Efficacy of oral prednisolone and dexamethasone in horses with recurrent airway obstruction in the presence of continuous antigen exposure.

The research article investigates the effectiveness of two sustainably administered drugs, prednisolone and dexamethasone, in mitigating the symptoms of recurrent airway obstruction in horses continually exposed to allergens. It concludes that while both drugs enhance respiratory function, dexamethasone appears to be more efficacious at typical doses.

Research Purpose

• This research aimed to assess the effectiveness of two drugs – prednisolone and dexamethasone – commonly used to treat recurrent airway obstruction (RAO) in horses, specifically during continuous allergen exposure.
• While prednisolone’s efficacy in improving lung function in such circumstances had not been closely examined before this study, there was also little pre-existing evidence regarding the benefits of low-dose oral dexamethasone in the same situation.

Methodology

• The research adopted a randomised crossover design involving seven horses experiencing clinical exacerbations of RAO.
• The horses were given prednisolone (2 mg/kg body weight) and dexamethasone (0.05 mg/kg body weight) orally once a day for seven days.
• Before and after three and seven days of treatment, the maximal difference in transpulmonary pressure (DeltaP(L)), lung resistance (R(L)) and elastance (E(L)) were measured to assess pulmonary function.

Results

• Both prednisolone and dexamethasone were found to significantly enhance pulmonary function in the horses.
• Dexamethasone, however, produced more substantial improvement than prednisolone after three and seven days of treatment.
• After seven days of dexamethasone treatment, DeltaP(L) and R(L) were similar to the measurements taken when the horses were healthy and grazing, while the three lung function parameters remained distinct from pasture values after prednisolone treatment.

Conclusions

• Both corticosteroids showed to improve pulmonary function despite continuous allergen exposure. However, oral dexamethasone at 0.05 mg/kg body weight was more effective than prednisolone at 2 mg/kg body weight in treating RAO.
• This research provided the first-known evidence of prednisolone’s ability to enhance the respiratory function of horses with RAO amidst continuous antigen exposure.
• The study also underscored the usefulness of low-dose oral dexamethasone in reversing airway obstruction under the same circumstances.