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Previous Issue: Issue 23
Basal Serum Cortisol Concentration as a Screening Test for Hypoadrenocorticism in Dogs
Bovens, C., Tennant, K., Reeve, J. and Murphy, K.F. (2014) Journal of Veterinary Internal Medicine, 28: 1541–1545
Basal serum or plasma cortisol concentration has been used as a screening test for hypoadrenocorticism, particularly recently when there have been supply issues with ACTH. This study aimed to evaluate the sensitivity and specificity of basal serum cortisol to diagnose hypoadrenocorticism. 450 dogs with illness for reasons other than adrenal gland disease and 14 dogs with hypoadrenocorticism were included in this retrospective case-control study. Sensitivity and specificity were calculated, using the ACTH stimulation test as the reference test. With a cut off point of <55nmol/l, basal cortisol was 100% sensitive and 63% specific in the diagnosis of hypoadrenocorticism. With a cut off of <28nmol/l, sensitivity was 86% and specificity was 92%. The authors conclude that basal cortisol levels are a useful screening test for hypoadrenocorticism, and that the disease is unlikely with a basal cortisol of >55nmol/l. However, a low basal cortisol was not sufficient to rule the disease out.
Bottom line: Basal cortisol is a useful screening test for hypoadrenocorticism, but the diagnosis should be confirmed with an ACTH stimulation test.
Echocardiographic Findings in 11 Cats with Acromegaly
Myers, J.A., Lunn, K.F. and Bright, J.M. (2014) Journal of Veterinary Internal Medicine, 28: 1235–1238.
Acromegaly is an uncommon endocrine disorder of cats which is known to lead to cardiac sequelae. However, the echocardiographic findings in cats with acromegaly have not been well described. This retrospective study included cats with acromegaly which had been diagnosed with the disease at Colorado State University between 2008 and 2012. Of the 18 cats that had been diagnosed with the condition in this period, eleven had undergone echocardiography, and these were included in this study. 7 of these were found to have left ventricular concentric hypertrophy, 6 had left atrial enlargement, and 7 had diastolic dysfunction. All 11 cats had some evidence of cardiac disease.
Bottom line: Cardiac disease is common in cats with acromegaly, and cardiac investigations should be considered in these cases.
RADIOGRAPHIC DIAGNOSIS OF MECHANICAL OBSTRUCTION IN DOGS BASED ON RELATIVE SMALL INTESTINAL EXTERNAL DIAMETERS
Finck, C., D'Anjou, M.-A., Alexander, K., Specchi, S. and Beauchamp, G. (2014) Veterinary Radiology & Ultrasound, 55: 472–479
Radiography is a useful tool to help in the diagnosis of mechanical gastrointestinal obstruction. This retrospective study compared the findings of radiographic examination of the small intestines in dogs with and without mechanical intestinal obstruction. Fifty dogs with gastrointestinal clinical signs that had undergone abdominal radiography were selected from records. 25 were classified as obstructed and 25 as non-obstructed. The radiographs were randomised and blindly interpreted by three examiners. Parameters examined included small intestinal maximal and minimal diameters, L5 vertebral body height and a subjective assessment of intestinal dilation based on severity and distribution. Segmental dilation was found to more common in obstructed dogs. Most non-obstructed dogs had no dilation. However, subjective scores of dilation had low interobserver agreement. The study provides parameters based on various ratios to indicate the likelihood of obstruction. The authors recommended that dogs with inconclusive findings are investigated by further methods.
Bottom line: Abdominal radiography is a useful imaging modality for the diagnosis of small intestinal mechanical obstruction.
Linear versus non-linear gastrointestinal foreign bodies in 499 dogs: clinical presentation, management and short-term outcome
Hobday, M. M., Pachtinger, G. E., Drobatz, K. J. and Syring, R. S. (2014) Journal of Small Animal Practice, 55: 560–565.
