Exhaled carbon monoxide as a marker for lower airway inflammation in thoroughbred racehorses

M.P. Cathcart, S. Love, T.D.H. Parkin, Kristopher Hughes, D.G.M. Sutton

    Research output: Other contribution to conferenceAbstractpeer-review


    The aim of the study was to investigate whether associations exist between established markers of lower airway inflammation(LAI) and biomarkers in exhaled breath (EB), namely exhaled nitric oxide (eNO), exhaled carbon monoxide (eCO) and exhaled breath condensate pH (EBC pH). A convenience sample of Thoroughbred racehorses presenting with poor performance and a clinical indication for respiratory secretion sampling were selected. EB was collected in impermeable bags and EBC was condensed at 70°C, prior to endoscopic recording of tracheal mucus scores(TMS) and TA/BAL fluid sampling. eNO and eCO were measured offline via chemiluminescence; EBC pH was measured using a standardised pH electrode. Associations between exhaled biomarkers and TA/BAL cytological parameters were investigated via regression analysis and 1-ANOVA where appropriate. 25 horses were sampled. A significant association between eCO and TMS was observed (P = 0.019), with horses recording a TMS of 2 or above having significantly higher eCO compared to those with a TMS of 0 or 1 (P = 0.0476). eNO was detectable in only 16% of samples. Horses with neutrophilic LAI were found to have a significantly higher EBC pH (5.83 0.52) compared to those without(5.06 0.63; P = 0.01). The identification of associations between exhaled biomarkers and established markers of LAI provide support for the application of EB and EBC analysis as non-invasive modalities in the investigation of LAI in Thoroughbred horses. Increasing sample size and inclusion of a control group will be required to provide quantitative and qualitative evaluation of these assays.
    Original languageEnglish
    Number of pages1
    Publication statusPublished - 2017
    EventEuropean College of Equine Internal Medicine Congress 2016 (ECEIM 2016) - University of Helsinki, Helsinki, Finland
    Duration: 03 Nov 201605 Nov 2016


    ConferenceEuropean College of Equine Internal Medicine Congress 2016 (ECEIM 2016)
    Internet address


    Dive into the research topics of 'Exhaled carbon monoxide as a marker for lower airway inflammation in thoroughbred racehorses'. Together they form a unique fingerprint.

    Cite this