# Cyranose® 320 eNose Effectively Differentiates Pre- and Post-Challenge Respiratory Samples in an Induced Bovine Respiratory Disease Model

## TL;DR

A handheld electronic nose can accurately detect pneumonia in cattle using nasal swabs, offering a promising tool for early diagnosis and improved animal care.

## Contribution

The study demonstrates the effectiveness of the Cyranose® 320 eNose in differentiating pre- and post-challenge respiratory samples in a bovine pneumonia model.

## Key findings

- The eNose accurately classified pre-challenge nasal swab samples with 93.5% accuracy.
- Post-challenge classification accuracy was 97.8% for nasal swabs but dropped to 72.5% for expired air samples.
- Nasal swabs were identified as the optimal sample type for eNose use due to higher accuracy and ease of collection.

## Abstract

Diagnostic tools that can accurately detect pneumonia in cattle on-farm and provide early, consistent, and easy-to-interpret results are sparse. This study tested a handheld electronic nose (eNose) to determine its capability in accurately diagnosing cattle experimentally infected with a common virus and bacteria of cattle pneumonia. Additionally, multiple sampling methods were tested to determine the optimum sample type for use on the eNose. When samples collected from animals are tested on the eNose, the device provides a single result related to the pneumonia status of the animal, making implementation on-farm straightforward for the device operator. Results showed that the eNose was able to accurately classify animals based on their pneumonia status. Nasal swab samples were the ideal sample type for use on the eNose due to better accuracy and ease of use. The eNose’s ability to provide accurate and easy-to-interpret results related to pneumonia status have the potential to promote better antimicrobial stewardship and animal welfare through consistent and early detection of this disease.

Field-based diagnostic technologies which aid in the early detection of bovine respiratory disease (BRD) are of great need, given the rising attention related to animal welfare and antimicrobial stewardship. This induced BRD study followed 12 Holstein calves through pre-challenge (day 1–3) and post-challenge (day 6–13) periods with daily sampling of nasal secretions with nasal swabs and expired air with air collection bags for determination of BRD status by use of an electronic nose (eNose). Animals were challenged with bovine herpes virus-1 (BHV-1) on day 3 following sample collection and Mannheimia haemolytica on day 5. Results demonstrated a high degree of accuracy for the eNose in correctly classifying pre-challenge samples for nasal swabs (93.5%) and expired air (96.8%). Post-challenge correct classification by the eNose was 97.8% for nasal swabs and 72.5% for expired air samples. Logistical regression was used to determine the probability of agreement between eNose classification and actual animal BRD status by study day. The largest discrepancy between nasal swab and expired air samples fell on days 6 and 7, immediately following the bacterial challenge. The eNose demonstrated potential as a field-based diagnostic tool for the detection of BRD with nasal swabs as the optimal sample type.