Treatment of traumatic cervical myelopathy with surgery, prolonged positive-pressure ventilation, and physical therapy in a dog

CASE DESCRIPTION: A 9-year-old dog was evaluated for traumatic cervical myelopathy after a surgical attempt to realign and stabilize the C2 and C3 vertebrae. CLINICAL FINDINGS: The dog could not ventilate spontaneously and was tetraplegic; positive-pressure ventilation (PPV) was maintained. Myelography and computed tomography revealed spinal cord compression with subluxation of the C2 and C3 vertebrae and extrusion of the C2-3 intervertebral disk. TREATMENT AND OUTCOME: Surgically, the protruding disk material was removed and the vertebrae were realigned with screws and wire. For PPV, assist control ventilation in volume control mode and then in pressure control mode was used in the first 6 days; this was followed by synchronized intermittent mandatory ventilation until 33 days after the injury; then only continuous positive airway pressure was provided until the dog could breathe unassisted, 37 days after the injury. Physical therapy that included passive range of motion exercises, neuromuscular electrical stimulation, and functional weight-bearing positions was administered until the dog was discharged 46 days after injury; the dog was severely ataxic and tetraparetic but could walk. Therapy was continued at home, and 1 year later, the dog could run and had moderate ataxia and tetraparesis. CLINICAL RELEVANCE: Hypoventilation with tetraparesis in traumatic spinal cord injury can be successfully treated with PPV exceeding 30 days, surgery, and physical therapy.     

Effects of porcine small intestinal submucosa on elution characteristics of gentamicin-impregnated plaster of Paris

OBJECTIVE: To evaluate effects of small intestinal submucosa (SIS) on elution properties of plaster of Paris (POP). SAMPLE POPULATION: 27 POP cylinders, 27 POP spheres, and 9 polymethylmethacrylate (PMMA) spheres. PROCEDURES: Pellets were loaded with gentamicin (50 mg/g) and divided into 7 groups of 9 beads each: PMMA spheres; POP cylinders coated with 0, 4, or 8 layers of SIS; and POP spheres coated with 0, 4, or 8 layers of SIS. Gentamicin concentration was measured 6, 12, 18, 24, 32, 40, and 48 hours and 3, 4, 5, 7, 14, 21, 28, 35, and 42 days after wrapping. Porosity was evaluated via scanning electron microscopy. Curvature factor of elution curves, total amount of drug released (TDR), time required to reach 50% of total release (TDR(t50)), and number of days with concentrations > or = 1 microg/mL were compared among groups. RESULTS: SIS decreased the curvature factor and increased the TDR(t50) and TDR of POP spheres and cylinders. Curvature factor of the PMMA-release curve remained lower than that for any POP group, but all POP groups wrapped in SIS released more gentamicin than PMMA spheres. Gentamicin concentrations remained > or = 1 microg/mL in SIS-wrapped POP and PMMA groups throughout the study. Wrapping POP in SIS minimized the increase in porosity of pellets. CONCLUSIONS AND CLINICAL RELEVANCE: Wrapping POP with SIS slows the release and increases the amount of gentamicin leaching from spheres and cylinders. All groups wrapped in SIS maintained antimicrobial concentrations greater than the minimum inhibitory concentration of most pathogens.     

A simple formula for predicting claw volume of cattle

The object of this study was to develop a simple method for accurately calculating the volume of bovine claws under field conditions. The digits of 30 slaughterhouse beef cattle were examined and the following four linear measurements taken from each pair of claws: (1) the length of the dorsal surface of the claw (Toe); (2) the length of the coronary band (CorBand); (3) the length of the bearing surface (Base); and (4) the height of the claw at the abaxial groove (AbaxGr). Measurements of claw volume using a simple hydrometer were highly repeatable (r(2)= 0.999) and could be calculated from linear measurements using the formula:Claw Volume (cm(3)) = (17.192 x Base) + (7.467 x AbaxGr) + 45.270 x (CorBand) - 798.5This formula was found to be accurate (r(2)= 0.88) when compared to volume data derived from a hydrometer displacement procedure. The front claws occupied 54% of the total volume compared to 46% for the hind claws.     

Management of cervical spondylopathy-associated intervertebral, disc protrusions using metal washers in 78 dogs

Intervertebral 7.5 mm (n = 75) and 6.0 mm (n = 22) metal washers were used to distract intervertebral spaces in 78 consecutive cases of canine cervical spondylopathy-associated disc protrusions, where myelography had demonstrated traction-responsive spinal cord compression. Nineteen dogs had compressive lesions at two sites. Fifty lesions were evaluated myelographically on immediate postoperative radiographs; of these, 32 compressions had been eliminated and 18 had been reduced. Euthanasia was performed in nine dogs within six months of surgery and 15 dogs had varying degrees of neck pain during this period. Long-term follow-up information was available on 65 dogs nine to 70 months following surgery (median 32 months). Sixty-three of these dogs improved postoperatively. Neurological function subsequently deteriorated in 17 dogs 10 to 59 months following surgery (median 34 months). Eight of these 17 cases had further myelographic investigations and all had additional disc protrusions with no evidence of cord compression at the previous sites of surgery. The remaining nine cases had a deterioration in hindlimb function but were not investigated further.     

