A case report of traumatic neuroma of the cervical spinal cord in a dog

Traumatic neuroma of the cervical spinal cord was diagnosed in a 14-year-old male mixed-breed dog. A gross view showed two intradural extramedullary masses, measuring 1 and 0.6 cm in length and 0.7 and 0.4 cm in diameter, attached to the left side of the spinal cord at the level of the sixth and seventh cervical vertebrae. Microscopically, the cervical spinal masses comprised interlacing fascicles of axons and Schwann cells surrounded by collagenous stroma. Immunohistochemically, the fascicles were stained positively for neurofilament and S-100 proteins. Ultrastructurally, variably sized myelinated fibers and onion bulb-like structures were observed. To our knowledge, this is the first report of a traumatic neuroma in the cervical spinal cord of a dog.     

Spinal mast cell tumor in a dog.

A 6-year-old, spayed female rottweiler was referred for left forelimb lameness followed by tetraparesis. A mast cell tumor compressing the spinal cord at the level of the sixth cervical to first thoracic (C6-T1) vertebrae was diagnosed based on cervical myelography and necropsy findings. This was considered a primary extracutaneous mast cell tumor, as no evidence of disease was found elsewhere. This is the first report of a primary mast cell tumor in this location.     

Compressive myelopathy associated with ectasia of the vertebral and spinal arteries in a dog

A 4-year-old dog was presented for acute, progressive tetraparesis and cervical hyperesthesia. Symmetrical tubular structures coursing along the lateroventral aspects of the spinal cord at the fourth and fifth cervical vertebrae were identified in magnetic resonance images. At necropsy, vertebral arteries and their spinal branches were severely ectatic bilaterally, and the cervical spinal cord was compressed. Histologically, the ectatic branches of the vertebral and ventral spinal arteries were surrounded by fibrosis with scant mononuclear cell infiltrates and hemorrhage. Spinal branches of the vertebral arteries had focally severe reduction in the tunica media. A thrombus was in an arterial branch. Smaller vessels in adjacent tissue had fibrinoid degeneration. Axonal degeneration was detected in the affected spinal cord and nerve roots. The segmental degenerative radiculomyelopathy in this dog was attributed to anomalous ectasia of the vertebral and ventral spinal arteries.     

Subarachnoid abscess as a complication of discospondylitis in a dog

A three-year-old German shepherd dog was presented with a history of acute neck pain. A diagnosis of acute discospondylitis involving two intervertebral disc spaces was made. The dog initially responded to conservative treatment over an eight-week period and then suddenly deteriorated. Spinal cord compression was evident on cervical myelography. At autopsy, a subarachnoid abscess was present at the intervertebral disc space between the sixth and seventh cervical vertebrae.     

Tetraparesis in a cat with fibrocartilaginous emboli

An 8-year-old cat, with a history of ataxia that progressed to tetraparesis over a 5-day period, was evaluated. A lesion was localized to the sixth cervical (C6) to second thoracic (T2) spinal cord segments based on physical and neurological examination findings. Blood work was unremarkable, as was survey radiography of the thoracic and abdominal cavities. Cerebrospinal fluid analysis showed moderate neutrophilic inflammation. A definitive diagnosis was not made until necropsy, at which time intravascular fibrocartilaginous embolization (FCE) of the cervical spinal cord was identified. This is only the third published report of FCE in the feline species and the first such case involving the cervical spinal cord.     

Investigations on the Postnatal Development of the Macroscopic Proportions and the Topographic Anatomy of the Feline Spinal Cord

The aim of this work was to investigate the postnatal development of the feline spinal cord. Our study showed that the main period of growth leading to the cervical and lumbar enlargements begins after birth and is completed at the age of 5–6 months. Comparing the relationship between the length of the spinal cord and the vertebral column, we found that in contrast to the adult cat, in the newborn cat, length, area and volume of segments show similar values along the spinal cord. This also applied to the length of the vertebrae. Due to a heterogeneous growth, not all segments of the spinal cord end up situated cranial to their corresponding vertebrae. As a consequence, the end of the conus medullaris is still located within the sacral canal in animals older than 2 months. These findings strongly propose that injections into the vertebral canal of the cat have to be performed caudal to the sacral vertebrae.     

Cervical stenotic myelopathy in a horse

A 13-year-old, Thoroughbred gelding presented with a 3-year history of progressive ataxia of all 4 limbs. Physical and neurological examinations indicated a compressive lesion affecting the cervical spinal cord. Radiographs confirmed a lesion, and a myelogram a narrowing of the spinal canal at cervical vertebrae (6-7). Necropsy confirmed cervical stenotic myelopathy.     

Osteochondrotic changes in the vertebrae of four ataxic horses suffering from cervical vertebral malformation

Ataxia caused by a focal compression of the cervical spinal cord was diagnosed in four young standardbred trotting horses. Diagnosis was verified by myelography. Changes in the cervical vertebral column were studied using microradiographic and histologic methods. In the vertebrae involved, there was irregularity of the cartilaginous growth zone, cracks with a loose fragment and disturbance in the enchondral ossification. These changes resemble osteochondrosis. Porous appearance in lateral and ventral funiculi as well as mural calcified plaques in the small vessels of the white matter were found in the spinal cord.     

