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An 11-year-old 32-kg (70.4-lb) spayed female Labrador Retriever was evaluated at the University of Georgia College of Veterinary Medicine because of exophthalmos and epiphora of the right eye. Additionally, the owners perceived that the right eye was painful because the dog would squint that eye when the area of the head near the eye was touched. Physical examination findings were considered normal with the exception of exophthalmos, decreased retropulsion, and slight protrusion of the third eyelid of the right eye. Signs of pain were elicited when transpalpebral pressure was applied to the right eye. Examination of the left eye revealed

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in Journal of the American Veterinary Medical Association
History

A 7-year-old 8.1-kg (17.8-lb) spayed female Cocker Spaniel–Poodle mix was evaluated because of lethargy, behavioral changes, and signs of pain that were difficult to localize. Four months prior, the dog started to have signs of pain and displayed aggressive behavior. One month later, the dog fell and subsequently developed intermittent ataxia of the pelvic limbs and a reluctance to bear weight on the right pelvic limb. The dog was treated for suspected intervertebral disk herniation, but its condition did not improve, and a referral examination was arranged. Additional history included enucleation of the right eye owing to a ruptured

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To establish reference values for electrodiagnostic evaluation of peripheral nerve function in birds.

Animals—6 rheas and 6 barred owls.

Procedure—Birds were anesthetized with propofol or isoflurane in oxygen. Using a computer-based electromyograph system and needle electrodes for stimulation and recording, electromyography (EMG) was performed on the pectoral, biceps brachialis, and gastrocnemius muscles, and evoked EMG was performed on the tibial and ulnar nerves. Motor nerve conduction velocity (MNCV) was calculated. Repetitive stimulation was performed on these 2 nerves. Late F waves were recorded for each nerve, when possible.

Results—Activity was evident during insertion of the electrodes, but muscles tested were electrically quiescent after spontaneous EMG. Motor nerve conduction velocity was faster in the tibial nerve than ulnar nerve but did not differ significantly between species. Mean ± SEM MNCV was 132.3 ±± 7.8 m/s for the tibial nerve and 59.7 ± 7.8 m/s for the ulnar nerve. A significant difference was not observed in responses at the fourth or ninth stimulation during repetitive stimulation. Subsequent to the initial stimulation, amplitudes were ± 22.7% of the initial motor potential amplitude. Recorded F waves were inconsistent, which may have been associated with technique.

Conclusions and Clinical Relevance—Reference range (mean ± 2 SEM) for MNCV was 34.1 to 75.3 m/s for the ulnar nerve and 116.7 to 147.9 m/s for the tibial nerve in barred owls and rheas. After repetitive stimulation, motor potential amplitudes may be ± 22.7% of the initial amplitude response. (Am J Vet Res 2000;61:469–472)

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in American Journal of Veterinary Research

A 9-year-old 42-kg (92.4-lb) neutered male Golden Retriever was referred to the University of Georgia because of chronic, progressive ambulatory paraparesis of 3 weeks’ duration. At the onset, the dog appeared to be in pain and had difficulty standing up on the pelvic limbs. The referring veterinarian treated the dog with meloxicam (0.8 mg/kg [0.36 mg/lb], PO, q 12 h). One week later, the dog began scuffing the dorsum of the foot of the right pelvic limb. Administration of meloxicam was discontinued, and the dog was treated with prednisone (1.0 mg/kg [0.45 mg/lb], PO, q 12 h), with the

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in Journal of the American Veterinary Medical Association
Problem

A 12-year-old spayed female mixed-breed dog was brought to the University of Georgia Veterinary Teaching Hospital for evaluation because of 2 clusters of generalized seizures. Four months previously, the dog had had 5 generalized seizures in a single day. One week before the evaluation, the dog had had a second episode of cluster seizures (6 generalized seizures in a 24 hour-period).

At the time of hospital admission, a physical examination and neurologic examination were performed, and results were unremarkable. The neurologic disturbance was localized to the prosencephalic region on the basis of the dog's history of seizure activity. A

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in Journal of the American Veterinary Medical Association

Abstract

OBJECTIVE To determine the physiochemical properties and pharmacokinetics of 3 midazolam gel formulations following buccal administration to dogs.

ANIMALS 5 healthy adult hounds.

PROCEDURES In phase 1 of a 2-phase study, 2 gel formulations were developed that contained 1% midazolam in a poloxamer 407 (P1) or hydroxypropyl methylcellulose (H1) base and underwent rheological and in vitro release analyses. Each formulation was buccally administered to 5 dogs such that 0.3 mg of midazolam/kg was delivered. Each dog also received midazolam hydrochloride (0.3 mg/kg, IV). There was a 3-day interval between treatments. Blood samples were collected immediately before and at predetermined times for 8 hours after drug administration for determination of plasma midazolam concentration and pharmacokinetic analysis. During phase 2, a gel containing 2% midazolam in a hydroxypropyl methylcellulose base (H2) was developed on the basis of phase 1 results. That gel was buccally administered such that midazolam doses of 0.3 and 0.6 mg/kg were delivered. Each dog also received midazolam (0.3 mg/kg, IV). All posttreatment procedures were the same as those for phase 1.

