Objective—To determine whether sensitivity of
detecting an anomalous portosystemic blood vessel
during operative mesenteric portography varied with
Animals—34 dogs with a portosystemic shunt diagnosed
via scintigraphy or surgery.
Procedure—Portograms were evaluated for a portosystemic
blood vessel. Sensitivity was calculated
from results obtained with dogs in left lateral, right lateral,
and dorsal recumbency and from results
obtained with dogs in 2 or 3 positions. Differences in
sensitivity among positions and between 2 examiners
Results—Sensitivity was 85, 91, and 100% in dorsal,
right lateral, and left lateral recumbency, respectively.
Sensitivity was lower in dorsal recumbency than in left
lateral recumbency, although differences were not significant.
There was no significant difference between
sensitivity of results obtained in dorsal and right lateral
recumbency or right lateral and left lateral recumbency.
Sensitivity for combined right lateral and dorsal
positions was 97%, which was better than that in dorsal
recumbency alone, although the difference was
not significant. Because sensitivity in left lateral
recumbency was 100%, there was no need to evaluate
the improvement obtained by combining the result
of this position with the results of other positions.
Conclusion and Clinical Relevance—Results of
mesenteric portography varied with patient positioning.
The optimal position varied among patients but
left lateral recumbency may be better and dorsal
recumbency worse. Sensitivity may be improved by
performing the test with the patient in orthogonal
recumbent positions. (J Am Vet Med Assoc 2001;
Objective—To assess agreement between a commercially available Geiger-Meuller (GM) survey meter and millirem tissue-equivalent (TE) meter for measuring radioactivity in cats treated with sodium iodine I 131 (131I).
Animals—15 cats with hyperthyroidism and undergoing 131I treatment.
Procedures—Duplicate measurements were obtained at a distance of 30 cm from the thyroid region of each cat's neck by 2 observers who used both meters on day 3 or 5 after131I administration. Comparisons of measurements between meters and observers were made, with limits of agreement defined as the mean difference ± 2 SDs of the differences.
Results—For observer 1, the mean of the differences in the 2 meters' measurements in all cats was 0.012 mSv/h (SD, 0.011 mSv/h). For observer 2, the mean of the differences in measurements was 0.012 mSv/h (SD, 0.010 mSv/h). For the GM meter, the mean of the differences of the 2 observers for all cats was 0.003 mSv/h (SD, 0.011 mSv/h). For the TE meter, the mean of the differences of the 2 observers for all cats was 0.003 mSv/h (SD, 0.007 mSv/h).
Conclusions and Clinical Relevance—Results indicate that there was considerable agreement between meters and observers in measurements of radioactivity in cats treated with 131I. Measurements obtained by use of the GM meter may be approximately 0.01 mSv/h less than or 0.03 mSv/h higher than those obtained with the TE meter. If this range is acceptable for an institution's release criteria, the 2 meters should be considered interchangeable and acceptable for clinical use.
Objective—To determine whether frontal-sinus size is associated with syringohydromyelia.
Sample Population—Medical records and magnetic resonance images of 62 small-breed dogs.
Procedures—Medical records and magnetic resonance images were reviewed retrospectively for evaluation of frontal-sinus size and syringohydromyelia. A Yates-corrected 2-tailed χ2 test was used to determine whether an association existed between absent or miniscule frontal sinuses and syringohydromyelia. The strength of the association was evaluated by means of prevalence and odds ratios.
Results—Absent or miniscule air-filled frontal sinuses were detected in 28 of 62 (45%) dogs, and syringohydromyelia was detected in 12 of 62 (19%) dogs. Syringohydromyelia was detected in 10 of 28 dogs with absent or miniscule frontal sinuses (prevalence, 36%; 95% confidence interval, 16% to 55%) and in 2 of 34 dogs with larger frontal sinuses (prevalence, 6%; confidence interval, 0% to 15%). The probability of detecting syringohy-dromyelia in dogs with absent or miniscule air-filled frontal sinuses was significantly greater than the probability of detecting it in dogs with larger frontal sinuses. The prevalence ratio was 6.1, and the odds ratio was 8.9.
Conclusions and Clinical Relevance—An association between frontal-sinus size and syringohydromyelia was identified in small-breed dogs, suggesting that the pathogenesis of syringohydromyelia in some instances may involve abnormal development of the entire or supratentorial part of the cranium, as opposed to being limited to the infratentorial part.