Exudative epidermitis in pigs caused by toxigenic Staphylococcus chromogenes

Staphylococcus chromogenes is closely related to Staphylococcus hyicus, which is recognised as the causative agent of exudative epidermitis (EE) in pigs. S. chromogenes is part of the normal skin flora of pigs, cattle and poultry and has so far been considered non-pathogenic to pigs. A strain of S. chromogenes producing exfoliative toxin type B, ExhB, was identified by the use of a multiplex PCR specific for the exfoliative toxins from S. hyicus. The exfoliative toxin from S. chromogenes reacted in immunoblot analysis with polyclonal and monoclonal antibodies specific to ExhB from S. hyicus and had an apparent molecular weight of 30 kDa. Sequencing the gene encoding the exfoliative toxin from S. chromogenes revealed that the molecular weight of the toxin with the signal peptide and the mature toxin was 30,553 and 26,694 Da, respectively. Comparison of the exhB genes from S. chromogenes strain VA654 and S. hyicus strain 1289D-88 showed differences in seven base pairs of the DNA sequences and in two amino acid residues in the deduced amino acid sequences. Pigs were experimentally inoculated with S. chromogenes strain VA654. By clinical observations and histopathological evaluation of the skin alterations, all pigs revealed development of generalized exudative epidermitis. No toxin producing S. hyicus was isolated from the pigs and all ExhB-positive bacterial isolates were identified as S. chromogenes. This confirmed that the disease-causing agent was the inoculated S. chromogenes strain VA654. The results of this study show that S. chromogenes may cause exudative epidermitis in pigs.     

Determination of tumor necrosis factor-alpha responsiveness in piglets around weaning using an ex vivo whole blood stimulation assay

Ex vivo whole blood stimulation with endotoxin has proved to be a useful method for quantitative evaluations of the pro-inflammatory cytokine tumor necrosis factor alpha (TNF-alpha) response ability in humans. In the present study, a dose- and time-response study was carried out in order to develop an ex vivo whole blood stimulation assay for the quantification of TNF-alpha production in pigs. The TNF-alpha response was enhanced with increasing endotoxin stimulation dose. The maximum TNF-alpha response occurred after 2-8 h of stimulation. Subsequently, the assay was used to evaluate the TNF-alpha response in pigs (n=32) in relation to weaning. The TNF-alpha response was 332 pg ml(-1) (+/-59 pg) plasma 2 days before weaning and 127 pg ml(-1) (+/-23 pg) plasma 2 days after weaning, which was a significant reduction (p<0.001). Total and differential counts of leucocytes were the same before and after weaning. Thus the lower TNF-alpha response may be due to reduced monocyte responsiveness to the endotoxin, rather than caused by a reduction in monocyte numbers. The reduced TNF-alpha response in piglets after weaning may be a factor of importance to the increased disease susceptibility seen in piglets in this period.     

Vitamin D status of wild Ricord's iguanas (Cyclura ricordii) and captive and wild rhinoceros iguanas (Cyclura cornuta cornuta) in the Dominican Republic.

Calcidiol (25-hydroxyvitamin D) values are reported for 22 wild Ricord's iguanas (Cyclura ricordii) and seven wild rhinoceros iguanas (Cyclura cornuta cornuta). Calcitriol (1,25-hydroxyvitamin D) values are reported for 12 wild Ricord's iguanas and seven wild rhinoceros iguanas. These animals were captured as part of a larger health assessment study being conducted on Ricord's iguanas in Isla Cabritos National Park, Dominican Republic. A total of 13 captive rhinoceros iguanas held outdoors at Parque Zoológico Nacional were also sampled for comparison. Mean concentrations of 25-hydroxyvitamin D were 554 nmol/L (222 ng/ml) with a range of 250-1,118 nmol/L (100-448 ng/ml) for wild Ricord's iguanas, 332 nmol/L (133 ng/ml) with a range of 260-369 nmol/L (104-148 ng/ml) for wild rhinoceros iguanas, and 317 nmol/L (127 ng/ml) with a range of 220-519 nmol/L (88-208 ng/ml) for captive rhinoceros iguanas. On the basis of these results, serum concentrations of at least 325 nmol/L (130 ng/ml) for 25-hydroxyvitamin D should be considered normal for healthy Ricord's and rhinoceros iguanas.