Treatment of sacro-coccygeal intervertebral disc extrusion causing tail paresis and faecal incontinence in a dog

A 4-year 9-month-old beagle was presented for a 2-week history of acute onset of lowered tail carriage and faecal incontinence. Neurological examination was unremarkable except for an absent perineal reflex, there was no history of trauma. Blood work was unremarkable. Lumbosacral and coccygeal CT pre- and post-intravenous contrast revealed a large sacrococcygeal disc extrusion with mineralised material extending from the level of S2 and to midbody of Cd1. A dorsal laminectomy was performed from the cranial margin of S2 to the caudal margin of Cd1. A large volume of mineralised disc material was removed. The material was confirmed on histopathology to be consistent with extruded nucleus pulposus. The patient regained faecal continence within 3 days of hospital discharge. Based on a literature search this is the first report of a sacrococcygeal disc extrusion resulting in faecal incontinence, with successful surgical management.     

Acute intervertebral disc extrusion in a cat: clinical and MRI findings

A 5 year old, neutered male, domestic shorthaired cat had acute left hemiparesis and Horner's syndrome. Magnetic resonance imaging (MRI) revealed a loss of the normal signal from the nucleus pulposus of the intervertebral disc at C3/4, narrowing of the ventral subarachnoid space and slight dorsal displacement of the spinal cord and a focal hyperintense lesion affecting the left side of the spinal cord at the same level. The presumptive diagnosis was focal spinal cord oedema associated with intervertebral disc extrusion. A traumatic aetiology was suspected. The cat was treated conservatively and improved gradually over a period of 6 months.     

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.     

Contrast-enhanced CT for localizing compressive thoracolumbar intervertebral disc extrusion

Thoracolumbar intervertebral disc extrusion is a common disease in dogs. Surgical decompression of the spinal cord is the preferred treatment. Localization of the compressive material is critical for surgical planning. Myelography has been used for localizing extruded disc material, but this procedure carries risk of complications. Computed tomography (CT) is becoming more available for use in veterinary medicine and CT myelography is used for localization of extruded disc material. This report compares CT with intravenous contrast medium and CT myelography for identifying extruded intervertebral discs. CT with intravenous contrast medium is as effective as CT myelography for determining level and laterality of compressive disc extrusions.     

Fecal incontinence associated with epidural spinal hematoma and intervertebral disk extrusion in a dog

CASE DESCRIPTION: A 7-year-old castrated male Great Dane was evaluated because of a 2-month history of fecal incontinence. CLINICAL FINDINGS: On the basis of the presence of paraparesis and apparently normal spinal reflexes, the neurologic signs were localized in the region of the third thoracic to the third lumbar spinal cord segments. On the basis of the findings of magnetic resonance imaging, a presumptive diagnosis of a compressive intervertebral disk extrusion with secondary hemorrhage and epidural hematoma formation was made. TREATMENT AND OUTCOME: A right-sided hemil-aminectomy was performed (centered at the T13-L1 intervertebral space) to further characterize the lesion and decompress the spinal cord. The histopathologic diagnosis was extruded intervertebral disk material with chronic hemorrhage and inflammation. Three weeks after surgery, there was complete resolution of the dog's fecal incontinence and moderate improvements in its hind limb function. CLINICAL RELEVANCE: Thoracolumbar spinal cord injuries can result in upper motor neuron fecal incontinence in ambulatory dogs. Epidural spinal hematomas may develop secondary to intervertebral disk herniations and cause spinal cord compression resulting in neurologic deficits.     

Immunohistochemical demonstration of lumbar intervertebral disc innervation in the dog

Low back pain is a common ailment in dogs, particularly in specific breeds such as the German shepherd dog. A number of structures such as facet joint capsules, ligaments, dorsal root ganglia, periosteum, vertebral endplates and meninges have been associated with this condition. Yet, in spite of all diagnostic efforts, the origin of pain remains obscure in a substantial proportion of all cases. A further structure often being involved in vertebral column disorders is the intervertebral disc. The presence of nerves, however, is a precondition for pain sensation and, consequently, structures lacking innervation can be left out of consideration as a cause for low back pain. Nerve fibres have been demonstrated at the periphery of the intervertebral disc in man, rabbit and rat. With regard to the dog, however, the extent of intervertebral disc innervation is still being disputed. The goal of the present study, therefore, was to substantiate and expand current knowledge of intervertebral disc innervation. Protein gene product (PGP) 9.5 was used for immunohistochemical examination of serial transversal and sagittal paraffin sections of lumbar discs from adult dogs. This general marker revealed nerve fibres to be confined to the periphery of the intervertebral discs. These results indicate that even limited pathological processes affecting the outer layers of the intervertebral disc are prone to cause low back pain.     

Intervertebral disc degeneration in the dog. Part 1: Anatomy and physiology of the intervertebral disc and characteristics of intervertebral disc degeneration

Intervertebral disc (IVD) degeneration is common in dogs and can give rise to a number of diseases, such as IVD herniation, cervical spondylomyelopathy, and degenerative lumbosacral stenosis. Although there have been many reports and reviews on the clinical aspects of canine IVD disease, few reports have discussed and reviewed the process of IVD degeneration. In this first part of a two-part review, the anatomy, physiology, histopathology, and biochemical and biomechanical characteristics of the healthy and degenerated IVD are described. In Part 2, the aspects of IVD degeneration in chondrodystrophic and non-chondrodystrophic dog breeds are discussed in depth.     