RESULTS The H1 and H2 formulations had lower viscosity, greater bioavailability, and peak plasma midazolam concentrations that were approximately 2-fold as high, compared with those for the P1 formulation. The mean peak plasma midazolam concentration for the H2 formulation was 187.0 and 106.3 ng/mL when the midazolam dose administered was 0.6 and 0.3 mg/kg, respectively.

CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that buccal administration of gel formulations might be a viable alternative for midazolam administration to dogs.

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in American Journal of Veterinary Research

Abstract

Objective—To measure concentrations of glutamate, aspartate, γ-aminobutyric acid (GABA), and glycine in CSF of dogs with experimentally induced subarachnoid hemorrhage (SAH) and to assess effects of cyclosporine and simvastatin on these concentrations.

Sample—CSF samples from 13 dogs.

Procedures—In a previous study, SAH was induced in dogs via 2 injections of autologous blood into the cerebellomedullary cistern 24 hours apart. Dogs were untreated (control; n = 5) or received simvastatin alone (4) or simvastatin in combination with cyclosporine (4). Samples of CSF were collected before the first blood injection (baseline; time 0), before the second blood injection, and on days 3, 7, and 10. For the study reported here, neurotransmitter concentrations in CSF were analyzed via high-performance liquid chromatography. Data were analyzed with a repeated-measures model with adjustments for multiple comparisons by use of the Tukey method.

Results—In control dogs, the glutamate concentration peaked on day 3 and there was a significant increase in GABA and glutamate concentrations. Glutamate concentrations were significantly lower and glycine concentrations significantly higher on day 3 after administration of simvastatin alone or simvastatin in combination with cyclosporine, compared with concentrations for the control group. No significant differences in GABA and aspartate concentrations were detected among treatment groups at any time point.

Conclusions and Clinical Relevance—Glutamate concentrations were increased in the CSF of dogs with SAH. Simvastatin administration attenuated high glutamate concentrations. A combination of immunosuppression and upregulation of nitric oxide synthase may be useful in lowering high glutamate concentrations in ischemic CNS conditions.

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in American Journal of Veterinary Research

Abstract

Objective—To determine the protein and cellular composition of CSF in healthy adult ferrets.

Animals—42 clinically normal adult ferrets.

Procedure—CSF samples were collected from the cerebellomedullary cistern of anesthetized ferrets by use of disposable 25-gauge, 1.6-cm-long hypodermic needles. Samples were processed within 20 minutes after collection. The number of WBCs and RBCs per microliter of CSF was counted by use of a hemacytometer. The total protein concentration was determined by use of an automated chemistry analyzer.

Results—Total WBC counts (range, 0 to 8 cells/µL; mean, 1.59 cells/µL) in CSF of ferrets were similar to reference range values obtained for CSF from other species. Twenty-seven CSF samples had < 100 RBCs/µL (mean, 20.3 RBCs/µL). A small but significant effect of blood contamination on WBC counts was found between the 27 CSF samples with < 100 RBCs/µL and the remaining samples. Protein concentrations in CSF of ferrets (range, 28.0 to 68.0 mg/dL; mean, 31.4 mg/dL) were higher than has been reported for the CSF of dogs and cats. A significant effect of blood contamination on the CSF protein concentration was not found.

Conclusions and Clinical Relevance— We have established reference range values for WBC counts and protein concentrations in CSF from healthy adult ferrets that may be useful in the clinical investigation of CNS disease. Results of our study indicate that the WBC count is significantly affected by blood contamination of the CSF sample. (Am J Vet Res 2004;65:758–760)

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in American Journal of Veterinary Research

Abstract

Objective—To determine whether clinical signs or magnetic resonance imaging findings were associated with outcome in dogs with presumptive ischemic myelopathy.

Design—Retrospective case series.

Animals—50 dogs.

Procedures—Medical records and magnetic resonance images were reviewed. A neurologic score from 1 (normal) to 5 (most severe degree of dysfunction) was assigned on the basis of neurologic signs at the time of initial examination. Follow-up information was obtained from the medical records and by means of a telephone questionnaire completed by owners and referring veterinarians.

Results—Median neurologic score at the time of initial examination was 3 (range, 2 to 5). Median follow-up time was 584 days (range, 4 to 2,090 days). Neurologic score at the time of initial examination and extent of the lesion seen on magnetic resonance images (quantified as the lesion length-to-vertebral length ratio and as the percentage cross-sectional area of the lesion) were significantly associated with outcome. Sensitivity of using a lesion length-to-vertebral length ratio > 2.0 or a percentage cross-sectional area of the lesion ≥ 67% to predict an unsuccessful outcome was 100%.

Conclusions and Clinical Relevance—Results suggested that severity of neurologic signs at the time of initial examination and extent of the lesions seen on magnetic resonance images were associated with outcome in dogs with ischemic myelopathy.

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in Journal of the American Veterinary Medical Association