Abstract
Fungal detection in equine airways may be performed on either tracheal wash (TW) or bronchoalveolar lavage fluid (BALF) by either cytology or culture. However, method comparisons are sparse. Our objective was to determine the prevalence of fungi in airways of horses according to the sample site and laboratory methodology. Sixty-two adult horses, investigated in the field or referred for respiratory disease, were included. Tracheal wash, and BALF collected separately from both lungs, were collected using a videoendoscope. Fungi were detected in cytologic samples examined by light microscopy, and by fungal culture. Hay was sampled in the field. Prevalence of fungi was of 91.9% in TW and 37.1% in BALF. Fungi were cultured from 82.3% of TW and 20.9% of BALF. Fungal elements were observed cytologically in 69.4% of TW and 22.6% of BALF. In 50% of horses, the same fungi were detected in both TW and hay, but fungi detected in BALF and hay differed in all horses. Poor agreement was found for the detection of fungi between TW and BALF and between fungal culture and cytologic examination (Cohen’s kappa coefficient (κ) < 0.20). Moderate agreement was found between cytologic examination of left and right lungs (κ = 0.47). The prevalence of fungi detected cytologically on pooled BALF was significantly different (p = 0.023) than on combined left and right BALF. Fungi were more prevalent in the TW than BALF, and results suggest that hay might not be the primary source of fungi of the lower respiratory tract of horses.
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Data availability
The data that support the findings of this study are available from the corresponding author upon reasonable request.
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Acknowledgements
Preliminary results were presented to the ECEIM Virtual Congress 2021 (poster with oral communication, November 2021), the 11th ICEEP (poster, Uppsala, June 2022) and the BEVA Congress 2022 (oral presentation, Liverpool, September 2022).
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Financial support was provided by the IFCE (French Institute for Horses and Equestrians), Fonds EPERON, LABÉO and CISCO-Oniris.
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L. Lemonnier contributed to study design, data collection and study execution, data analysis and interpretation, and preparation of the manuscript. A. Couroucé contributed to study design, data collection and study execution, data analysis and interpretation and preparation of the manuscript. M. Cessans, P. Barbazanges and M.-P. Toquet contributed to data collection, study execution and data analysis. L. Petit contributed to data analysis. J.M. Cardwell contributed to study design and preparation of the manuscript. E.A. Richard contributed to study design, data analysis and interpretation, and preparation of the manuscript. All authors gave their final approval of the manuscript.
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Lemonnier, L.C., Couroucé, A., Cessans, M. et al. Detection of fungi in the airways of horses according to the sample site: a methodological study. Vet Res Commun (2023). https://doi.org/10.1007/s11259-023-10213-y
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DOI: https://doi.org/10.1007/s11259-023-10213-y