Use of inhaled ciclesonide for treatment of moderate asthma in Thoroughbred racehorses.
Authors: Sanz Macarena G, Jellen Georgia, Cody Lauren, Bergsma Jenyka, Cha Mandy, Kogan Clark, Kordas Gordon, Bayly Warwick M, Leguillette Renaud
Journal: Journal of veterinary internal medicine
Summary
# Inhaled Ciclesonide for Moderate Asthma in Racehorses Equine asthma affects performance and welfare in racehorses, yet inhaled corticosteroids have previously been licensed only for severe disease; this randomised, double-blinded, placebo-controlled trial evaluated whether a 10-day course of inhaled ciclesonide could benefit horses with moderate asthma at a working racetrack in Washington state. Twenty-one Thoroughbreds received either ciclesonide or placebo, with researchers measuring clinical signs using established scoring systems (HOARSI and cough during exercise), tracheal appearance via endoscopy, and bronchoalveolar lavage fluid (BALF) cellular composition and inflammatory gene expression on days 0 and 10. Only treated horses showed significant improvements: HOARSI scores decreased substantially (P≤0.001), cough episodes reduced by 2.83 on average (P=0.001), mast cell percentages dropped by 2.68% (P=0.03), and inflammatory cytokine expression (IL-6 and IL-13) fell meaningfully within BAL cells (P=0.002 and P=0.03 respectively). For practitioners, these findings suggest ciclesonide may extend therapeutic value to moderate asthma cases without environmental modification, particularly where mastocytic airway inflammation predominates, though the study's relatively small sample size and lack of data on neutrophilic or eosinophilic phenotypes warrant further investigation before routine protocol expansion.
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Practical Takeaways
- •Inhaled ciclesonide can effectively reduce clinical signs and airway inflammation in racehorses with moderate asthma, offering a practical treatment option beyond current severe asthma indications
- •Measurable improvements in cough and inflammatory markers occur within 10 days of treatment, making this a viable option for managing racing performance issues related to moderate asthma
- •This therapy targets mastocytic inflammation specifically; efficacy in other asthma phenotypes (neutrophilic/eosinophilic) is unproven and may require different therapeutic approaches
Key Findings
- •Inhaled ciclesonide treatment for 10 days significantly reduced HOARSI scores (P=0.002) and cough during exercise (P=0.001) in treated racehorses compared to placebo
- •Treatment decreased mast cell percentage in bronchoalveolar lavage fluid (P=0.02; -2.96%) on Day 10 compared to placebo
- •Treated horses showed reduced gene expression of inflammatory cytokines IL-6 (P=0.002) and IL-13 (P=0.03) in BAL cells over the 10-day period
- •Ciclesonide efficacy was demonstrated in moderate asthma without environmental modification, though effects on neutrophilic or eosinophilic asthma phenotypes remain unclear