2015 ACVIM Forum Research Abstract Program

Compared to other organ systems, the respiratory tract harbors a more homogenous and less rich microbiota that decreases in richness but varies little in community structure from upper to lower airways. This study establishes baseline data for the healthy equine airway microbiota. Human studies have previously documented a strong association between vitamin D deficiency and bronchial asthma, a condition similar to equine inflammatory airway disease (IAD). The goal of this study was, therefore, to evaluate the relationship between serum 25-Hydroxyvitamin-D levels and IAD in horses. Twenty-three horses fulfilling the diagnostic criteria of IAD, as previously defined (2007 ACVIM consensus), were recruited for this study. Additionally, 13 asymptomatic control animals were sampled from comparable stabling environments. Serum 25-Hydroxyvitamin-D analysis (nmol/L), broncho-alveolar-lavage fluid (BALF) cytology and non-invasive pulmonary function testing (forced oscillatory mechanics -FOM, or respiratory inductive plethysmography -RIP) for the assessment of airway hyperreactivity (AHR) were performed in all horses. BALF slides were stained with modified Wright stain and Toluidine Blue. All data were presented descriptively as mean (AE standard deviation) based on normality of data distribution. Categorical data were compared between groups using Chi-square analysis, and continuous variables using independent samples t-test, with P < 0.05 considered significant.