Radiculomeningomyelitis due to Halicephalobus gingivalis in a horse

An adult horse was euthanatized following a clinical diagnosis of cauda equina neuritis. Significant gross postmortem and histopathologic findings were limited to the sacral spinal cord and cauda equina. The sacral spinal cord, meninges, and spinal nerve roots were expanded and partially effaced by sclerosing granulomatous inflammation with necrosis. The lesion contained numerous nematode larvae and fewer adults with a rhabditiform esophagus having a corpus, isthmus, and valved bulb. Female nematodes were amphidelphic and didelphic with reflexed ovaries. These morphologic features confirm Halicephalobus gingivalis as a novel cause of clinical signs in this case of cauda equina neuritis.     

L7-S1 fixation-fusion for treatment of cauda equina compression in the dog

The L7-S1 fixation-fusion technique for treatment of cauda equina compression was performed on 14 dogs, 13 of which were 6 years old or older, were severely lame, and had ventral bridging spondylitis at the L7-S1 vertebrae. One dog, 3 months old, had a congenital malformation of the L7 vertebra. The principles of the L7-S1 fusion technique were to expand the L7-S1 intervertebral foramina and spinal canal, remove pressure on the nerve roots, and provide stability to the L7-S1 vertebrae. This technique appeared to be applicable clinically for restoring normal function and activity to dogs with cauda equina compression.     

Neuritis of the cauda equina in a dog

This study presents the first case report of neuritis of the cauda equina in a dog, including characterisation of the inflammatory infiltrate. The dog in question, a 6-year-old Welsh springer spaniel, was presented with flaccid tail and faecal and urinary incontinence. The histological lesions included severe mononuclear cell infiltration of the nerve roots of the cauda equina and of the lumbar nerve roots. The infiltrate was composed of large numbers of T-lymphocytes and B-lymphocytes and small numbers of macrophages. Polymerase chain reactions of brain and spinal tissues were positive for Neospora caninum.     

Synovial cysts associated with cauda equina syndrome in two dogs

OBJECTIVE: To report synovial cysts associated with cauda equina syndrome in 2 dogs. STUDY DESIGN: Clinical cases. ANIMALS: Two German Shepherd dogs. METHODS: After magnetic resonance imaging detection, cysts were surgically removed via dorsal laminectomy. RESULTS: Six and 8 months after surgery, both dogs were free of clinical signs and no pain was elicited on lumbosacral joint manipulation. CONCLUSION: Although described in dogs, cysts at the lumbosacral joint might cause compression of the cauda equina nerve roots. Radical excision of the cyst capsule can result in resolution of clinical signs. CLINICAL RELEVANCE: Synovial cysts should be considered in the differential diagnosis of dogs with cauda equina compression syndrome when lumbosacral degenerative joint disease is present.     

Cauda equina syndrome in the dog: Radiographic evaluation

Dogs with clinical signs typical of cauda equina syndrome require careful evaluation to determine the cause of the disease as this strongly influences choice of treatment. Possible aetiologies include congenital or developmental, inflammatory, traumatic, neoplastic, and degenerative lesions that may involve vertebrae, vertebral joints, intervertebral discs, spinal cord, spinal nerves, or meninges. It must be determined whether clinical signs are due to musculoskeletal or neurological disease before performing special radiographic procedures. Non-contrast radiography permits false-positive diagnosis of obvious degenerative changes involving the L-S disc that may be without clinical signs or permits a false-negative diagnosis due to the failure to appreciate soft tissue lesions not seen radiographically. Special radiographic techniques are recommended and include: (1) stress radiography, (2) discography, and (3) epidural myelography. Evaluation of the results of these studies assists in determining the cause of the cauda equina syndrome and the type of therapy required.     

