Schiff-Sherrington phenomenon in a cat with complete spinal cord transection from traumatic dorsocranial luxation of the second lumbar vertebra.

A young stray entire female domestic shorthair cat was presented with symmetrical forelimb extensor rigidity, neck hyperextension and hindlimb paraplegia, characteristic of Schiff-Sherrington phenomenon (SSP), within 30 min of a motor vehicle accident. Radiographic and post-mortem studies disclosed complete transection of the spinal cord from traumatic dorsocranial luxation of the second lumbar vertebra, displacement of the sacrum from the ilium, seventh lumbar and first caudal vertebrae and multiple pelvic fractures. Other causes of forelimb extensor rigidity and neck hyperextension such as decerebrate and decerebellate rigidity were excluded by a lack of neurological signs consistent with these entities and unremarkable findings on post-mortem examination of the cranial cavity and brain and histological examination of the cerebrum, brainstem and cerebellum. To the best of the author's knowledge, this is the first report of SSP in the cat outside the experimental arena of decerebrate or non-decerebrate preparations following post-brachial spinal cord transection/cold block.

Fentanyl-induced muscle rigidity in a dog during weaning from mechanical ventilation after emergency abdominal surgery: A case report.

A 22.5-kg, 8.4-year-old female mixed breed dog was presented for an emergency ovariohysterectomy for pyometra. No neurological abnormalities were observed on preoperative physical examination. Surgery was completed uneventfully under fentanyl- and sevoflurane-based anaesthesia. Cardiorespiratory indices remained stable under mechanical ventilation throughout the procedure. Approximately 23 min after the discontinuation of fentanyl infusion, the investigator noticed jaw closure and stiffness and thoraco-abdominal muscle rigidity. To rule out fentanyl-induced muscle rigidity, naloxone was administered. Following administration of naloxone, there was a return of spontaneous respiratory effort, indicated by capnogram and visible chest wall excursion. Based on the clinical signs and response to naloxone administration, the dog was diagnosed with suspected fentanyl-induced muscle rigidity. Six minutes after the return of spontaneous respiration, the dog was extubated uneventfully without additional naloxone administration. During 4 days of postoperative hospitalization, no recurrent muscle rigidity was observed, and the patient was discharged safely. The total dose of fentanyl administered was 0.61 mg (27 µg kg-1 ).

An evaluation of a target-controlled infusion of propofol or propofol-alfentanil admixture for sedation in dogs.

OBJECTIVES: To evaluate sedation quality and cardiorespiratory variables in dogs sedated using a target-controlled infusion of propofol or propofol-alfentanil admixture. METHODS: A total of 60 dogs undergoing diagnostic imaging were randomly assigned to one of three sedation protocols: propofol alone; propofol with a low concentration of 12 µg of alfentanil per mL of propofol; or propofol with a higher concentration of 24 µg of alfentanil per mL of propofol. Target-controlled infusion was initiated at a propofol target concentration of 1·5 µg/mL and increased until lateral recumbency was achieved. Times to adopt lateral recumbency and recover, pulse rate, respiratory rate, oscillometric mean arterial pressure and oxygen saturation were recorded. Quality of sedation onset and recovery were scored. RESULTS: Propofol target at lateral recumbency differed significantly (P=0·01) between groups with median (range) values of 3·0 (1·5 to 5·5), 2·0 (2 to 4·5) and 2·25 (1·5 to 3·5) µg/mL for propofol alone, propofol with the lower concentration of alfentanil and propofol with the higher concentration of alfentanil groups, respectively. Time to lateral recumbency was longer and quality of onset less smooth for the propofol group. Pulse rate change differed significantly (P<0·001) between groups (mean pulse rate change at onset of sedation: propofol group +2 ±24 bpm, low concentration alfentanil group -30 ±24 bpm, higher concentration alfentanil group -26 ±23 bpm). Hypoxaemia (SpO2 <90%) occurred in 1, 3 and 13 dogs, in the propofol group, the low concentration alfentanil group and the higher concentration of alfentanil group, respectively (P<0·001). CLINICAL SIGNIFICANCE: Addition of alfentanil to propofol target-controlled infusion did not confer cardiovascular benefits and, at the higher concentration, alfentanil increased the incidence of hypoxaemia.

