Congenital kyphosis secondary to lumbar vertebral hypoplasia causing paraparesis in a Friesian foal

A 5‐day‐old Friesian colt was presented with a history of severe bilateral pelvic limb weakness since birth. Clinical examination revealed a painful dorsal deviation of the spinous processes of the lumbar vertebrae, pelvic limb paraparesis and grade 4/5 ataxia. Radiographic examination revealed kyphosis due to hypoplasia and malformation of the 5 lumbar vertebrae present. At myelography performed immediately after euthanasia, dorsal deviation of the myelographic contrast column was demonstrated at the level of T18–L4 with suspected spinal cord compression noticeable at L1. There was no lateral deviation of the spinal cord or scoliosis of the vertebrae visible.     

Lumbosacral intervertebral disk disease in six cats

Medical records of six cats diagnosed with lumbosacral intervertebral disk disease were reviewed. Clinical signs included reluctance to jump, low tail carriage, elimination outside the litter box, reluctance to ambulate, pelvic-limb paresis, urinary incontinence, and constipation. All cats had lumbosacral hyperpathia on palpation. Computed tomography in four cats revealed evidence of extradural spinal cord compression at the seventh lumbar (L(7)) to first sacral (S(1)) vertebral interspace. Compression was confirmed via myelography in three of these four cats, with confirmation in the fourth cat at the time of decompressive laminectomy. Each of the six cats underwent dorsal decompressive laminectomy at the L(7) to S(1) interspace. Postoperative clinical follow-up lasted 3 to 35 months, with most cats having excellent outcomes.     

Lameness of the hindlimbs of the cat

About six to seven per cent of cats presented at the clinic show neurological signs. The largest group consists of traumatized cats. A complete neurological examination is essential for localizing the lesion and establishing a prognosis. Differential diagnosis for paraparesis/paraplegia of pelvic limbs in cats are discussed. Cats are demonstrated which had spinal cord trauma, disc protrusion, aortic thromboembolism and lumbosacral stenosis and the importance of the evaluation of x-rays, cerebrospinal fluid examination and myelography is stressed.     

Protozoan encephalomyelitis causing pelvic limb paresis in a yearling sheep

A pelvic limb paresis of 6 weeks duration in a yearling sheep resulted from protozoan encephalomyelitis involving the spinal cord at the thoracolumbar junction. An elevated lumbosacral cerebrospinal fluid protein concentration but normal cisternal cerebrospinal fluid protein concentration indicated the presence of a thoracolumbar inflammatory lesion resulting in cord compression which obstructed the rostral flow of the cerebrospinal fluid. Under general anaesthesia, myelography at the lumbo-sacral site demonstrated blockage to the rostral flow of contrast medium at T₁₃L₁. At necropsy, there were no gross pathological changes at T₁₃/L₁, but histopathology revealed non-tract specific lymphocytic perivascular cuffing, axonal swelling and oedema in the spinal cord, characteristic of a protozoa1 encephalomyelitis. No parasites were detected in the multiple spinal cord sections examined but immunocytochemistry identified antigens cross-reactive with Sarcocystis spp. antigens in glial cells in these lesions.     

Spinal meningeal sarcoma in a rottweiler puppy

An 11-week-old rottweiler puppy was presented for evaluation of progressive paraparesis, urinary and faecal incontinence. Radiography and myelography revealed widening of the vertebral canal and remodelling of several lumbar vertebrae associated with an intramedullary spinal mass. Magnetic resonance imaging revealed an extensive, heterogeneous mass involving the lumbosacral spinal cord. Histopathological examination indicated a meningeal sarcoma with very varied cytological architecture.     

Extradural spinal juxtafacet (synovial) cysts in three dogs

Three dogs were presented for investigation of spinal disease and were diagnosed with extradural spinal juxtafacet cysts of synovial origin. Two dogs that were presented with clinical signs consistent with pain in the lumbosacral region associated with bilateral hindlimb paresis were diagnosed using magnetic resonance imaging. Both cysts were solitary and associated with the L6-7 dorsal articulations; both the dogs had a transitional vertebra in the lumbosacral region. A third dog that was presented with progressive paraparesis localised to T3-L3 spinal cord segments and compression of the spinal cord at T13-L1 was diagnosed using myelography. A solitary multiloculated cyst was found at surgery. Decompressive surgery resulted in resolution of the clinical signs in all three dogs. Immunohistological findings indicated that one to two layers of vimentin-positive cells consistent with synovial origin lined the cysts.     