Diagnosis of Cauda Equina Abnormalities By Using Electromyography, Discography, and Epidurography in Dogs

Electromyography (EMG), L7-S1 discography and epidurography were investigated in 15 dogs with clinical signs of cauda equina dysfunction and in 7 control dogs without such clinical signs. Electromyography of paraspinal and pelvic limb muscles was done in 13 of 15 affected dogs. An L7-S1 discogram followed by an epidurogram was performed in all 22 dogs using 20% iopamidol. Results of discograms, epidurograms, and gross necropsy examinations were normal in six of seven control dogs. The one dog in which these studies were abnormal had a mild L7-S1 disc protrusion that did not result in nerve root compression at necropsy. Electromyographic analysis was 100% accurate in predicting the presence or absence of cauda equina disease. None of the results of discograms were falsely negative. Twelve of 15 discograms in clinically affected dogs indicated dorsal disc protrusion, but 2 of these protrusions were found to be noncompressive at surgery (13% error). Abnormal epidurograms occurred in 9 of 15 clinically affected dogs. There was one false positive and two false negatives (20% error). Electromyography was a sensitive screening technique for the presence of cauda equina disease. Discography may be more sensitive for detection of L7-S1 disc protrusion than epidurography. An abnormal radiographic contrast study of the cauda equina may only be useful when combined with an abnormal EMG.     

Intramedullary Spinal Glioblastoma in a Cat, Presented as a Cauda equina Syndrome

A ten year old castrated male domestic short haired cat, was presented with clinical signs related to the cauda equina. The results of the neurological examination, diagnostic procedures, and clinical course are presented. At necropsy a glioblastoma of the caudal spinal cord was present. The difficulties in distinguishing between neoplasms arising in the cauda equina and the caudal spinal cord are discussed. A comparative discussion of the cauda equina syndrome is presented.     

Asymmetric lumbosacral transitional vertebra and subsequent disc protrusion in a cocker spaniel

A 10-year-old cocker spaniel bitch presented with severe lumbosacral pain and acute onset left pelvic limb lameness. A diagnosis of asymmetric lumbosacral transitional vertebra with disc protrusion at L6-L7 was made by computed tomography. The cauda equina and left L6 nerve root were surgically decompressed with a dorsal laminectomy and lateral foraminotomy, which led to rapid resolution of the clinical signs.     

Occurrence of Unilateral Posterior Polyneuritis in an 8-year-old Crossbred Mare

An 8-year-old Thoroughbred Turkoman crossbred mare was examined for right pelvic limb paresis and ataxia. The signs had been progressing through time. Neurological examinations revealed a gait deficit, right pelvic limb gluteal muscles atrophy, skin hypalgesia around the tail, perineum, and right pelvis. Hyperesthesia was found in the margins of anesthetic areas. Hypotonic anal sphincter and flaccid tail were also evident. Fecal and urinary retention were revealed by rectal palpation. At necropsy, the affected nerve roots in right lumbar, sacral vertebrae, as well as cauda equina were found to be significantly thickened and fibrotic with adhesions to the related vertebral bodies. Histopathological examinations confirmed the diagnosis of polyneuritis in this mare.     

A SACRAL LESION RESEMBLING OSTEOCHONDROSIS IN THE GERMAN SHEPHERD DOG

More than 30% (21 of 65) of German Shepherd dogs with clinical signs of cauda equina compression had radiographic and pathologic abnormalities compatible with osteochondrosis of the sacral endplate. Most of these dogs had a defect in the dorsal part of the sacral endplate and a detached bone fragment in the vertebral canal. Similar lesions were also found in growing and young adult dogs without clinical signs. The dogs with clinical signs of cauda equina compression also had severe degenerative disc disease with protrusion of the lumbosacral disc and compression of the cauda equina, suggesting that the signs of cauda equina compression more likely were related to the secondary degenerative changes (disc protrusions) rather than the primary disease. Clinically normal German Shepherds with sacral osteochondrosis usually were younger than 18 months, the dogs with cauda equina compression and sacral osteochondrosis older than 18 months (mean age 4.8 years). On the average, these dogs were two years younger as compared to dogs with cauda equina compression without sacral osteochondrosis. Male dogs are more often affected than females (5:1). There is a breed predisposition: in dogs other than German Shepherds, osteochondrosis of the sacral endplate seems to be extremely rare.     

