Case definition
Based on the previous consensus statement,1 a
diagnosis of mild-moderate asthma (MA) was made based on the presence of
clinical signs (poor performance, chronic occasional coughing, or both),
evidence of airway inflammation in BALF cytology, presence of
significant amount of tracheal mucus detected by endoscopy (grade
> 2/5), and the exclusion of severe asthma (SA) based on
history and clinical signs. For BALF cytology, the ‘less restrictive’
cut-off was used: neutrophils > 10%, mast cells
> 5% and eosinophils > 5% in individual
(left and right) BALF,1,19 and neutrophils
> 9%, mast cells > 3% and eosinophils
> 3% in pooled BALF.20 A diagnosis of SA
was made based on history, presence of increased respiratory effort at
rest, and moderate to severe neutrophilia in BALF (> 25%)
in horses of middle to advanced age (> 7 years
old).1 Horses without coughing, nasal discharge, or
increased respiratory effort, with normal BALF cytology from both lungs,
and with a negative bacterial culture from TW were classified as
controls (CTL). Cytology was classified as positive when at least one
fungal element (spore, hyphae) was observed on the slide (TW, individual
or pooled BALF). Fungal culture was classified as positive when one or
more colonies were observed (and identified) in a sample (TW or pooled
BALF).