaluated the myelographic and MR images to determine the most extensive lesion and whether the lesion was static or dynamic. All reviewers agreed with the location of the most extensive lesion on MR images (100%), while the agreement using myelography was 83%. The myelogram and MR imaging findings agreed in the identification of the affected site in 13-16 dogs depending on the reviewer. MR imaging provided additional information on lesion location because it allowed direct examination of the spinal cord diameter and parenchyma. Spinal cord signal changes were seen in 10 dogs. Depending on the reviewer, two to four dogs had their lesions classified as dynamic on myelography but static on MR images. Myelography markedly underscored the severity of the spinal cord compression in two dogs, and failed to identify the cause of the signs in another. The results of this study indicated that, although myelography can identify the location of the lesion in most patients, MR imaging appears to be more accurate in predicting the site, severity, and nature of the spinal cord compression.

Morphologic and morphometric magnetic resonance imaging features of Doberman Pinschers with and without clinical signs of cervical spondylomyelopathy

OBJECTIVE

To compare morphologic and morphometric features of the cervical vertebral column and spinal cord of Doberman Pinschers with and without clinical signs of cervical spondylomyelopathy (CSM; wobbler syndrome) detected via magnetic resonance imaging (MRI).

ANIMALS

16 clinically normal and 16 CSM-affected Doberman Pinschers.

PROCEDURES

For each dog, MRI of the cervical vertebral column (in neutral and traction positions) was performed. Morphologically, MRI abnormalities were classified according to a spinal cord compression scale. Foraminal stenosis and intervertebral disk degeneration and protrusion were also recorded. Morphometric measurements of the vertebral canal and spinal cord were obtained in sagittal and transverse MRI planes.

RESULTS

4 of 16 clinically normal and 15 of 16 CSM-affected dogs had spinal cord compression. Twelve clinically normal and all CSM-affected dogs had disk degeneration. Foraminal stenosis was detected in 11 clinically normal and 14 CSM-affected dogs. Vertebral canal and spinal cord areas were consistently smaller in CSM-affected dogs, compared with clinically normal dogs. In neutral and traction positions, the intervertebral disks of CSM-affected dogs were wider than those of clinically normal dogs but the amount of disk distraction was similar between groups.

CONCLUSIONS AND CLINICAL RELEVANCE

The incidence of intervertebral disk degeneration and foraminal stenosis in clinically normal Doberman Pinschers was high; cervical spinal cord compression may be present without concurrent clinical signs. A combination of static factors (ie, a relatively stenotic vertebral canal and wider intervertebral disks) distinguished CSM-affected dogs from clinically normal dogs and appears to be a key feature in the pathogenesis of CSM.

Tibiotarsal fracture and neurologic problems of a black-eared kite (Milvus migrans)

A wild-caught black-eared kite (Milvus migrans) was presented with a fracture of the right fibula and tibiotarsus that was repaired using combined crossed pins and a rigid cast technique. The fracture healed well; however, because the bird was not able to regain full use of its legs, radiographs were taken, which revealed a translucent structure involving the vertebral bodies of the notarium-synsacrum area. The condition of the bird deteriorated over the following days, and it was euthanized. Postmortem examination confirmed two bony intumescences involving the last vertebra of the notarium and the synsacrum. The vertebral canal, on a cut surface, was restricted, and the spinal cord was compressed.

Onchocercosis of an intervertebral joint capsule causing cervical vertebral stenotic myelopathy in a horse

A novel case where onchocercosis was identified as a cause of cervical myelopathy in the horse is described. A 15-year-old Connemara mare was euthanized due to progressive locomotion disturbance. Postmortem examination revealed soft-tissue swelling in the intervertebral joint capsule of C6-7 with narrowing of the vertebral canal. On light microscopy, axonopathy was pronounced in the corresponding segment of the spinal cord. Fibrous tissue and eosinophilic granulomas were found in the joint capsule, together with parasites identified histologically as Onchocerca sp.