Dynamic Compression of the Cervical Spinal Cord: A Myelographic and Pathologic Investigation in Great Dane Dogs

The authors report the radiographic and pathologic findings in 10 Great Dane dogs with the wobbler syndrome. In all 10 dogs it was possible to demonstrate myelographically that there was cervical spinal cord compression at 1 or 2 sites. The spinal cord compression was mainly dynamic in nature, as degree of compression increased in extension and decreased in flexion of the neck in 8 dogs. In 1 dog with deformed vertebral bodies (G6 and C7), compression increased slightly in flexion of the neck. In another dog, compression was lateral and could only be seen in the ventrodorsal view.The macroscopic findings substantiated the radiologic findings. The cause of the spinal cord compression was in 8 dogs a decrease in the dorsoventral diameter of the orifice of the vertebral canal of 1 or 2 vertebrae in combination with deformation and elongation of 1 or several vertebral arches. In extension of the neck, the cervical spinal cord was squeezed between the anterior tip of the elongated vertebral arch and the caudodorsal rim of the body of the adjacent cranial vertebra.Histologic examination was made of the spinal cord in 5 dogs and the compressive lesions that were found could explain the neurologic signs.In the discussion, the question is raised as to why pain is not a prominent sign in dogs with the wobbler syndrome in contrast to in dogs with cervical disc protrusion. It is believed that the inflammatory foreign body reaction, triggered by the protruded calcified nucleus pulposus is the main cause of pain in the disc protrusion syndrome. In the wobbler syndrome there is no obvious inflammatory reaction in the epidural space.Finally, the possible etiologic factors oC importance for the deformation oC the cervical vertebrae in wobblers are discussed. There are indications that both overnutrition and a genetic trait for rapid growth are of importance.     

CERVICAL VERTEBRAL FUSION AND CONCURRENT INTERVERTEBRAL DISC EXTRUSION IN FOUR DOGS

Cervical vertebral fusion was noted radiographically in four dogs presented for signs of cervical spinal cord compression. Ventral extradural spinal cord compression was seen on myelography at intervertebral disc spaces adjacent to the fused vertebrae in two dogs and at a site removed in two dogs. At surgery, no intervertebral disc space was found in the area of fusion. No other instances of cervical vertebral fusion were identified in reviewing radiographs of 1225 other dogs with cervical intervertebral disc extrusion evaluated at our hospital. Clinical signs resolved in all dogs after surgical removal of extruded intervertebral disc material. Information from these four dogs suggest vertebral fusion may predispose adjacent discs to herniation.     

Suspected cervical spinal cord vascular anomaly in an African warthog (Phacochoerus africanus).

Vascular myelopathies of the spinal cord have not been described in Suidae, and are a rare finding in companion animals. An 8.5-yr female African warthog (Phacochoerus africanus) presented with an acute onset of tetraparesis. Based on neurologic findings, a cervical spinal cord lesion between C7-T2 was suspected. Magnetic resonance imaging revealed severe intramedullary hemorrhage with suspected abnormal vessels in the spinal cord at the level of the seventh cervical vertebrae. The acute onset of clinical signs and rapid deterioration of neurological status precluded surgical managements. A vascular anomaly was suspected on gross pathology and histology. Immunohistochemistry identified the lesion as a spontaneous intramedullary hematoma. Spontaneous intramedullary hematomyelia should be considered as a differential for acute onset of paresis in suid species.     

An ectopic wing in a wild black vulture (Coragyps atratus)

An approximately 5-month-old black vulture (Coragyps atratus) was presented with the chief complaint of cervicomelia. A full-sized ectopic wing, with its own pectoral girdle, was found attached to the dorsal surface of the last few cervical vertebrae. There was deformation (right dorsolateral narrowing) of the spinal canal at the point of attachment with a corresponding compression of the spinal cord.     

Sacrocaudal agenesis in a Korean native calf (Bos Taurus Coreanae)

A male deformed Korean native calf was examined macroscopically. The deformed calf had no caudal vertebral columns from 5th lumbar vertebra, sacrum and coccygeal vertebrae. The spinal cord was terminated in the vertebral foramen of the 3rd lumbar vertebra. The cervical vertebrae had scoliosis and the 3rd and 4th cervical vertebrae were fused. The 2nd and 3rd lumbar vertebrae were fused and the left and right transverse processes of the 4th lumbar vertebra articulated with ala of the ilium. The rectum was greatly expanded by the imperforate anus and a rectourethral fistula was formed between the rectum and urethra. The deformed calf was recorded as a first documentation of sacrocaudal agenesis confirmed in a Korean native calf.     

