Idiopathic polyneuropathy in Alaskan malamutes.

Clinical and morphologic features of a progressive polyneuropathy in young mature Alaskan Malamutes are described. Clinical signs included progressive paraparesis, synchronous pelvic limb gait, exercise intolerance, hyperesthesia, hyporeflexia, muscle atrophy, and tetraplegia. Electromyographic testing revealed diffuse fibrillation potentials and positive sharp waves in limb muscles, especially in muscles below the elbow and stifle. Pathologic findings in skeletal muscles and peripheral nerves included neurogenic muscle atrophy, focal or diffuse loss of myelinated nerve fibers, myelinoaxonal necrosis, and variable demyelination or remyelination. Ultrastructural changes included axonal degeneration, presence of numerous Büngner bands, and denervated Schwann cell subunits. The nature and distribution of abnormal electrophysiologic and pathologic findings were suggestive of a distal sensorimotor polyneuropathy, which we have termed idiopathic polyneuropathy of Alaskan Malamutes to distinguish this condition from hereditary polyneuropathy of Norwegian Alaskan Malamutes, last described in 1982.

Effect of intravenous administration of dextrose or lactated Ringer's solution on seizure development in dogs after cervical myelography with metrizamide.

The effect of fluid (5% dextrose in water or lactated Ringer's solution) administered intravenously on the development of seizures after cervical myelography with metrizamide was studied in 10 dogs. In a crossover experimental design, 8 dogs were used twice. Urine output was measured during the second part of the study to determine whether diuresis was a factor affecting seizure development. Dogs given 5% dextrose in water had significantly (P less than 0.05) fewer seizures than did dogs given lactated Ringer's solution. This was attributed to an increase in CSF glucose concentration and was not associated with diuresis.

Neuromuscular pedicle graft for restoration of arytenoid abductor function in dogs with experimentally induced laryngeal hemiplegia.

Left laryngeal hemiplegia was induced by resection of the left recurrent laryngeal nerve in 12 dogs. A neuromuscular pedicle graft formed from the first cervical nerve and sternothyroideus muscle was transplanted after 1 week to the denervated cricoarytenoideus dorsalis muscle in 8 dogs. The remaining 4 dogs served as controls. Left arytenoid abduction was blindly evaluated by laryngoscopy with video photography at time 0, at 1 week, and at 19 weeks in all dogs. At 19 weeks, biopsy specimens of the left cricoarytenoideus dorsalis muscle and the neuromuscular pedicle were taken from 4 of the treatment dogs, and biopsy specimens of the left cricoarytenoideus dorsalis muscle were taken from the 4 control dogs. All biopsy specimens were blindly evaluated by histologic and histochemical examination. At 36 to 44 weeks, the remaining 4 treatment dogs, from which biopsy specimens had not been taken, were reevaluated by use of laryngoscopy with video photography. Complications and difficulties encountered during surgery included hemorrhage in the area of the cricoarytenoideus dorsalis muscle, location of a branch of the first cervical nerve that was long enough to prevent tension at the graft site, orientation of the muscle pedicle in the cricoarytenoideus dorsalis muscle without the use of an operating microscope, and preservation of the terminal portion of the first cervical nerve while forming the neuromuscular pedicle. Results of the arytenoid movement evaluations revealed improvement in arytenoid abductor function in the treatment group, compared with that in the control group at 19 weeks. Arytenoid abduction in the treatment group at this time, however, was still significantly decreased (P less than 0.05), compared with presurgical movement evaluations.(ABSTRACT TRUNCATED AT 250 WORDS)

Use of pentobarbital sodium to reduce seizures in dogs after cervical myelography with metrizamide.

