Thiopental is an excellent choice for evaluation of laryngeal function. Unfortunately, thiopental is no longer manufactured. In its absence, the ideal anesthetic protocol for laryngoscopy has not been determined. Propofol and propofol/ketamine were compared for the evaluation of laryngeal function in 48 healthy dogs. Laryngeal exposure was moderate to excellent in all dogs and not significantly different between protocols. Saturation of peripheral O2 (SPO2) readings were decreased in the propofol/ketamine group, and deeper respirations were more likely to correlate with normal laryngeal function regardless of treatment group. Doxapram was administered to apneic patients to stimulate respiration and allow for evaluation of laryngeal function. No significant difference in frequency of doxapram administration between groups was noted. Doxapram resulted in higher respiratory scores and significantly increased the ability to determine normal laryngeal function. Ketamine did not allow for a reduction in propofol dose and caused increased respiratory depression, making ketamine a poor addition to propofol for laryngeal function examination. Regardless of the protocol used, laryngeal function should be determined in conjunction with the respiratory phase and depth of respirations. Patients with either absent or shallow respirations should receive doxapram for accurate evaluation of laryngeal function.

Background and objectives:Intervertebral disc herniation is a common disease in chondrodystrophic dogs, and a similar neurologic condition also occurs in humans. Percutaneous laser disc ablation (PLDA) is a minimally invasive procedure used increasingly for prevention of disc herniation. PLDA is performed on thoracolumbar discs to which the same laser energy is applied regardless of their mineral content. Knowledge of individual disc mineral composition would allow laser energy dosage adjustments and more accurate treatment of degenerative discs. Usually, PLDA is guided by radiography/fl uoroscopy, which has a limited sensitivity of approximately 60 % for identifi cation of mineralized discs. An imaging or sensing technology that provides a more accurate pre-operative in-situ assessment of the disc mineralization, and potentially rapid post-operative feedback, could optimize the outcome of the PLDA procedure. A sensing technology of needle-probing single-fi ber refl ectance (SFR) spectroscopy is therefore proposed that is considered to be compatible with PLDA work fl ow. The objective of this study was to demon strate the feasibility of this technology in assessing the increased light scattering associated with mineralization in intervertebral discs in chondrodystrophoid canine species. Materials and methods: A pilot study was performed on a total of 21 intervertebral discs from two cadaveric dogs ( " Dog A " and " Dog B " ). The discs were imaged by computed tomography (CT), radiography, and SFR spectroscopy, before histopathologic examination. SFR spectroscopy in the visible/near-infrared band was performed on the nucleus pulposus of the intervertebral disc through a 20-gauge spinal needle placed percutaneously for PLDA. A normalization method was applied to the raw remission spectra to extract a dimension-less and wavelength-dependent intensity profi le in the 500 -950 nm spectral range. Results: In total, six discs were determined to be degenerative on histopathology, fi ve discs of " Dog A " and one disc of " Dog B " . CT diagnosed all six degenerated discs, whereas radiography missed two of the fi ve degenerated discs of " Dog A " . The wavelength-dependent mean scattering intensity profi les of the six degenerated discs were noticeably higher than the mean scattering intensity profi les of the 15 " normal " or insignifi cantly mineralized discs over the entire spectral range. The mean scattering intensities, averaged over each of the entire profi les, were 2.79 ± 0.58 (mean ± SD) for the six degenerated discs and 1.48 ± 0.37 for the 15 " normal " or insignifi cantly mineralized discs. A two-sample t -test showed p < 0.001 for the difference of the averaged scattering intensity between these both groups of discs. Conclusions: SFR spectroscopy measurements indicate that the increase of light scattering intensity across the entire 500 -950 nm spectral range is associated with the mineralization in canine intervertebral discs. However, the scattering characteristics of the nucleus pulposus measured in this stu...

Percutaneous SfRS may be useful as an in situ sensing tool for assessing the level of mineral degeneration in intervertebral discs for the prospect of disc-specific dosage adjustment in PLDA.