This study also deals with gastro-intestinal foreign bodies, this time comparing the presentation and management of linear foreign bodies compared to non-linear foreign bodies. Linear foreign bodies are generally considered more complicated to manage than non-linear foreign bodies because of the way they extend through large sections of the gastro-intestinal tract. The study involved a retrospective review of dogs with confirmed gastro-intestinal foreign body. 176 dogs with linear foreign bodies and 323 with non-linear foreign bodies were found to be eligible for the study. Dogs with linear foreign bodies were found to be more likely to have a history of vomiting and anorexia. Compared to dogs with non-linear foreign bodies, they were more likely to have intestinal necrosis and perforation as well as peritonitis. Intestinal resection was more likely to be required in dogs with linear foreign bodies, and their hospital stays were longer. However, there was no difference in survival to discharge from hospital, with 96% achieving this in both groups. There was a small difference in treatment costs, with the linear foreign body cost being 10% higher than the non-linear foreign body cost.
Bottom line: Linear foreign bodies often require more extensive surgery than non-linear foreign bodies, but the prognosis is good in both cases.
COMPARISON OF NONCONTRAST COMPUTED TOMOGRAPHY AND HIGH-FIELD MAGNETIC RESONANCE IMAGING IN THE EVALUATION OF GREAT DANES WITH CERVICAL SPONDYLOMYELOPATHY
Martin-Vaquero, P., da Costa, R. C. and Drost, W. T. (2014) Veterinary Radiology & Ultrasound, 55: 496–505
Great Danes are predisposed to cervical spondylomyelopathy (Wobbler’s syndrome). CT and MRI have both been utilised to diagnose this condition. CT is a superior at imaging bony structures, whereas MRI is better at imaging the soft tissue and neural structures. This prospective study compared non-contrast CT with MRI in evaluation the cervical vertebral column of Great Danes with cervical spondylomyelopathy. 15 Great Danes with the condition were included in the study, and each underwent noncontrast CT under sedation and high-field MRI under general anaesthesia. Three observers independently evaluated the images, assessing changes such as site, direction and cause of compression and presence of foraminal stenosis. A high degree of agreement between MRI and CT was found for the site and direction of compression. Interobserver agreement for site of compression was also high, while the degree of articular joint proliferation had low agreement between observers. The authors concluded that there was good agreement between observers and methods for site of compression, but there was a lot of variation between the imaging methods and between the observers for factors such as the characteristics of the articular processes and the degree of foraminal stenosis.
Bottom line: MRI and CT are both accurate in the diagnosis of the site of compression in cervical spondylomyelopathy. However, agreement regarding other findings was lower.
Relationships between cerebrospinal fluid characteristics, injury severity, and functional outcome in dogs with and without intervertebral disk herniation
Levine, G. J., Cook, J. R., Kerwin, S. C., Mankin, J., Griffin, J. F., Fosgate, G. T. and Levine, J. M. (2014) Veterinary Clinical Pathology, 43: 437–446
Diagnosis of intervertebral disc herniation (IVDH) usually requires advanced imaging techniques such as CT, MRI, plain myelography or CT myelography. In many of these cases, cerebrospinal fluid (CSF) is obtained, either as part of the investigation, or incidentally at the time of myelography. This retrospective study aimed to assess the characteristics of CSF in dogs with IVDH. 727 dogs with spinal disease were included in the study, including 443 with thoracolumbar IVDH and 103 with cervical IVDH, as well as 181 with other spinal cord diseases. MRI, CSF and clinical variables were evaluated. The nucleated cell count in the CSF was found to increase in proportion to the severity of the spinal cord injury in those dogs with IVDH. The presence of hyperintensity on T2 weighted MRI scans was also associated with a higher cell count on CSF analysis in dogs with thoracolumbar IVDH. CSF protein levels and cell counts decreased as injury duration increased. However, CSF analysis was not accurate at differentiating IVDH from other spinal cord diseases.
Bottom line: CSF analysis in dogs with IVDH can provide information on severity and duration of spinal cord injury, but does not differentiate the condition from other diseases.
Food-specific serum IgE and IgG reactivity in dogs with and without skin disease: lack of correlation between laboratories
Hardy, J. I., Hendricks, A., Loeffler, A., Chang, Y.-M., Verheyen, K. L., Garden, O. A. and Bond, R. (2014) Veterinary Dermatology, 25: 447–e70.