Presence of residual material following mini-hemilaminectomy in dogs with thoracolumbar intervertebral disc extrusion

Presence of residual material following mini-hemilaminectomy in dogs (n = 9) with spontaneous thoracolumbar intervertebral disc extrusion was prospectively investigated. Volume of extruded disc material within the vertebral canal and the proportion of residual material were determined using pre- and post-operative magnetic resonance imaging. The degree of spinal cord compression, proportion of extradural material considered hemorrhage, and invasion of the articular facets were also determined. Residual material was identified in 44% of the mini-hemilaminectomies. The median percentage of residual material calculated was 7.7% of the preoperative volume. No observed effect of surgical side or site, proportion of extradural material considered hemorrhage, patient weight, and duration of clinical signs was detected.     

Comparison of hemilaminectomy and dorsal laminectomy for thoracolumbar intervertebral disc extrusion in dachshunds

Neurological improvement after decompressive surgery, without routine therapeutic or prophylactic disc fenestration, was evaluated retrospectively in a consecutive series of 93 dachshunds with thoracolumbar disc extrusion. In 24 per cent of procedures, deep pain sensation was not elicited in at least one hind paw before surgery. Median neurological status one to seven days after surgery, at the time of discharge, was significantly improved after hemilaminectomy compared with dorsal laminectomy (P < 0·05). After hemilaminectomy, deep pain sensation was not elicited in one or both hind paws of 8 per cent of dogs in which pain sensation was elicited before surgery, compared with 21 per cent after dorsal laminectomy (P > 0·05). Improvement in neurological grade at follow-up examination two to 12 weeks after hemilaminectomy was not significantly different compared with dorsal laminectomy (P > 0·05). Of dogs which were unable to walk before surgery, 83 per cent regained the ability to walk after hemilaminectomy, compared with 74 per cent after dorsal laminectomy (P > 0·05). In both groups, 50 per cent of dogs in which deep pain sensation was abnormal before surgery eventually regained the ability to walk after surgery (P = 1). One to two years after the first operation, a second laminectomy was performed in only 5 per cent of dogs because of extrusion of a different intervertebral disc which had not been fenestrated.     

Early recurrence of thoracolumbar intervertebral disc extrusion after surgical decompression: a report of three cases

Thoracolumbar disc extrusions were diagnosed in three chondrodystrophic dogs with paraparesis of up to three days duration. All cases were managed by hemilaminectomy and removal of extruded disc material. In one dog, fenestration of the herniated disc space was also performed. Initially neurological function improved or was unchanged, but from two to ten days postoperatively clinical signs of deterioration became apparent. In all the dogs, recurrence of disc extrusion at the same location as the initial extrusion was diagnosed by computer tomography and at a second surgery abundant disc material was found at the hemilaminectomy site between the dura and an implanted graft of autogenous fat.     

Disc extrusion in a Rottweiler dog with caudal cervical spondylomyelopathy after failure of intervertebral distraction/stabilisation

A Rottweiler dog was presented with an 8 week history of hindlimb ataxia. Neurological examination localised the lesion to the cervical spinal cord. Myelography demonstrated dynamic compressive lesions at C5-6 and C6-7 consistent with a diagnosis of caudal cervical spondylomyelopathy. Distraction/stabilisation of both discs was performed using interbody polymethyl methacrylate. Both implants subsequently failed leading to extrusion of the remaining dorsal annulus fibrosus of the C5-6 intervertebral disc and nonambulatory tetraparesis. A ventral slot combined with distraction/stabilisation using screws and polymethyl methacrylate was performed and resulted in nearly full neurological recovery.     

Surgical management of first caudal nerve root foraminal compression secondary to intervertebral disc disease in a Cocker Spaniel

A nine-year-old spayed female Cocker Spaniel was investigated for an eight week history of licking and rubbing at the tail base, dullness, and signs of pain on manipulation of the tail. Left-sided intraforaminal compression of the first caudal nerve root due to intervertebral disc disease was diagnosed by radiographic, computed tomography, and magnetic resonance imaging examinations. The dog was nonresponsive to conservative medical therapy. A decompressive left-sided first-second caudal (Cd1-Cd2) foraminotomy was performed. Postoperative computed tomography confirmed surgical decompression of the involved nerve root. At the one month follow-up examination there was marked improvement in clinical signs. At two months, clinical signs were completely resolved and there was not any evidence of recurrence twelve months after surgery. Intervertebral disc disease should be considered as a differential diagnosis in dogs with discomfort at the tail base or signs of pain on manipulation of the tail. Surgical decompression may be indicated for management of these cases. This is the first report of diagnosis and surgical management of caudal intervertebral disc disease by foraminotomy in the dog. Surgical decompression by foraminotomy may therefore be a treatment option for this condition.