ORIGINAL RESEARCH article

Front. Vet. Sci.

Sec. Veterinary Imaging

Volume 12 - 2025 | doi: 10.3389/fvets.2025.1556943

This article is part of the Research TopicCutting-Edge Technology in Veterinary Medicine - volume IIView all articles

Electrical impedance tomography in calves with bovine respiratory disease: Correlations with clinical and blood gas findings

Provisionally accepted
Ulrich  BleulUlrich Bleul*Fabienne  KluserFabienne KluserAndress  WaldmannAndress WaldmannChristian  GerspachChristian Gerspach
  • Department of Farm Animals, Vetsuisse Faculty, University of Zurich, Zurich, Zurich, Switzerland

The final, formatted version of the article will be published soon.

Bovine respiratory disease (BRD) is a multifactorial global problem associated with long-term deleterious effects on the well-being of calves and marked financial losses. Prompt diagnosis of BRD, monitoring the success of treatment, and providing an accurate prognosis remain challenging because current methods for stall-side diagnosis are inadequate. To improve diagnosis in addition to clinical and morphological findings and gain insight into the respiratory dynamics of BRD, thoracic electrical impedance tomography (EIT) was used to evaluate calves with BRD (Group D; n=42) and healthy calves (Group H; n=13). Thoracic EIT is a non-invasive method of quantifying differences in impedance changes between various lung regions and impedance changes over time. A belt with 32 equidistantly mounted electrodes was placed around the thorax of non-sedated calves of both groups to measure impedance changes during respiration. The results were compared with the clinical findings and the California BRD scores. Compared with group H, Group D had decreased ventilation in the ventral lung regions (p = 0.05); ventilation shifted to the left lung lobes in calves with marked auscultatory changes (p = 0.013). In addition, the quartile ventilation ratio on inspiration (VQRi), used to quantify changes in impedance during inspiration, differed significantly between the two groups (p = 0.0039). Of all the EIT parameters, VQRi correlated most closely with paO2 and the A-a-gradient and was significantly lower in group D than in group H (p = 0.061). The results of EIT revealed differences in the inspiratory dynamics of clinically healthy and ill calves and correlated with the clinical and blood gas findings. Thus, EIT can be used alone or together with other diagnostic tools to identify and monitor BRD in calves.

Keywords: Electrical impedance tomography, Pneumonia, bovine, respiratory disease, Thorax, Ventilation

Received: 07 Jan 2025; Accepted: 22 Apr 2025.

Copyright: © 2025 Bleul, Kluser, Waldmann and Gerspach. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Ulrich Bleul, Department of Farm Animals, Vetsuisse Faculty, University of Zurich, Zurich, CH-8057, Zurich, Switzerland

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