Blood testing for dietary intolerance using food-specific serum IgE and IgG is commonly offered by commercial laboratories, but the evidence on the usefulness of the test is conflicting. There have been no prior reports on reproducibility of the tests between laboratories. This study aimed to assess the variability of test results between laboratories. Eight dogs with skin disease caused by adverse food reaction were enrolled into the study, together with 22 dogs with atopic dermatitis for non-dietary reasons, 30 dogs with an allergic phenotype, 12 dogs with miscellaneous skin diseases and 9 healthy dogs. Paired sera were submitted from each dog for food-specific IgE and IgG antibodies to two laboratories. The agreement between the two laboratories for the tests varied from fair (in four antigens) to less than chance for six antigens. The authors concluded that the tests were of limited clinical usefulness, as they did not correlate with each other, nor differentiate between dogs with different diseases.
Bottom line: Food specific IgE and IgG antibody tests may have limited clinical utility.
Canine Soft Tissue Sarcoma Managed in First Opinion Practice: Outcome in 350 Cases
Bray, J. P., Polton, G. A., McSporran, K. D., Bridges, J. and Whitbread, T. M. (2014) Veterinary Surgery, 43: 774–782
Soft tissue sarcomas are common tumours that are frequently managed in first opinion practice. This study surveyed the approach in first opinion practice to the management of soft tissue sarcoma in dogs. Questionnaires were sent to vets requesting clinical information and outcome on dogs with soft tissue sarcomas. 350 cases were included in the study. It was found that most surgeries were unplanned, with only 4% having a histological diagnosis prior to surgery, and 17% have a cytological diagnosis. Local recurrence occurred in 21% of cases. The extent of the resection was not found to be associated with recurrence or survival time. The median survival time was not reached in this study, with 70% still alive at 5 years. Smaller and discrete tumours had better survival outcomes. A higher tumour grade was associated with an increased risk of recurrence. The study found a selection bias towards management of less aggressive within first opinion practice.
Bottom line: Wide resection margins are not the main determinant of outcome in the management of soft tissue sarcomas.
Saddle fit and management: An investigation of the association with equine thoracolumbar asymmetries, horse and rider health.
L Greve and S Dyson Equine Veterinary Journal
This study investigated the prevalence of saddle slip and its association with equine and rider back pain, thoracolumbar asymmetry and equine lameness. A questionnaire survey was combined with clinical assessment which included specific examination of thoracolumbar symmetry, dynamic examination of the horse being ridden and assessment of saddle fit. There was a significant association between a recent history of lameness and rider reported saddle slip; in the clinical assessment 106 of 205 horses had evidence of lameness or gait abnormality, of which 30 had evidence of saddle slip. This association between saddle slip and specific lameness found was significant for hindlimb lameness and combined forelimb/hindlimb lameness, but was not significant for forelimb lameness and negative for horses with no lameness. 49% of horses had minor back asymmetries, and 1.5% had major asymmetry. 43% of saddles were not fitted correctly in this population. Riders using an ill-fitting saddle were significantly more likely to have back pain themselves than those using a well-fitted saddle. There was a significant association between crooked rider position and saddle slip.
Bottom line: This study addresses the important associations between rider position, saddle fit, saddle slip and rider and horse back pain; these complex interactions should be considered when investigating lameness or poor performance.
Occurrence of cardiac arrhythmias in Standardbred racehorses.
JR Slack, RC Boston, LR Soma and VB Reef Equine Veterinary Journal
This prospective observational study assessed the occurrence of cardiac arrhythmias in Standardbred racehorses both prior to racing and in the late post race period (6-29 minutes post race). A non-continuous recording device was used in this study where 8657 ECG recordings were collected from 1816 horses over a 12 week period. 87.8% of horses had normal sinus rhythm prior to racing, 6.9% had second degree AV block, with the remainder having other arrhythmias. In the post race period no horses had normal sinus rhythm, 99.4% had sinus tachycardia; 0.28% had ventricular premature depolarisation, 0.14% had atrial fibrillation, 0.14% had supraventricular premature depolarisation (s), with the remainder having other arrhythmias. There was no association between pre-race furosemide administration and post-race cardiac arrhythmia, the only risk factor identified was age.
Bottom line: The bottom line: The non continuous recording method is a practical tool to detect physiological and pathological cardiac arrhythmias; the frequency of arrhythmias detected at this time period post racing can be used to inform racecourse veterinary surgeons.