A novel movement disorder in related male Labrador Retrievers characterized by extreme generalized muscular stiffness.

OBJECTIVES: To describe the clinical phenotype of a new motor disorder in Labrador Retrievers. ANIMALS AND METHODS: Case series study. Seven young male Labrador Retrievers presented for evaluation of stiff gait. RESULTS: All affected dogs had generalized muscular stiffness, persistent at rest and resulting in restricted joint movements. They showed a forward flexed posture, festinating gait, and bradykinesia. Signs developed between 2 and 16 months of age and tended to stabilize in adulthood. Needle electromyogram in the conscious state showed continuous motor unit activity in resting epaxial and proximal limb muscles. This activity was abolished by general anesthesia. Muscle and nerve histopathology was normal. In 2 dogs necropsied, astrocytosis was evident throughout the spinal cord gray matter, reticular formation and caudate nuclei. Decreased neuronal counts were selectively found in the spinal cord Rexed's lamina VII, but not in VIII and IX. Pedigree analysis showed that the affected dogs were from 5 related litters. CONCLUSIONS AND CLINICAL IMPORTANCE: This new hypertonicity syndrome in Labrador Retrievers is unique because of the selective distribution of the histological lesions, the lack of progression in adulthood, and its exclusive occurrence in male dogs. Pedigree analysis suggests an X-linked hereditary disease, although other modes of inheritance cannot be ruled out with certainty. We hypothesize that altered output from basal nuclei and reticular formation together with motor neuron disinhibition caused by a decreased number of spinal cord interneurons leads to the muscular stiffness.

Long-term follow-up of laminin alpha2 (merosin)-deficient muscular dystrophy in a cat.

Progressive muscle weakness beginning at 6 months of age was observed in a male Persian-mix cat. Muscle atrophy and joint contracture progressed over the next 3 years. The cat had developed gait difficulty at 8 months of age. The cat died at age of 5 years and 3 months due to an acute respiratory disorder. The clinical, laboratory, necropsy and histopathological findings of the cat were consistent with those of muscular dystrophy. The cat was diagnosed as having laminin alpha2 (merosin)-deficient muscular dystrophy on the basis of immunohistochemical findings. The cat was born in an inbred colony, and another related cat exhibited similar clinical signs. Few cases of laminin alpha2-deficient muscular dystrophy have been reported in cats, and this report provides additional information about the disease.

[Hypocalcemia in a four-week-old foal]. / Hypocalcemie bij een vier weken oud veulen.

Intake of Rumex, a plant genus of the Polygonaceae family, probably led through the assimilation of oxalic acid, to hypocalcaemia in a four-week old foal. This foal was presented with muscle rigidity and a stiff gait. Both the total and ionized calcium concentrations were low, 1.38 mmol/l and 0.54 mmol/l respectively. The foal was treated with a total of 150 ml of a 20% calcium solution IV. The foals neuromuscular signs resolved within a few hours after receiving calcium solution.

Haemodynamic, metabolic and physical responses to a neuroleptanalgesic-glyceryl guaiacolate combination in the horse.

A commercial neuroleptanalgesic acepromazine-etorphine combination administered intramuscularly to four horses produced a severe tachycardia and an increase in muscular tone, together with hypoxaemia, hypercapnia, metabolic acidosis associated with an increase in the packed cell volume and hyperglycaemia. No electrolyte changes were found. After reversal of the action of etorphine with diprenorphine, there was a prolonged decrease in the calcium and phosphorus serum concentrations and decreases in the packed cell volume and the total protein serum concentration. In a second experiment on the same four horses, glyceryl guaiacolate (10 g/100 kg body weight intravenously) was given as soon as the horses were anaesthetized with acepromazine-etorphine. The muscular rigidity disappeared and the tachycardia was less evident. There was a more pronounced hypoxaemia but the changes in the other parameters were similar to those in the first experiment. It was concluded that the neuroleptanalgesic-glyceryl guaiacolate combination is not a safe anaesthetic procedure in horses.

