Equine asthma is a disease with a significant negative impact on horse welfare and performance. Novel biomarkers for the disease have the potential to support diagnosis and prediction of treatment response. In a previous study we discovered genes that were significantly upregulated in lung immune-cells of horses diagnosed with asthma. In this study we aim to evaluate if these novel candidates can be used as reliable biomarkers for equine asthma. Moreover, we will examine the feasibility of detecting equine asthma biomarkers by a simple blood sample.