Objective—To compare estimation of glomerular filtration rate determined via conventional methods (ie, scintigraphy and plasma clearance of technetium Tc 99m pentetate) and dynamic single-slice computed tomography (CT).
Animals—8 healthy adult cats.
Procedures—Scintigraphy, plasma clearance testing, and dynamic CT were performed on each cat on the same day; order of examinations was randomized. Separate observers performed GFR calculations for scintigraphy, plasma clearance testing, or dynamic CT. Methods were compared via Bland-Altman plots and considered interchangeable and acceptable when the 95% limits of agreement (mean difference between methods ± 1.96 SD of the differences) were ≤ 0.7 mL/min/kg.
Results—Global GFR differed < 0.7 mL/min/kg in 5 of 8 cats when comparing plasma clearance testing and dynamic CT; the limits of agreement were 1.4 and −1.7 mL/min/kg. The mean ± SD difference was −0.2 ± 0.8 mL/min/kg, and the maximum difference was 1.6 mL/min/kg. The mean ± SD difference (absolute value) for percentage filtration by individual kidneys was 2.4 ± 10.5% when comparing scintigraphy and dynamic CT; the maximum difference was 20%, and the limits of agreement were 18% and 23% (absolute value).
Conclusions and Clinical Relevance—GFR estimation via dynamic CT exceeded the definition for acceptable clinical use, compared with results for conventional methods, which was likely attributable to sample size and preventable technical complications. Because 5 of 8 cats had comparable values between methods, further investigation of dynamic CT in a larger sample population with a wide range of GFR values should be performed.
Objective—To evaluate factors associated with survival in dogs with nasal carcinomas that did not receive treatment or received only palliative treatment.
Design—Retrospective case series.
Animals—139 dogs with histologically confirmed nasal carcinomas.
Procedures—Medical records, computed tomography images, and biopsy specimens of nasal carcinomas were reviewed. Only dogs that were not treated with radiation, surgery, chemotherapy, or immunotherapy and that survived ≥ 7 days from the date of diagnosis were included. The Kaplan-Meier method was used to estimate survival time. Factors potentially associated with survival were compared by use of log-rank and Wilcoxon rank sum tests. Multivariable survival analysis was performed by use of the Cox proportional hazards regression model.
Results—Overall median survival time was 95 days (95% confidence interval [CI], 73 to 113 days; range, 7 to 1,114 days). In dogs with epistaxis, the hazard of dying was 2.3 times that of dogs that did not have epistaxis. Median survival time of 107 dogs with epistaxis was 88 days (95% CI, 65 to 106 days) and that of 32 dogs without epistaxis was 224 days (95% CI, 54 to 467 days).
Conclusions and Clinical Relevance—The prognosis of dogs with untreated nasal carcinomas is poor. Treatment strategies to improve outcome should be pursued.
Objective—To compare signalment of horses with cervical vertebral malformation-malarticulation (CVM) with that of control horses and to describe results of clinical examination, diagnostic imaging and necropsy findings, and reported outcome in horses with CVM.
Design—Retrospective case-control study.
Animals—270 horses with CVM and 608 control horses admitted to 6 veterinary hospitals from 1992 through 2007.
Procedures—Medical records of participating hospitals were reviewed to identify horses with CVM (ie, case horses) and contemporaneous control (non-CVM-affected) horses that were admitted for treatment. Signalment was compared between case horses and control horses. Results of clinical examination, laboratory and diagnostic imaging findings, necropsy results, and outcome were assessed for horses with CVM.
Results—Case horses were younger (median age, 2 years) than were control horses (median age, 7 years). Thoroughbreds, warmbloods, and Tennessee Walking Horses were overrepresented in the CVM group. Gait asymmetry and cervical hyperesthesia were frequently detected in horses with CVM. Vertebral canal stenosis and articular process osteophytosis were commonly observed at necropsy; agreement between the results of radiographic or myelographic analysis and detection of lesions at necropsy was 65% to 71% and 67% to 78%, respectively. Of 263 horses with CVM for which outcome was recorded, 1 died and 172 (65.4%) were euthanatized.
Conclusions and Clinical Relevance—Odds of a diagnosis of CVM were greater in young horses and horses of specific breeds. Detection of gait asymmetry and cervical hyperesthesia were frequently reported in association with CVM. Accurate diagnosis of lesions associated with CVM by use of radiography and myelography can be challenging. (J Am Vet Med Assoc 2010;237:812-822)