Protozoan encephalomyelitis causing pelvic limb paresis in a yearling sheep

A pelvic limb paresis of 6 weeks duration in a yearling sheep resulted from protozoan encephalomyelitis involving the spinal cord at the thoracolumbar junction. An elevated lumbosacral cerebrospinal fluid protein concentration but normal cisternal cerebrospinal fluid protein concentration indicated the presence of a thoracolumbar inflammatory lesion resulting in cord compression which obstructed the rostral flow of the cerebrospinal fluid. Under general anaesthesia, myelography at the lumbo-sacral site demonstrated blockage to the rostral flow of contrast medium at T13/L1. At necropsy, there were no gross pathological changes at T13/L1, but histopathology revealed non-tract specific lymphocytic perivascular cuffing, axonal swelling and oedema in the spinal cord, characteristic of a protozoal encephalomyelitis. No parasites were detected in the multiple spinal cord sections examined but immunocytochemistry identified antigens cross-reactive with Sarcocystis spp. antigens in glial cells in these lesions.     

Spinal Epidural Abscess in Two Calves

Objective— To report clinical signs, diagnostic and surgical or necropsy findings, and outcome in 2 calves with spinal epidural abscess (SEA). Study Design— Clinical report. Animals— Calves (n=2). Methods— Calves had neurologic examination, analysis and antimicrobial culture of cerebrospinal fluid (CSF), vertebral column radiographs, myelography, and in 1 calf, magnetic resonance imaging (MRI). A definitive diagnosis of SEA was confirmed by necropsy in 1 calf and during surgery and histologic examination of vertebral canal tissue in 1 calf. Results— Clinical signs were difficulty in rising, ataxia, fever, apparent spinal pain, hypoesthesia, and paresis/plegia which appeared 15 days before admission. Calf 1 had pelvic limb weakness and difficulty standing and calf 2 had severe ataxia involving both thoracic and pelvic limbs. Extradural spinal cord compression was identified by myelography. SEA suspected in calf 1 with discospondylitis was confirmed at necropsy whereas calf 2 had MRI identification of the lesion and was successfully decompressed by laminectomy and SEA excision. Both calves had peripheral neutrophilia and calf 2 had neutrophilic pleocytosis in CSF. Bacteria were not isolated from CSF, from the surgical site or during necropsy. Calf 2 improved neurologically and had a good long‐term outcome. Conclusion— Good outcome in a calf with SEA was obtained after adequate surgical decompression and antibiotic administration. Clinical Relevance— SEA should be included in the list of possible causes of fever, apparent spinal pain, and signs of myelopathy in calves.     

Thoracic vertebral chordoma in a domestic ferret (Mustela putorius furo).

A castrated adult male 1.0-kg domestic ferret (Mustela putorius furo) was referred for evaluation of a mass of >5 mo duration that was associated with the thoracic spine. The ferret had motor dysfunction and no conscious proprioception or pain perception in either hind limb. Segmental reflexes were present. Survey radiography, myelography, and magnetic resonance imaging showed a mass involving the ninth and 10 thoracic vertebrae and compressing the spinal cord. Decompressive surgery was performed, but clinical signs persisted. A diagnosis of chordoma was made using histopathology and immunohistochemistry. This is the first reported case of a chordoma involving the thoracic vertebrae in a domestic ferret.     

METRIZAMIDE MYELOGRAPHY IN FIVE DOGS AND TWO CATS WITH SUSPECTED SPINAL CORD NEOPLASMS

Metrizamide myelography was used in five dogs and two cats with signs of spinal cord disease. The history, clinical signs, cerebrospinal fluid examination, and myelography supported a presumptive diagnosis of spinal cord neoplasia in all seven animals. Myelography demonstrated a deviation of the subarachnoid space in each of them. Five of the animals had an expansile intramedullary spinal cord lesion causing thinning and peripheral deviation of the subarachnoid space. Two had extramedullary lesions causing a central deviation of the subarachnoid space. Spinal cord tumors in six of the seven animals were confirmed by necropsy or surgical excision and histopathologic examination. In the seventh animal, a spinal cord fungal grapuloma was diagnosed by necropsy.     

Degenerative spinal disease in large felids.

