Data
A cross-sectional study was performed including 604 BAL samples, from clinical cases, submitted by referring veterinarians all over Denmark during the period between 2016-2019, to the diagnostic service at the University of Copenhagen. A questionnaire and further information were provided from both the horse owner and referring veterinarian about the horse, clinical symptoms and BAL procedure. Duplicate samples were excluded from the analysis. Furthermore, data were excluded if another BAL volume than 200-250 ml was used, if shipping had been delayed or if the sample was of a non-diagnostic quality.