Neurologic manifestations of cerebrovascular atherosclerosis associated with primary hypothyroidism in a dog.

A 6-year-old, obese, spayed female Doberman pinscher dog was presented for clinical examination with a 1-day history of repeated seizures and a long-term history of periodic bouts of ataxia, circling, and head tilt. The seizures were controlled with phenobarbital, but the dog died 2 days after presentation. Necropsy revealed severe, diffuse, follicular atrophy of the thyroid gland (primary hypothyroidism), severe generalized atherosclerosis, severe pseudolaminar cortical necrosis and acute vasculitis in the cerebrum, and congestive heart failure. The neurologic signs were explained by the pseudolaminar necrosis and associated cerebrovascular atherosclerosis. The cerebrocortical necrosis was believed to be caused by tissue hypoxia secondary to progressive vascular occlusion. Cerebrovascular atherosclerosis, secondary to primary hypothyroidism, was considered the most important cause of the hypoxia.

Halothane testing for malignant hyperthermia in swine: dose-response effects.

Purebred Pietrain malignant hyperthermia (MH)-susceptible pigs (n = 102) were subjected to halothane (0%, 1%, 2%, 3%, 4%, and 5%) in oxygen. The number of pigs in each group exhibiting muscle rigidity (MH(+) reaction) and the reaction times were recorded, as were the number of deaths resulting from MH. Mortality was not affected by the halothane concentration. However, halothane concentration did markedly affect the number of MH(+) reactions and the reaction times. False-negative reactions were apparent in the pigs at halothane concentrations less than 3%. Increasing the halothane concentration incrementally to 5% (from 0%) significantly (P less than 0.05) decreased reaction times between treatment groups. The reductions in reaction times which occurred in the pigs given the 3%, 4%, and 5% halothane concentrations (62.1, 56.2, and 50.05)--although significant (P less than 0.05)--would indicate that 3% halothane would generally be sufficient for MH testing.

Porcine stress syndrome and postmortem muscle characteristics of two purebreds and three specific terminal crosses.

The incidence of Porcine Stress Syndrome (PSS), determined by halothane screening, and parameters of muscle quality and carcass leanness were studied in 108 pigs from a larger population of 658 pigs of Pietrain (P), Minnesota No. 1 (M), Hampshire (H) x (P x M), Yorkshire (Y) X (P X M) and P X (P X M) breeding. The larger population was also surveyed by the halothane screening procedure for incidence of PSS, and growth rate was measured. At 6 to 14 weeks of age, pigs were classified as PSS if they exhibited muscle rigidity within 5 min after the commencement of anesthetization with 3% halothane in oxygen. The incidences noted for the larger population were: H x (P x M) and Minnesota No. 1, 0%; Pietrain, 88%; Y x (P x M), 3%, and P x (P x M), 17%. Results demonstrated that the H x (P x M) group displayed excellent carcass meatiness combined with acceptable meat quality and freedom from PSS.

[Use of neuroleptic agents in modern pig-farming (author's transl)]. / Toepassing van neuroleptica in de moderne varkenshouderij

in pig-farming, the use of neuroleptic agents in conditions causing stress has increased. In the meaty type pig, this stress gives rise to specific symptoms such as acidosis, hyperthermia and muscle rigidity. This will result in death before or an abnormal meat quality (PSE-meat) after slaughter. The symptoms may also be produced in these pigs by having them inhale halothane (Fluothane), the symptoms being rapidly reversible. The inhibitory effect of various neuroleptic agents of the group of butyrophenone and phenothiazine derivatives on the appearance and course of the above symptoms is discussed. The extent to which the quality of the meat and mortality during transport is affected following administration of these agents to slaughter pigs as well as the degree to which hypersensitivity reactions to halothane are reduced in young pigs serve as models. Finally, public health and ethical aspects relating to the use of neuroleptic agents in farm animals are examined more closely.