Degenerative spinal disorders, including intervertebral disc disease and spondylosis, seldom occur in domestic cats. In contrast, a retrospective study of 13 lions (Panthera leo), 16 tigers (Panthera tigris), 4 leopards (Panthera pardis), 1 snow leopard (Panthera uncia), and 3 jaguars (Panthera onca) from the Knoxville Zoo that died or were euthanatized from 1976 to 1996 indicated that degenerative spinal disease is an important problem in large nondomestic felids. The medical record, radiographic data, and the necropsy report of each animal were examined for evidence of intervertebral disc disease or spondylosis. Eight (three lions, four tigers, and one leopard) animals were diagnosed with degenerative spinal disease. Clinical signs included progressively decreased activity, moderate to severe rear limb muscle atrophy, chronic intermittent rear limb paresis, and ataxia. The age at onset of clinical signs was 10-19 yr (median = 18 yr). Radiographic evaluation of the spinal column was useful in assessing the severity of spinal lesions, and results were correlated with necropsy findings. Lesions were frequently multifocal, included intervertebral disc mineralization or herniation with collapsed intervertebral disc spaces, and were most common in the lumbar area but also involved cervical and thoracic vertebrae. Marked spondylosis was present in the cats with intervertebral disc disease, presumably subsequent to vertebral instability. Six of the animals' spinal cords were examined histologically, and five had acute or chronic damage to the spinal cord secondary to disc protrusion. Spinal disease should be suspected in geriatric large felids with decreased appetite or activity. Radiographic evaluation of the spinal column is the most useful method to assess the type and severity of spinal lesions.     

Chiari‐like malformation in two cats

Two male, neutered, domestic, shorthaired cats were evaluated for progressive paresis and ataxia. Neurological examinations suggested a spinal cord lesion in each case. Complete blood examination and cerebrospinal fluid analysis were unremarkable in both cats. MRI revealed malformation of the occipital bone with herniation of the cerebellar vermis through the foramen magnum but without syringomyelia. Chiari‐like malformation was suspected in both patients. MRI repeated one year later in both cats because of progression of clinical signs yielded the same findings as the initial scans. Foramen magnum decompression in one cat was associated with resolution of clinical signs.     

Disseminated infection with Neospora caninum in a ten-year-old dog

Naturally-occurring neosporosis with multiple organ involvement was identified in a 10-year-old neutered male Basset hound dog. Clinical signs were first noticed 3 weeks prior to referral and consisted of crouched stance and mild pelvic limb ataxia. Dexamethasone administration had provided transient improvement. On presentation to the teaching hospital, clinical signs included depression, pelvic limb ataxia, inability to stand without assistance, and pain on deep palpation of the cervical and lumbar vertebral column. Lesions were found in the myocardium, liver, spleen, adrenal glands, brain, and spinal cord. Tachyzoites of Neospora caninum were found in the myocardium and adrenal glands. Organisms stained with anti-Neospora caninum, but not to anti-Toxoplasma gondii serum in an immunohistochemical test.     

Spinal cord effects from lumbar myelographic injection technique in the dog

To characterize spinal cord effects of needle placement using lumbar puncture myelography technique, lumbar puncture was performed in 5 dogs and computed tomography images of the spinal column were acquired in the transverse plane at the level of the puncture site after contrast injection and both before and after needle removal. The spinal cords were punctured during needle placement and parenchymal contrast enhancement was present in 4 of 5 dogs. Although no dogs exhibited overt neurological abnormalities following computed tomographic imaging, hemorrhage, gliosis and axonal degeneration were confirmed microscopically in all subjects. These results suggest that spinal cord morbidity is induced when lumbar myelography is performed using currently accepted technique.     

Fibrocartilaginous emboli in a tayra (Eira barbara): a case report.

An 8-yr-old male tayra (Eira barbara) was presented with acute onset of pelvic limb paralysis. Radiography was unremarkable. Neurologic examination showed signs consistent with an intramedullary lesion between the second thoracic and fifth lumbar spinal cord segments. The animal's condition did not improve after 4 days of aggressive glucocorticoid therapy, and euthanasia was performed. Histologic examination of the spinal cord showed amorphous emboli suggestive of cartilaginous fragments within spinal veins. A diagnosis of fibrocartilaginous emboli was made, the first known case in a mustelid.     

Cervical intervertebral disc protrusion in two horses

Two horses with ataxia of all four limbs were found to have cervical intervertebral disc protrusion. Severe pelvic limb ataxia, proprioceptive deficits and spasticity were present in both horses with similar but less severe signs in the thoracic limbs. Cerebrospinal fluid analysis was within normal limits. Metrizamide myelography allowed definitive diagnosis in one case when a compression of the spinal cord was demonstrated at the level of the second intervertebral space. In the second case, an intervertebral disc protrusion between cervical vertebrae 6 and 7 was found at necropsy. Fiber degeneration with poor myelin staining characterized the spinal cords histologically.     

