Drugs Acting on the Respiratory System and Inhalation Therapy

Equine respiratory disorders – including infectious diseases and asthma – significantly impact horse health and performance and pose major challenges for clinicians. To address these issues, aerosol therapy serves as a cornerstone of care, enabling targeted drug delivery with rapid onset and fewer systemic side effects. Therapeutic success depends on particle size, inhalation dynamics, and airway obstruction, which influence drug distribution within the lungs. Advances in nebulization technology and aerosol formulations have improved efficacy, yet challenges remain with device optimization, patient compliance, and achieving uniform pulmonary deposition. Delivery devices – nebulizers, pressurized metered-dose inhalers, and soft mist inhalers – are compared for ease of use, deposition efficiency, and practicality. Pharmacokinetic principles and therapies, including bronchodilators, anti-inflammatories, mucolytics, and antimicrobial nebulization, are reviewed with attention to clinical applications, safety, and limitations. Future research should refine delivery systems, improve formulation stability, and develop novel agents to enhance outcomes in equine respiratory medicine.