Spinal epidural empyema in seven dogs

OBJECTIVE

To characterize the clinical signs, diagnostic and surgical findings, and outcome in dogs with spinal epidural empyema (SEE).

STUDY DESIGN

Retrospective study.

ANIMALS

Seven dogs.

METHODS

Dogs with SEE between 1992 and 2001 were identified from a computerized medical record system. Inclusion criteria were: neurologic examination, vertebral column radiographs, myelography, antimicrobial culture and susceptibility of material collected surgically from the vertebral canal, a definitive diagnosis of SEE confirmed by surgery, and microscopic examination of tissue from the vertebral canal.

RESULTS

Common signs were lethargy, fever, anorexia, apparent spinal pain, and paraparesis/plegia. Common laboratory abnormalities were peripheral neutrophilia, and neutrophilic pleocytosis in cerebrospinal fluid (CSF). Three dogs had concurrent discospondylitis and 1 of these had vertebral luxation. On myelography, extradural spinal cord compression was focal (2 dogs), multifocal (3), or diffuse (2). Bacteria were isolated not from CSF but from blood, surgical site, pleural fluid, or urine in 6 dogs. Dogs were administered antibiotics and had surgical decompression by hemilaminectomy. Five dogs improved neurologically and had a good long-term outcome. Two dogs were euthanatized, 1 because of worsening of neurologic signs and pneumonia, and the other because of herniation of a cervical intervertebral disc 1 month postoperatively, unrelated to the SEE.

CONCLUSION

Dogs with SEE may have a good outcome when treated by surgical decompression and antibiotic administration.

CLINICAL RELEVANCE

SEE should be included in a list of possible causes for dogs with fever, apparent spinal pain, and myelopathy.

VASCULAR ANOMALY CAUSING SUBCLAVIAN STEAL AND CERVICAL MYELOPATHY IN A DOG: DIAGNOSIS AND ENDOVASCULAR MANAGEMENT

A 3-year-old dog with cervical myelopathy resulting from a vascular anomaly is described. Marked intradural-extramedullary spinal cord compression was observed, in association with multilevel ectatic anastomotic radicular arterial branches connecting the left and right vertebral arteries. A nonpatent proximal segment of the right subclavian artery had resulted in compensatory enlargement of the left vertebral artery. Flow within the right vertebral artery was retrograde and fed into the patent distal segment of the right subclavian artery. Multiple imaging techniques including myelography, computed tomography, magnetic resonance imaging, and selective digital angiography were used to document this anomaly. To reduce spinal cord compression the largest collateral vessel was embolized without complication. Good clinical response was observed within 6 weeks and improved clinical neurologic function was maintained at the time of a 12-month re-evaluation.

The effects of free fat graft or cellulose membrane implants on laminectomy membrane formation in dogs

The purpose of this study was to determine the effect of cellulose membrane or free fat grafts (FFG) on laminectomy membrane (LM) formation. Eighteen dogs were randomly divided into three groups of six dogs. All dogs underwent a modified dorsal laminectomy on T(13)-L(1). The laminectomy defect was left uncovered in the control group but either a FFG or a cellulose membrane implant was provided in the other two groups. The dogs were evaluated through neurological examination, myelography, macroscopic roundness index of spinal cord and histological evaluations of epidural fibrosis and spinal cord. The results showed a significant difference between the control and the FFG group, with the FFG causing neurological deficits and spinal cord compression as assessed by the roundness index of the spinal cord. Both FFG and cellulose membrane were partially effective in preventing LM formation. The use of FFG was associated with a high rate of significant neurological complications and spinal cord lesions.