Extrusion or protrusion of an intervertebral disc is a common, frequently debilitating, painful, and sometimes fatal neurologic disease in the chondrodystrophic dog (dachshund, Pekingese, etc.). A similar condition of intervertebral disc degeneration with extrusion/protrusion is also a relatively common neurologic condition in human patients. Degeneration of the relatively avascular chondrodystrophoid intervertebral disc is associated with loss of water content, increased collagen, and deposits of calcified mineral in the nucleus pulposus. Current diagnostic methods have many limitations for providing accurate information regarding disc composition in situ prior to surgical intervention. Disc composition (i.e., mineralization), can influence the type of treatment regime and potentially prognosis and recurrence rates. The objective of this study is to investigate the feasibility of using a fiber-needle spectroscopy sensor to analyze the changes of tissue compositions involved in the chondrodystrophoid condition of the canine intervertebral disc. The nucleous pulposus, in which the metaplastic process / degeneration develops, is approximately 2mm thick and 5mm in diameter in the dachshund-sized dog. It lies in the center of the disc, surrounded by the annulus fibrosis and is enclosed by cartilaginous vertebral endplates cranially and caudally. This "shallow-and-small-slab" geometry limits the configuration of a fiber probe to sense the disc tissue volume without interference from the vertebrae. A single-fiber sensor is inserted into a 20 gauge myelographic spinal needle for insertion into the disc in situ and connected via a bifurcated fiber to the light source and a spectrometer. A tungsten light source and a 940nm light-emitting-diode are combined for spectral illumination covering VIS/NIR with expected improved sensitivity to water. Analysis of the reflectance spectra is expected to provide information of scattering and absorption compositions of tissue in proximity to the fiber-tip. Preliminary measurements on cadaveric canine intervertebral discs indicated significant reduction of scattering constituents and possible diminishment of water content after percutaneous laser disc ablation (PLDA). This fiber-needle based sensing configuration may be feasible for integrating the evaluation of calcification and water content into the work-flow of holmium:YAG laser disc ablation for pre-operative in-line detection and post-operative evaluation of therapeutic interventions regarding the chondrodystrophic disc.

HistoryAn 8-year-old neutered male Dachshund was evaluated at the Boren Veterinary Medical Teaching Hospital with a history of stranguria, pollakiuria, and incontinence for 3 weeks and signs of back pain and slowly progressive paraparesis for 2 weeks. The dog had been treated for cystitis and suspected prostatitis by the referring veterinarian, with a 1-week course of antimicrobials and meloxicam. The urinary incontinence persisted after treatment, but there was mild improvement in the stranguria and pollakiuria and a subjective decrease in the size of the prostate gland. Approximately 2 years earlier, a T12-T13 hemilaminectomy had been performed for treatment of Hansen type 1 intervertebral disk herniation. The signs of back pain and progressive paraparesis were believed to be the result of an episode of intervertebral disk disease, and cage confinement was initiated. Three days prior to referral, administration of meloxicam was discontinued, and treatment with tramadol and prednisone was initiated. The owner reported that the dog had been dribbling urine, was only able to urinate and defecate small amounts at a time, had begun trying to bite when picked up, and was weak in the pelvic limbs.Physical examination revealed severe signs of pain in the lumbar vertebral area and caudal aspect of the abdomen, an asymmetrically enlarged and painful prostate gland, pelvic limb paraparesis, conscious proprioceptive deficits in the pelvic limbs, and pelvic limb hyperreflexia. Anal tone and perineal reflexes were normal; the urinary bladder was distended, and urine was difficult to express. Abdominal radiography was performed to evaluate the prostate gland (Figure 1).Determine whether additional imaging studies are required, or make your diagnosis from Figure 1-then turn the page → Figure 1-Lateral (A) and ventrodorsal (B) radiographic views of the abdomen of an 8-year-old neutered male Dachshund evaluated because of a 3-week history of stranguria, pollakiuria, and signs of pain on palpation over the lumbar vertebral area (L3-L4 region).