We conducted a prospective study to examine the effect of pentobarbital administration on the development of seizures in dogs that had undergone cervical myelography with metrizamide while anesthetized with halothane. Thirty dogs scheduled for cervical myelography were assigned to 3 groups. Dogs in group 1 received no pentobarbital. Those in group 2 were administered pentobarbital (5 mg/kg, IM) before induction of anesthesia, and those in group 3 received pentobarbital at the end of the procedure when the anesthetic vaporizer was turned off. Anesthesia was induced with thiamylal sodium in all dogs and was maintained with halothane. Dogs that underwent surgery immediately after the myelography were not included in the study. A significant difference was not found among the 3 groups in terms of number of dogs that had seizures, mean body weight of the dogs, duration of anesthesia after injection of metrizamide, time from extubation to first seizure, volume of metrizamide injected, or clinician performing the myelography.

Neuroaxonal dystrophy in a rottweiler pup.

An 8-month-old Rottweiler pup was evaluated for neurologic disorder. Clinical signs included ataxia, hypermetria of all 4 limbs, intention tremors of the head, lack of a menace reflex bilaterally, and mild proprioceptive deficits. The pup was euthanatized because of the progressive nature of the disease. Histopathologic findings consisted of decreased numbers of Purkinje cells in the cerebellum and moderate numbers of axonal spheroids in the nucleus cuneatus. This latter finding confirmed the diagnosis of neuroaxonal dystrophy.

Selected contrast studies. Portal venography and cerebral angiography.

Portography is the most commonly used technique for demonstrating portal venous anatomy and abnormal communications between the portal and systemic venous systems. This article reviews normal anatomy, anomalies, and radiology of the portal venous system. Also included is a discussion of cerebral angiography, which is mainly used in the diagnosis of space-occupying lesions of the brain.

Comparison of cerebrospinal fluid pressure in propofol- and thiopental-anesthetized eucapnic dogs.

Cerebrospinal fluid pressure (CSFp) was measured as part of the neurologic assessment of dogs with suspected intracranial disease. Because propofol has not been shown to cause an increase in intracranial pressure in humans, the authors examined its effect on (CSFp) in dogs to determine if it would be an appropriate substitute for thiopental as an anesthetic agent for the measurement of CSFp. The CSF pressure in eucapnic propofol-anesthetized dogs (105 +/- 5.6 mm H2O) was not significantly different (p < .05) from CSFp in eucapnic thiopental-anesthetized dogs (103.8 +/- 6.6 mm H2O).

Extradural spinal angiolipoma associated with bone lysis in a dog.

An extradural spinal tumor was diagnosed in a 12-year-old Labrador retriever that was presented with a one-week history of paraparesis. Myelography indicated a deviation of the spinal cord to the right side at the level of the second lumbar (L2) vertebra. The difference in length measuring the left and right sides of the L2 vertebra suggested a fracture of the vertebral body. Severe bone remodeling and an extradural mass were seen on computed tomography (CT). Clinical, radiographical, and histological findings are described and considered homologous to extradural angiolipomas described in the human literature.

Perineurial abnormalities in the spontaneously diabetic dog.

Structural abnormalities of the perineurium from six spontaneously diabetic dogs (diabetes duration 4-8 years and six control animals were quantified using detailed electron microscopic morphometric methods on superficial peroneal nerve biopsy specimens. Total perineurial sheath thickness (microm) was significantly increased in diabetic (8.8+/-0.6) compared to control animals (6.2+/-0.3) (P < 0.02). This was attributed to a significant increase in the mean perineurial lamellar width in diabetic (0.49+/-0.03) compared to control (0.40+/-0.01) (P < 0.04) animals. The number of lamellae also showed a non-significant increase in diabetic animals (7.8+/-0.4) compared to controls (6.9+/-0.13) (P < 0.06). There was no change in the mean interlamellar space in diabetic (0.7+/-0.05) compared to control (0.6+/-0.06) (P = 0.15) animals. The total interlamellar space was increased in diabetic (5.7+/-0.5) compared to control (4.1+/-0.36) (P < 0.04) animals. The perineurial cell basement membrane thickness (nm) was significantly increased in diabetic (126.9+/-9.8) compared to control (62.8+/-6.1) (P < 0.005) animals. The current study has demonstrated significant abnormalities of the perineurium in the spontaneously diabetic dog, which may have relevance to the pathogenesis of diabetic neuropathy.