Fluorine‐18 fluorodeoxyglucose positron emission tomography imaging exhibits increased SUVmax at the level of the spinal intumescence in normal dogs

Positron emission tomography (PET) imaging utilizing fluorine‐18 labeled fluorodeoxyglucose is a relatively new imaging modality in veterinary medicine that is becoming more common for oncological staging and for musculoskeletal imaging. Thus, it is important to identify the normal variations on PET imaging that may be mistaken for pathology. Variation in standardized uptake values (SUVmax) have been anecdotally identified in the spinal cord of dogs undergoing fluorodeoxyglucose (FDG) PET–CT examinations for oncological staging, with notable increase in SUVmax values identified in the region of the cervical and lumbar spinal intumescences. The aim of this retrospective, analytical study was to compare the SUVmax values at four different locations throughout the spinal cord (C3, C5‐T1, T13, and L3‐S1) of a group of dogs with no evidence of neurologic disease and compare those findings to histologic specimens from dogs euthanized for unrelated disease. SUVmax values were significantly higher at the cervical and lumbar intumescences in comparison to the control regions (P < .0001 and P < .0001, respectively). Neuronal count and spinal cord gray matter area were also significantly greater at the cervical and lumbar intumescences (neuronal count P = .0025 and P = .0001; area P = .0004 and P = .0009, respectively) while overall neuronal density was lower (P = .003 and P = .028, respectively). We presume the increased SUVmax values at the spinal cord intumescences are the result of overall increased neuron count, increased proportion of gray matter, and increased spinal cord gray matter area. These findings will aid in the interpretation of future PET–CT studies and hopefully prevent the misdiagnosis of spinal cord disease in normal canines.     

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.     

Lightning injury in an outdoor swine herd.

Three pigs, weighing 63 kg-70 kg each, from a group of 8 pigs in an outdoor pen that was struck by lightning were necropsied. All 3 pigs presented with hind limb paralysis. The only lesions identified were multiple fractures of the last (seventh) lumbar vertebral body and first sacral vertebral segment, with dorsal displacement of the sacrum and transection of the distal spinal cord and spinal nerves. Hemorrhages extended from the fracture sites into muscles immediately surrounding the lumbosacral junction and retroperitoneally into the pelvic cavity. These hemorrhages were not clearly visible until the pelvic region was dissected. Lesions commonly found in human lightning-strike victims were not present in these pigs. Because vertebral fractures may be the only lesions and may be grossly subtle in heavily muscled pigs, careful pelvic and vertebral dissection is recommended in cases of suspected lightning strike and electrocution.     

Partial lateral corpectomy of the thoracolumbar spine in 51 dogs: assessment of slot morphometry and spinal cord decompression

Objective: To report slot morphometry, degree of spinal decompression, and factors influencing decompression after partial lateral corpectomy (PLC) of the thoracolumbar spine in dogs with intervertebral disc disease. Study Design: Case series. Animals: Dogs (n=51) with predominantly ventrally located spinal cord compression. Methods: PLC (n=60) were performed. Spinal cord compression was determined by computed tomographic (CT) myelography (n=46), myelography (n=2) or magnetic resonance imaging (n=3). Postsurgical CT images were used to evaluate slot dimensions and orientation, and spinal cord decompression. The influence of age, body weight, breed, breed type (chondrodystrophic, nonchondrodystrophic), disc location, lateralization and mineralization, presurgical compression, slot morphometry, and surgeon on degree of decompression were evaluated. Results: Mean slot depth was 64.1% of vertebral body width; mean height, 43.0% of vertebral body height; mean cranial extension, 29.5%; median caudal extension, 22.0% vertebral body length; mean angulation from horizontal, 6.3°. Decompression was satisfactory in 90% of sites after PLC (58% complete, 32% good). None of the analyzed factors significantly influenced decompression. All lumbar spine PLC resulted in complete or good decompression compared with 83% after thoracic PLC (P=.052). Deeper slots tended to allow more complete decompression (P=.058). Conclusions: Thoracolumbar PLC results in satisfactory decompression in most cases with a better outcome in the lumbar spine than the thoracic spine. Achieving a slot depth equal to 2/3 of vertebral body width might facilitate complete decompression.