Myelopathy caused by a histiocytic sarcoma in a cat

An eight-year-old, female spayed, domestic shorthair cat presented with a three-week history of progressive general proprioceptive ataxia and upper motor neuron paresis of the hindlimbs. Computed tomography revealed a mediastinal mass invading the vertebral canal with the T1 spinal nerve and roots, causing extramedullary compression of the cranial thoracic spinal cord. Histopathological and immunohistochemical studies of the mass during postmortem examination disclosed a neoplasm, later determined to be a poorly differentiated histiocytic sarcoma. Feline histiocytic tumours are rare, with only two prior reports existing in the veterinary literature. This report details a case work-up and reviews the literature on feline histiocytic diseases and tumours affecting the feline spinal

Polyostotic Lymphoma With Vertebral Involvement and Spinal Extradural Compression in a Dog

A 10-year-old, male, mixed-breed dog that developed cervical pain and neurological deficits was diagnosed with primary lymphoma of the second cervical vertebra. The cervical lesion was not surgically resectable. A dorsal cervical hemilaminectomy was performed to provide temporary decompression. The dog had complete pain relief after surgery but was euthanized 6 weeks later with recurrent clinical signs and evidence of lymphoma in the right femur.

Thoracolumbar disc extrusion associated with extensive epidural haemorrhage: a retrospective study of 23 dogs

OBJECTIVES

To describe the clinical features and outcome in dogs suffering from thoracolumbar disc extrusion associated with extensive epidural haemorrhage (DEEH) and treated with extensive hemilaminectomy (from three to seven vertebrae).

METHODS

The records of 23 dogs with surgically confirmed DEEH were reviewed retrospectively.

RESULTS

All cases were characterised by rapid progression to severe neurological dysfunction (grade III, V and VI). Myelography was performed in 21 cases and showed an absence (16 cases) or attenuation (five cases) of contrast medium column along three to seven vertebrae. In two dogs, magnetic resonance imaging was accurate in confirming extradural compression due to disc material and haemorrhage, determining the extent of compression and side of the lesion. All cases were treated surgically with extensive hemilaminectomy involving all the compressed spinal segments. Twenty-one dogs (91 per cent) recovered and regained ambulatory function. Two dogs, without deep pain perception before surgery, did not improve. A two-year follow-up history was available for 15 dogs. Disc extrusion recurred in two dogs (9 per cent), two and 20 months after surgery.

CLINICAL SIGNIFICANCE

Extensive hemilaminectomy can adequately decompress the spinal cord after DEEH and may produce a recovery and recurrence rate similar to thoracolumbar disc extrusion not complicated by extensive epidural haemorrhage.

The therapeutic window for spinal cord decompression in a rat spinal cord injury model

OBJECT

There are no clinically based guidelines to direct the spine surgeon as to the proper timing to undertake decompression after spinal cord injury (SCI) in patients with concomitant stenosis-induced cord compression. The following three factors affect the prognosis: (1) severity of SCI; (2) degree of extrinsic spinal cord compression; and (3) duration of spinal cord compression.

METHODS

To elucidate further the relationship between varying degrees of spinal stenosis and a mild contusion-induced SCI (6.25 g-cm), a rat SCI/stenosis model was developed in which 1.13- and 1.24-mm-thick spacers were placed at T-10 to create 38 and 43% spinal stenosis, respectively. Spinal cord damage was observed after the stenosis-SCI that was directly proportional to the duration of spinal cord compression. The therapeutic window prior to decompression was 6 and 12 hours in the 43 and 38% stenosis-SCI lesions, respectively, to maintain locomotor activity. A significant difference in total lesion volume was observed between the 2-hour and the delayed time(s) to decompression (38% stenosis-SCI, 12 and 24 hours, p < 0.05; 43% stenosis-SCI, 24 hours, p < 0.05) indicating a more favorable neurological outcome when earlier decompression is undertaken. This finding was further supported by the animal's ability to support weight when decompression was performed by 6 or 12 hours compared with 24 hours after SCI.

CONCLUSIONS

Analysis of the findings in this study suggests that early decompression in the rat improves locomotor function. Prolongation of the time to decompression may result in irreversible damage that prevents locomotor recovery.

Prognostic value of magnetic resonance imaging in dogs with paraplegia caused by thoracolumbar intervertebral disk extrusion: 77 cases (2000-2003)

OBJECTIVE

To determine whether magnetic resonance imaging findings in dogs with paraplegia caused by thoracolumbar intervertebral disk extrusion were predictive of clinical outcome.

