title: Thoracoscopy as a safe and effective technique for exploring calves affected with bovine respiratory disease.
abstract: BACKGROUND
  Bovine respiratory disease (BRD) is one of the leading causes of economic losses in the beef and dairy industry. Reliable antemortem tools for diagnosing BRD would improve the efficacy of treatment and reduce costs. Here we examined whether the relatively simple technique of thoracoscopy can support BRD diagnosis under field conditions. We also compared various equipment set-ups in order to optimize the safety and efficacy of the procedure. A total of 24 thoracoscopic procedures were performed in 17 calves diagnosed with BRD and in 2 healthy control calves. Rigid and flexible endoscopes and industrial videoscopes were tested using various insertion approaches. The suitability of the technique was assessed in terms of duration, volume of air extracted, visualization score, and image quality. Safety was assessed in terms of rectal temperature, body weight, breaths/min, presence of fibrinogen, pain score, recovery time, intraoperative complications and risk of laceration or threatening collapse.
  
  
  RESULTS
  Insertion of a flexible endoscope via a right, dorso-caudal approach at the 5thintercostal space allowed complete examination of the right lung in 15 min, as well as identification of main lung lesions and adherences in calves with BRD, without compromising calf welfare. While the dorso-caudal approach was optimal, it was associated with substantial discomfort when rigid endoscopes were used, minimal complications or mortality due to thoracoscopy were observed up to 28 days after the procedure. Videoscopes were as safe and easy to use as endoscopes, but endoscopes provided better image quality.
  
  
  CONCLUSIONS
  This study provides the first field evidence that thoracoscopy can be safe to explore BRD-diseased calves. These results justify a larger study to rigorously assess the diagnostic performance of the technique.
authors.affiliation: TRIALVET S.L. C/Encina 22, 28721 Madrid, Spain.
authors.forename: Natividad
authors.initials: N
authors.lastname: Perez-Villalobos
authors.affiliation: Veterinary Practitioner: C/Foresta 42, 28760 Madrid, Spain.
authors.forename: Iñaki
authors.initials: I
authors.lastname: Espinosa-Crespo
authors.affiliation: VES S.L. C/Ferraz 31, 28008 Madrid, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Sampayo-Cabrera
authors.affiliation: TRIALVET S.L. C/Encina 22, 28721 Madrid, Spain ; Facultad Veterinaria (UCM), Avda Pta de Hierro s/n, 28040 Madrid, Spain.
authors.forename: Juan-Vicente
authors.initials: JV
authors.lastname: González-Martín
authors.affiliation: Departamento Reproducción Animal (INIA), Avda Pta de Hierro s/n, 28040 Madrid, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Gonzalez-Bulnes
authors.affiliation: Departamento Reproducción Animal (INIA), Avda Pta de Hierro s/n, 28040 Madrid, Spain.
authors.forename: Susana
authors.initials: S
authors.lastname: Astiz
keywords: Bovine Respiratory Disease; Calves; Field conditions; Suitability; Thoracoscopy