Accuracy of transcranial magnetic stimulation and a Bayesian latent class model for diagnosis of spinal cord dysfunction in horses

Background: Spinal cord dysfunction/compression and ataxia are common in horses. Presumptive diagnosis is most commonly based on neurological examination and cervical radiography, but the interest into the diagnostic value of transcranial magnetic stimulation (TMS) with recording of magnetic motor evoked potentials has increased. The problem for the evaluation of diagnostic tests for spinal cord dysfunction is the absence of a gold standard in the living animal. Objectives: To compare diagnostic accuracy of TMS, cervical radiography, and neurological examination. Animals: One hundred seventy-four horses admitted at the clinic for neurological examination. Methods: Retrospective comparison of neurological examination, cervical radiography, and different TMS criteria, using Bayesian latent class modeling to account for the absence of a gold standard. Results: The Bayesian estimate of the prevalence (95% CI) of spinal cord dysfunction was 58.1 (48.3%-68.3%). Sensitivity and specificity of neurological examination were 97.6 (91.4%-99.9%) and 74.7 (61.0%-96.3%), for radiography they were 43.0 (32.3%-54.6%) and 77.3 (67.1%-86.1%), respectively. Transcranial magnetic stimulation reached a sensitivity and specificity of 87.5 (68.2%-99.2%) and 97.4 (90.4%-99.9%). For TMS, the highest accuracy was obtained using the minimum latency time for the pelvic limbs (Youden's index = 0.85). In all evaluated models, cervical radiography performed poorest. Clinical Relevance: Transcranial magnetic stimulation-magnetic motor evoked potential (TMS-MMEP) was the best test to diagnose spinal cord disease, the neurological examination was the second best, but the accuracy of cervical radiography was low. Selecting animals based on neurological examination (highest sensitivity) and confirming disease by TMS-MMEP (highest specificity) would currently be the optimal diagnostic strategy

Accuracy and inter-rater reliability of lung auscultation by bovine practitioners when compared with ultrasonographic findings

In practice, veterinary surgeons frequently rely on lung auscultation as a confirmation test for pneumonia. To what extent diagnostic accuracy of lung auscultation varies between different practitioners is currently unknown. In this diagnostic test study, 49 Dutch veterinarians each auscultated between 8 and 10 calves, and communicated whether they would decide to treat the animal with antimicrobials or not. They were not allowed to perform any other aspect of the clinical examination. Their decisions were compared with lung ultrasonography findings. The average sensitivity and specificity of lung auscultation were 0.63 (sd=0.2; range=0.2-1.0) and 0.46 (sd=0.3; range=0.0-1.0), respectively. Of the participants, 8.2 per cent were 100 per cent sensitive, 16.3 per cent were 100 per cent specific, and only 4.0 per cent were perfect. The Krippendorff's alpha was 0.18 (95 per cent confidence interval: -0.01 to 0.38), signifying poor reliability between multiple raters. Regardless of the poor diagnostic accuracy in this study, especially the large variation in a confirmation test between different practitioners could potentially cause professional damage as well as misuse of antimicrobials. This study could be seen as a gentle stimulus to regularly evaluate one's diagnostic skills. Both complementary training and the use of more accurate techniques with less inter-rater variation could improve the situation

Bayesian evaluation of the accuracy of a thoracic auscultation scoring system in dairy calves with bronchopneumonia using a standard lung sound nomenclature

BackgroundAlthough thoracic auscultation (AUSC) in calves is quick and easy to perform, the definition of lung sounds is highly variable and leads to poor to moderate accuracy in diagnosing bronchopneumonia (BP). Hypothesis/ObjectivesEvaluate the diagnostic accuracy of an AUSC scoring system based on a standard lung sound nomenclature at different cut-off values, accounting for the absence of a gold standard test for BP diagnosis. AnimalsThree hundred thirty-one calves. MethodsWe considered the following pathological lung sounds: increased breath sounds (score 1), wheezes and crackles (score 2), increased bronchial sounds (score 3), and pleural friction rubs (score 4). Thoracic auscultation was categorized as AUSC1 (positive calves for scores & GE;1), AUSC2 (positive calves for scores & GE;2), and AUSC3 (positive calves for scores & GE;3). The accuracy of AUSC categorizations was determined using 3 imperfect diagnostic tests with a Bayesian latent class model and sensitivity analysis (informative vs weakly informative vs noninformative priors and with vs without covariance between ultrasound and clinical scoring). ResultsBased on the priors used, the sensitivity (95% Bayesian confidence interval [BCI]) of AUSC1 ranged from 0.89 (0.80-0.97) to 0.95 (0.86-0.99), with a specificity (95% BCI) of 0.54 (0.45-0.71) to 0.60 (0.47-0.94). Removing increased breath sounds from the categorizations resulted in increased specificity (ranging between 0.97 [0.93-0.99] and 0.98 [0.94-0.99] for AUSC3) at the cost of decreased sensitivity (0.66 [0.54-0.78] to 0.81 [0.65-0.97]). Conclusions and Clinical ImportanceA standardized definition of lung sounds improved AUSC accuracy for BP diagnosis in calves

Ultrasonographic Thicknesses of Ruminal and Abdominal Wall in High Yielding Holstein Dairy Cows

Abstract: Ultrasonography has been used as a non invasive method for examination of gastrointestinal tract of cattle. Rumen status and rumen health are importance in high producing dairy herds. In this study the normal values of abdominal and ruminal wall thickness in mid lactation cows were measured and abnormal cases were evaluated with ultrasonography. On ultrasonogram, ruminal wall in all of the cases were constituted by two layers but in some cases such as fluid accumulation or ascite were imaged as three layers. The mean ± standard deviation of abdominal and ruminal wall thickness (two layers) were 17.31 ± 3.08 and 8.01 ± 1.36 milimeters respectively. So, ultrasonographic investigation of left abdomen and their values of the thicknesses could be a part of rumen health evaluation in dairy herds but more researchs should be done for this matter in high producing dairy herds