Diagnosis of lumbosacral intervertebral disc disease and protrusion in a horse using ultrasonographic evaluation and computed tomography

This case report describes the clinical presentation, diagnostic imaging modalities, treatment and post mortem evaluation of lumbosacral intervertebral disc protrusion in a mature Quarter Horse gelding 10 days after initial signs were noted. Grade 3 hindlimb ataxia, conscious proprioceptive deficits, urinary and faecal incontinence were present, which did not improve with anti‐inflammatories, antimicrobial therapy, corticosteroids, antioxidant therapy, cold‐laser therapy or electroacupuncture. Imaging modalities utilised ante mortem were computed radiography, transcutaneous and transrectal ultrasonography. Transrectal ultrasonography yielded findings highly suggestive of lumbosacral intervertebral disc protrusion and due to the lack of improvement and a poor prognosis, the horse was humanely subjected to euthanasia. Post mortem computed tomography, necropsy and histopathological evaluation confirmed lumbosacral intervertebral disc disease and protrusion into the spinal canal with subsequent impingement of the spinal nerve roots. Lumbosacral intervertebral disc protrusion as a clinical disease in the horse has not been previously described and should be included as a differential diagnosis in cases with acute hindlimb ataxia, proprioceptive deficits, and urinary and faecal incontinence.     

Paraparesis as initial manifestation of a Prototheca zopfii infection in a dog

A case of protothecosis causing non‐ambulatory paraparesis in a dog without clinical evidence of disseminated infection is described. A five‐year‐old female Labrador retriever was referred with a 10‐day history of progressive non‐ambulatory paraparesis and lumbar pain as the only physical and neurological abnormalities. Lumbar myelography revealed severe extradural spinal cord compression extending from L4 to L7 vertebrae, and a right hemilaminectomy was performed. Surgical findings included an adherent whitish hard ill‐defined mass. Cytology and biopsy results disclosed the presence of algae enclosed in a matrix of chronic inflammatory infiltrate. Culture confirmed the presence of Prototheca species. Neurological improvement occurred within a month, and the dog received antifungal treatment without evidence of clinical disseminated disease for 6 months, but died after a generalised tonic–clonic seizure. Post‐mortem examination revealed multiple foci of inflammatory granulomatous infiltrate and algae‐like structures in the brain, lumbar intumescence and cauda equina. Prototheca zopfii was identified using molecular biology methods.     

Pathological features of ganglioradiculitis (sensory neuropathy) in two dogs

Canine ganglioradiculitis (sensory neuropathy) was examined pathologically in two dogs (dog Nos. 1 and 2). The affected dogs had 1 and 2 years clinical courses from the onset, respectively. As common clinical signs, both cases showed progressive ataxia, difficulty in prehending food, visual deficit, and several sensory abnormalities. Gross observation after tissue fixation revealed whitish discoloration in the dorsal column of the spinal cords. The histological lesions were mainly distributed in the spinal dorsal roots, ganglions, and dorsal columns. In the spinal dorsal roots and ganglions, there were striking myelin loss, mild infiltration of mononuclear cells, and proliferation of small spindle cells. In the dorsal funiculus, there were moderate to severe diffuse myelin-loss and axonal degeneration. Immunohistochemistry for substance P (SP) revealed marked reduction of SP-immunopositive granules in the spinal substantia gelatinosa of affected dogs. By immunohistochemistry, CD3-positive cells were observed in the dorsal roots of dog No. 2, while CD3-positive cells were rare in those of dog No. 1. In the spinal ganglion of dog No. 1 there were many CD3- and MHC class II-positive cells. By indirect immunofluorescence assay using sera from affected dogs, no autoantibodies against canine nerve tissues were detected. The clinicopathological features of the present cases are almost consistent with those in previous reports of canine sensory neuropathies, while the etiology remains unclear.     

Surgical treatment of sacral fracture in a horse

An 8-year-old Arabian stallion had signs of severe tailhead pruritus and slowly progressive loss of tail tone for 3 months. Palpation per rectum and radiography of the sacrocaudal region revealed a transverse, ventrally displaced fracture of the caudal portion of the sacrum. Surgical decompression and tail amputation resulted in complete recovery of athletic and reproductive function. Evidence of cauda equina neuritis was not seen on histologic examination of nerve roots obtained at surgery.     

Cauda equina neuritis: a chronic idiopathic polyneuritis in two horses

Two cases of cauda equina neuritis are compared and contrasted. Neurological deficits of the tail and perineum were noted and functional deficits were seen in gait, urination, defecation and cranial nerve function. Lesions consisted of nonsuppurative inflammation of the nerve trunks and proliferation of the perineurium of the cauda equina. Cranial nerve involvement in one case supported a diagnosis of polyneuritis equi rather than cauda equina neuritis. The possible etiologies and pathogenesis of this disease are discussed.     