DESIGN

Retrospective case series.

ANIMALS

77 dogs.

PROCEDURE

Medical records and magnetic resonance images were reviewed; clinical outcome was classified as successful (regained ability to walk with no more than mild neurologic deficits) or unsuccessful (severe neurologic deficits persisted). The prognostic value of magnetic resonance imaging was compared with prognostic value of deep pain perception, duration of clinical signs, and rate of onset of clinical signs.

RESULT

33 (43%) dogs had areas of hyperintensity of the spinal cord greater than or equal to the length of the L2 vertebral body on T2-weighted magnetic resonance images. All 44 dogs without areas of hyperintensity on T2-weighted images had a successful outcome, but only 18 of the 33 (55%) dogs with an area of hyperintensity did. Only 5 of 16 dogs with an area of hyperintensity that had also lost deep pain perception had a successful outcome. The odds ratio for an unsuccessful outcome for a dog with an area of hyperintensity (29.87) was higher than the odds ratio for a dog that had lost deep pain perception (5.24). Duration and rate of onset of clinical signs were not associated with clinical outcome.

CONCLUSIONS AND CLINICAL RELEVANCE

Findings suggest that results of magnetic resonance imaging can be used to predict clinical outcome in dogs with paraplegia caused by intervertebral disk extrusion.

Dysplasia of the caudal vertebral articular facets in four dogs: results of radiographic, myelographic and magnetic resonance imaging investigations

Congenital anomalies of the vertebral column associated with aberrations of one of the primary vertebral ossification centres have been frequently described in the veterinary literature, but clinically significant abnormalities of secondary vertebral ossification centres, particularly involving the caudal articular processes, are much less frequently reported. This paper describes three dogs with aplasia and one dog with hypoplasia of the caudal vertebral articular processes. Thoracolumbar spinal cord compression and ataxia was evident in the three dogs with aplasia but no clinical signs were evident in the dog with hypoplasia. The radiographic appearance was similar in all four cases, with aplasia or hypoplasia of the caudal articular facets at one or more intervertebral joints in the thoracolumbar region. Bone proliferation was evident secondary to an associated degenerative joint disease. Compensatory hyperplasia of the adjacent cranial articular facets and ligamentum flavum protruded into the vertebral canal, resulting in a compressive myelopathy observed by myelography and magnetic resonance imaging.

Treatment of a prolapsed lumbar intervertebral disc in a ferret

A seven-month-old, male ferret had acute paraplegia and radiographs showed signs of disc prolapse between the second and third lumbar vertebrae (L2/3). Hemilaminectomy was performed to decompress the spinal cord. Histological examination revealed that the extradural material was consistent with annulus fibrosus and the L2/3 articular facets were enlarged as a result of bone remodelling. The ferret became ambulatory one month postoperatively. Five months postoperatively, the ferret had normal posture with mild proprioceptive deficits in the pelvic limbs, and fusion of the L2 and L3 vertebral bodies.

RADIOGRAPHIC DIAGNOSIS-PARASPINAL ABSCESS IN A DOG

A two-year-old intact male Brittany Spaniel was admitted for evaluation of progressive spinal pain. Previous treatment had been initiated for suspected lumbosacral intervertebral disk disease, however there was poor response to therapy. On presentation the dog was laterally recumbent and neurological examination revealed hyperesthesia over the lumbar vertebral segments. On survey radiography there was loss of detail in the sublumbar fascial planes and inconclusive lumbar vertebra proliferation. Magnetic resonance (MR) imaging was performed to better evaluate the lumbar spine and surrounding tissues, which revealed extensive paralumbar cellulitis, abscessation and osteomyelitis with extradural compression of the spinal cord. MR imaging allowed delineation of the abscessed area, and distinct visualization of its extension into and involvement of the surrounding tissues including muscle, fat, and retroperitoneal structures. In this case, MR imaging was instrumental in defining the extent of the infection and determining whether medical or surgical management of the diseased tissue was necessary. If available, MR may be the imaging method of choice for evaluation of paraspinal abscesses yielding a better insight to the spinal structures involved and facilitating medical or surgical intervention.

