Inhalation therapy has the advantage of achieving a high local drug concent
ration directly in the airways while minimizing its serum concentration and
, therefore, systemic effects. Inhaled drugs can be delivered to horses usi
ng mechanical nebulizers and metered-dose and dry-powder inhalers. Corticos
teroids, bronchodilators, and cromones are drugs that have proven effective
for inhalation therapy in horses with heaves.