Lumbosacral stenosis and injury of the cauda equina

Idiopathic (congenital) L/S stenosis, acquired (degenerative) L/S stenosis, and traumatic injury to the vertebral column caudal to L6 often produce signs of neurologic dysfunction attributed to compression, displacement, entrapment, or trauma of the cauda equina. Clinical signs vary from animal to animal and depend upon which roots of the cauda equina are involved and the nature of the compromise. An understanding of the anatomy of the area and an appreciation for the functional relationship between the cauda equina and structures innervated are essential for accurate evaluation, workup, diagnosis, treatment, and outcome.     

Progressive neurological signs associated with systemic mastocytosis in a dog

A 9-year-old dog was presented with nonregenerative anaemia and severe thrombocytopenia, diarrhoea, spinal hyperalgesia and progressive hindlimb paresis. A moderately well differentiated cutaneous mast cell tumour (MCT) was removed from the skin of the right elbow along with the enlarged right prescapular lymph node. Due to deterioration of the dog's neurological condition, euthanasia was performed. On necropsy examination, haemorrhage and accumulations of poorly differentiated mast cells were found in the lumbosacral region and cauda equina. This article describes an unusual presentation of systemic mastocytosis and the previously unreported finding of metastasis of mast cells to the spinal cord.     

Measurements on the lumbosacral junction in normal dogs and those with cauda equine compression

Comparative measurements on lateral plain radiographs of the lumbosacral junction in neutral position, in flexion, and in extension, were made of 41 clinically and radiographically normal dogs (21 German shepherd dogs [GSDs], 12 Bernese mountain dogs, eight labrador retrievers) and 58 GSDs with clinical signs of cauda equina compression due to malformation and, or, malarticulation. The comparison of these measurements between sexes, between normal and affected GSDs and between normal GSDs and the two other breeds of dogs showed several statistically significant results. One was that the affected GSDs showed a reduced flexion ability at this junction compared to the normal ones. However, no difference was observed in the degree of sub-luxation of the sacrum between normal and affected GSDs. It was concluded that plain radiographs of the lumbosacral junction in flexion could help in determining a reduced flexion ability, which could be a characteristic of the GSD with cauda equina compression.     

FLEXION-EXTENSION MYELOGRAPHY OF THE CANINE CAUDA EQUINA

The radiographic appearance of the canine dural end-sac and its behavior during flexion and extension of the spine is described in a myelographic study in 22 normal dogs and 26 dogs with cauda equina compression syndrome. In more than 80% of the dogs, the dural sac ended at the level of the sacrum. There were relatively large individual differences in shape and size of the dural end-sac. In contrast, shape, length, position, and diameter of the dural end-sac at the level of the lumbosacral articulation is extremely constant during flexion and extension in normal individuals. In the 26 dogs with lesions affecting the cauda equina and nerve roots between L6 and the first caudal vertebra, myelography was diagnostic in 21 dogs. Myelographic diagnosis of cauda equina compression was possible in seven dogs with spine in flexion. In 14 dogs, overextension of the spine and imaging in lateral and dorsal recumbency was necessary to establish a diagnosis. The five dogs with nondiagnostic myelograms had either a dural end-sac ending cranially to the lesion (two dogs), diseases not associated with compression (two dogs), or only slight indentations of the contrast medium column (one dog).     

Magnetic resonance imaging in the diagnosis and surgical management of sacral osteochondrosis in a mastiff dog

The clinical, radiographic, magnetic resonance imaging (MRI), surgical and pathological findings related to an osteochondral lesion of the sacrum in a mastiff dog are described. The dog showed chronic signs of pain in its pelvic limbs. Radiography revealed a triangular mineralised opacity at the craniodorsal aspect of the sacrum consistent with sacral osteochondrosis. A T2-weighted spin-echo MRI revealed dorsal and lateral compression of the cauda equina. The osteochondral fragment was removed via a dorsal laminectomy, and the clinical signs resolved. Histological abnormalities in the fragment were consistent with a diagnosis of osteochondrosis.