Aplastic Articular Facets in a Dog With Intervertebral Disk Rupture of the 12th to 13th Thoracic Vertebral Space

A 6-year-old, female spayed Pomeranian was presented with acute hind-limb paraplegia with the presence of deep pain perception and urinary incontinence. Myelography showed a Hansen type I herniation of the12th to 13th thoracic intervertebral space (T12–13). Articular facets of the T12–13 and T13 to first lumbar vertebra (L1) were absent. The spinal cord was decompressed using a bilateral T12–13 modified lateral hemilaminectomy (pediculectomy). The aplastic sites were associated with minimal instability of the vertebral column, and stabilization of the vertebral column was not required. Familiarity with this condition is important, because articular facet aplasia may cause vertebral instability and may require an adjusted surgical approach or vertebral reduction and fusion following decompression.

Paresis secondary to an extradural hematoma in a Sumatran tiger (Panthera tigris sumatrae)

A 15-yr-old female Sumatran tiger (Panthera tigris sumatrae) was presented to the Boren Veterinary Medical Teaching Hospital at Oklahoma State University with a 3-wk history of progressive hind limb weakness. Neurologic evaluation was limited to review of videotape that demonstrated weakness and ataxia with conscious proprioceptive deficits of the tiger's pelvic limbs. Spinal radiography demonstrated disc space narrowing, and myelography demonstrated a large extradural compressive lesion at the level of L2-3. Computed tomography did not reveal bone involvement. Surgery was performed to decompress the spinal cord and obtain a definitive diagnosis. A right hemilaminectomy was performed after a dorsal approach to the lumbar spine. Histologic examination of the mass revealed a consolidated extradural spinal hematoma, presumed to be secondary to intervertebral disc herniation. Despite incomplete resection of the mass and plastic deformation of the spinal cord, the tiger returned to normal ambulation within 3 wk of surgical decompression.

Metastatic anal sac adenocarcinoma in a dog presenting for acute paralysis

A 4-year old, female spayed terrier was referred for hind end paresis that rapidly progressed to paralysis. Spinal radiographs revealed vertebral collapse and bony lysis. Myelography confirmed spinal cord compression and surgical exploration found an extradural soft tissue mass. Metastatic anal sac adenocarcinoma was diagnosed at postmortem examination.

Cervical spondylomyelopathy (wobbler syndrome) in the Boerboel

The Boerboel is a South African large-breed dog resembling a Bullmastiff. The records of Onderstepoort Veterinary Academic Hospital were searched for dogs that had presented, between 1998 and 2003, with symptoms indicative of wobbler syndrome and had undergone survey radiographic and myelographic studies. Ten cases fitted the inclusion criteria. Dogs presented within the first 2 years of life, often with acute onset of symptoms. All presented with pelvic limb and 6 with concomitant thoracic limb ataxia or paresis. Treatment varied and included none (4), prednisolone (2), and dorsal laminectomy (2). Two dogs were euthanased at the time of diagnosis. The breed appears to be affected with a form of spondylomyelopathy that comprises bony malformation of cervical and/or thoracic vertebrae. In 8 dogs, malformations were evident on survey radiographs and were characterised by enlarged, irregular articular facets and associated medial deviation of the pedicles. These changes resulted in axial compression of the spinal cord best seen on ventrodorsal or dorsoventral myelographic studies. Multiple vertebrae were affected in some dogs and lesions were not confined to the caudal area of the cervical spine. Three dogs were alive and without symptoms at follow-up. Four were euthanased as a result of the disease and 1 died as a result of post-operative complications. Two additional dogs presenting with wobbler clinical signs are also described. One had medial deviation of the T5 and T6 caudal pedicles and 1 dog suffered from multiple cervical articular facet synovial cysts.

