Incremental Value (Bayesian Framework) of Thoracic Ultrasonography over Thoracic Auscultation for Diagnosis of Bronchopneumonia in Preweaned Dairy Calves.
BACKGROUND
Thoracic ultrasonography (TUS) is a specific and relatively sensitive method to diagnose bronchopneumonia (BP) in dairy calves. Unfortunately, as it requires specific training and equipment, veterinarians typically base their diagnosis on thoracic auscultation (AUSC), which is rapid and easy to perform.


OBJECTIVE
We hypothesized that the use of TUS, in addition to AUSC, can significantly increase accuracy of BP diagnosis. Therefore, the objectives were to (i) determine the incremental value of TUS over AUSC for diagnosis of BP in preweaned dairy calves and (ii) assess diagnostic accuracy of AUSC.


METHODS
Two hundred and nine dairy calves (<1 month of age) were enrolled in this cross-sectional study.


METHODS
Prospective cross-sectional study. All calves from a veal calves unit were examined (independent operators) using the Wisconsin Calf Respiratory Scoring Criteria (CRSC), AUSC, and TUS. A Bayesian latent class approach was used to estimate the incremental value of AUSC over TUS (integrated discrimination improvement [IDI]) and the diagnostic accuracy of AUSC.


RESULTS
Abnormal CRSC, AUSC, and TUS were recorded in 3.3, 53.1, and 23.9% of calves, respectively. AUSC was sensitive (72.9%; 95% Bayesian credible interval [BCI]: 50.1-96.4%), but not specific (53.3%; 95% BCI: 43.3-64.0%) to diagnose BP. Compared to AUSC, TUS was more specific (92.9%; 95% BCI: 86.5-97.1%), but had similar sensitivity (76.5%; 95% BCI: 60.2-88.8%). The incremental value of TUS over AUSC was high (IDI = 43.7%; 5% BCI: 22.0-63.0%) significantly improving proportions of sick and healthy calves appropriately classified.


CONCLUSIONS
The use of TUS over AUSC significantly improved accuracy of BP diagnosis in dairy calves.
Department of Clinical Science, Faculté de Médecine Vétérinaire, Université de Montréal, St-Hyacinthe, QC, Canada.
S
S
Buczinski
Department of Clinical Science, Faculté de Médecine Vétérinaire, Université de Montréal, St-Hyacinthe, QC, Canada.
J
J
Ménard
Department of Production Animal Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada.
E
E
Timsit
D000818:Animals; D001314:Auscultation / Q000662:veterinary*; D001499:Bayes Theorem; D001996:Bronchopneumonia / Q000175:diagnosis / Q000662:veterinary*; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis*; D003430:Cross-Sectional Studies; D014463:Ultrasonography / Q000662:veterinary*
Bovine respiratory disease; Calf pneumonia; Diagnostic tests; Integrated discrimination improvement; Latent class model