Study on the Developmental Changes in Angulation of Spinal Nerves, the Length of the Dorsal Roots and Spinal Nerves in Sheep

This study reports the angulation of spinal nerves, the length of dorsal roots, the length of spinal nerves and the transverse and vertical diameters of the spinal cord during pre- and postnatal life in sheep of the Mehraban breed in Iran. The spinal cord of these animals was divided into 4 regions with respect to the angulation of spinal nerves. The first region was from the first to fifth cervical and the second was from the sixth cervical to the eighth thoracic in fetuses and from the six cervical to fourth thoracic in adults. The third region was from the ninth thoracic to second lumbar in fetuses and from the fifth thoracic to second lumbar in adults, and the fourth region was from third lumbar to fourth sacral in the animals of all age groups. The length of dorsal roots from their point of emergence from the spinal cord to the dorsal root ganglia showed a direct correlation with the length of the spinal nerves. While angulation of the spinal nerves showed a converse correlation with the length of either spinal nerves or dorsal roots. The transverse diameters of the spinal cord were always longer than the vertical diameters. The greatest diameters (vertical — 7.00 mm; transverse — 10.00 mm) are recorded at C1, T1 and L6 in adult sheep.     

Large interarcuate spaces in the cervical vertebral column of the tyrolean mountain sheep

Large interarcual spaces have been described between the arcus vertebrae C5/C6 and C6/C7 in the cervical vertebral column of Nubian goats. This aperture enables direct access to spinal cord and rootlets without the need to perform a hemilaminectomy. The present study was performed in order to determine whether these large interarcual spaces can also be found in the vertebral column of the Tyrolean mountain sheep, as this small ruminant, which is anatomically very similar to the Nubian goat, is frequently used for experimental purposes at the Surgical University Clinic in Austria. The carcasses of 10 sheep (six females, four males; range of age: 2.5-6 years, range of weight: 52-89 kg) were dissected and the vertebral column was exposed. All 10 sheep showed elliptic openings between the fourth cervical and the first thoracal vertebrae. Three sheep had additional openings between the first and the second thoracal vertebrae. All openings were covered solitarily by the ligamentum flavum and under this ligamentum lay the spinal cord without any further osseous or ligamentous protection. These findings are not mentioned in the common textbooks of veterinary anatomy and deserve attention, as they can be a step forward towards non-traumatic experimental surgery on the spinal cord.     

Postanesthetic hemorrhagic myelopathy in a horse

Acute hemorrhagic myelopathy developed in the sixth cervical to the eighth thoracic spinal cord segments of a 1-year-old Quarter Horse colt that was castrated under general anesthesia while in dorsal recumbency. Clinical signs were consistent with severe transverse myelopathy caudal to the brachial enlargement and cranial to the lumbosacral enlargement of the spinal cord. Histologic examination of the spinal cord revealed hemorrhage in the gray matter, with multiple blood-filled clefts in otherwise normal neuropil. Hemodynamic changes in the spinal cord associated with anesthesia and dorsal recumbency may have led to hypoxic vessel damage, with massive hemorrhage after surgery, when the horse was returned to lateral recumbency. Postanesthetic hemorrhagic myelopathy is a possible complication of positioning in dorsal recumbency, during anesthesia, in rapidly growing, young horses.     

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.     

Pneumorrhachis in a rottweiler

An 8·5-year-old, female, neutered, Rottweiler was presented for investigation of progressive ataxia of one week duration. Proprioception was absent in the left pelvic limb and reduced on the right, thoracolumbar hyperalgesia was evident and pelvic limb segmental spinal reflexes were normal. Magnetic resonance imaging (MRI) demonstrated a spherical region of signal void compressing the spinal cord between the fifth and sixth thoracic vertebrae and several non-compressive degenerate intervertebral discs. Computed tomography (CT) of the region confirmed the findings and identified the lesion as gas. A dorsolateral hemilaminectomy was performed to decompress the spinal cord and achieved complete resolution of the clinical signs on examination after 3 months. This is the first known reported case of spontaneous pneumorrhachis in a veterinary patient.     

Cervical chondroid chordoma in a standard dachshund: a case report

A ten-year-old male standard dachshund was presented with a history of neck pain and progressive gait disturbances. Following a neurological examination and diagnostic imaging, including CT, a neoplastic lesion involving the third and fourth cervical vertebrae was suspected. The lesion included an extradural mass on the right side of the spinal canal causing a local compression of the cervical cord. Surgery, using a modified dorsal laminectomy procedure, was performed in order to decompress the cervical spinal cord. Histopathological examination of the extradural mass indicated that the tumour was a chondroid chordoma. Following discharge, the quality of life for the dog was very good for a sustained period, but clinical signs recurred at 22 months. The dog was euthanased 25 months post-surgery. On post-mortem examination, a regrowth of neoplastic tissue was found to have infiltrated the bone and spinal cord at C3-C4. This is the first report to show that palliative surgery can offer successful long-lasting treatment of chondroid chordoma of the cervical spine in the dog.     

Malignant peripheral nerve sheath tumor with divergent mesenchymal differentiations in a dog.

A malignant peripheral nerve sheath tumor with divergent osteogenic, myxomatous, and myoblastic differentiations is described in a 10.5-year-old male Labrador Retriever dog. The tumor involved the sixth and seventh cervical spinal cord segments and nerves. The diagnosis was based on the results of histopathology, electron microscopy, and immunohistochemistry.