Thoracolumbar spinal cord compression due to vertebral process degenerative joint disease in a family of Shiloh Shepherd dogs

Five young Shiloh Shepherd Dogs (4 males and 1 female) related by a common sire were studied because of progressive pelvic limb weakness and incoordination. All dogs had a spastic paraparesis and pelvic limb ataxia consistent with an upper motor neuron and general proprioceptive lesion between spinal cord segments T3 and L3. Proliferative lesions involving one or more of the articular processes from the 11th thoracic vertebrae to the 2nd lumbar vertebra were observed on radiographs of the thoracolumbar vertebrae. Dorsal compression of the spinal cord was identified during imaging studies at these sites. Abnormalities of the synovial joints and bony proliferation of the involved articular processes were identified at postmortem examination in 2 dogs. The articular processes and associated vertebral arches protruded into the vertebral canal, indenting the dorsal surface of the spinalcord. Degenerative joint disease (DJD) was identified histologically. A compressive myelopathy was diagnosed in the spinal cord. These dogs were affected by a compressive myelopathy as a consequence of vertebral process DJD that likely has a geneticcomponent. The DJD could have been caused by a primary vertebral malformation or an injury to the processes at a young age causing malarticulation.

Effects of corticosteroid and electroacupuncture on experimental spinal cord injury in dogs

The aim of this study is to investigate the effects of electroacupuncture, corticosteroid, and combination of two treatments on ambulatory paresis due to spinal cord injury in dogs by comparing therapeutic effects of electroacupuncture and corticosteroid. Spinal cord injury was induced in twenty healthy dogs (2.5-7 kg and 2-4 years) by foreign body insertion which compressed about 25% of spinal cord. There was no conscious proprioception, no extensor postural thrust, and ambulatory. Dogs were divided into four groups according to the treatment; corticosteroid (group A), electroacupuncture (group B), corticosteroid and electroacupuncture (group AB), and control (group C). Neurological examination was performed everyday to evaluate the spinal cord dysfunction until motor functions were returned to normal. Somatosensory evoked potentials (SEPs) were measured for objective and accurate evaluations. The latency in measured potentials was converted into the velocity for the evaluation of spinal cord dysfunctions. Pain perceptions were normal from pre-operation to 5 weeks after operation. Recovery days of conscious proprioception in groups A, B, AB, and C were 21.2+/-8.5 days, 19.8+/-4.3 days, 8.2+/-2.6 days, and 46.6+/-3.7 days, respectively. Recovery days of extensor postural thrust in group A, group B, group AB, and group C were 12.8+/-6.8 days, 13.8+/-4.8 days, 5.4+/-1.8 days, and 38.2+/-4.2 days, respectively. There were no significant differences between group A and group B. However, recovery days of group AB was significantly shorter than that of other groups and that of group C was significantly delayed (p<0.05). Conduction velocities of each group were significantly decreased after induction of spinal cord injury on SEPs (p<0.05) and they showed a tendency to return to normal when motor functions were recovered. According to these results, it was considered that the combination of corticosteroid and electroacupuncture was the most therapeutically effective for ambulatory paresis due to spinal cord injury in dogs.

[Clinical findings in four cattle with abscesses in the cervical vertebrae]

The purpose of this paper was to describe the clinical findings in four cattle with abscesses in the cervical vertebrae. In all of the animals there was generalized ataxia and normal behaviour, mentation and cranial nerve function. All animals had marked difficulty rising and had generalized ataxia. The most important haematological and biochemical findings were a mildly increased concentration of plasma protein in all animals and a markedly increased fibrinogen concentration in two animals. A sample of cerebrospinal fluid (CSF) was collected from three animals. The protein content was mildly increased in the CSF samples of two animals. Based on the clinical findings, a tentative diagnosis of central nervous system disease with localisation in the neck region was made in all of the animals. Due to a poor prognosis, all of the animals were slaughtered. Postmortem examination revealed abscesses in the region of C3 to C6, which had resulted in extramedullary compression of the spinal cord. The abscesses varied in diameter from 2 to 8 cm.