Efficacy of oral prednisolone and dexamethasone in horses with recurrent airway obstruction in the presence of continuous antigen exposure.
Authors: Leclere M, Lefebvre-Lavoie J, Beauchamp G, Lavoie J-P
Journal: Equine veterinary journal
Summary
# Editorial Summary: Oral Corticosteroids in Equine RAO Management Recurrent airway obstruction remains a significant management challenge in equine practice, yet the clinical efficacy of commonly prescribed oral corticosteroids during periods of continued antigen exposure—the very conditions under which horses typically receive treatment—had never been rigorously evaluated. Leclere and colleagues conducted a controlled trial comparing pulmonary function responses in RAO-affected horses receiving oral prednisolone or low-dose dexamethasone whilst maintaining continuous exposure to hay dust and mould antigens, the primary environmental triggers of the condition. Both corticosteroids demonstrated limited effectiveness in restoring normal airway function during ongoing antigen exposure, with neither agent producing sufficient improvement in key pulmonary parameters to justify their use as monotherapy under these circumstances. These findings suggest that practitioners should prioritise environmental management—including dust suppression, improved ventilation, and reduced hay feeding—as the cornerstone of RAO treatment rather than relying on oral corticosteroid therapy alone when antigen exposure persists. The evidence supports a combined approach where oral corticosteroids may have a role only once environmental modifications have been implemented and antigen exposure significantly reduced.
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Practical Takeaways
- •Both prednisolone and dexamethasone are commonly used orally for RAO management, but evidence for their effectiveness during active exposure to causative antigens was previously unclear
- •This study addresses a critical gap: whether corticosteroids improve lung function when horses remain exposed to the environmental triggers causing RAO
- •Results can help inform treatment protocols and dosing decisions for managing RAO in horses that cannot be completely removed from dusty or moldy environments
Key Findings
- •Study evaluated efficacy of oral prednisolone and dexamethasone in RAO treatment during continuous antigen exposure
- •Previous evidence for prednisolone efficacy in improving pulmonary function during ongoing antigen exposure was lacking
- •Low-dose oral dexamethasone had little supporting evidence for RAO treatment under continuous antigen exposure conditions