Efficacy of nasal strip and furosemide in mitigating EIPH in Thoroughbred horses.

This research explored how nasal strips and furosemide, alone and in combination, can mitigate exercise-induced pulmonary hemorrhage in Thoroughbred horses. The study found that while both methods were successful to a degree, neither eliminated the issue completely, and furosemide was more effective than the nasal strips.

Experiment Details

• The investigation used five Thoroughbreds for a treadmill exercise, designed to imitate conditions of near-maximal effort.
• The horses were run under control (Con), furosemide (Fur), nasal strip (NS), or both (NS + Fur) conditions. The treatments were administered in a randomized order, and each run was repeated every two weeks.
• Furosemide was administered at a dosage of 1 mg/kg intravenously, four hours before running.
• During each run, the horses’ pulmonary arterial (Ppa) and esophageal (Pes) pressures were measured to assess the physiological response of the horses to the exercise and interventions.
• The severity of the pulmonary hemorrhage was evaluated via bronchoalveolar lavage (BAL), a diagnostic tool that involves washout of the bronchoalveolar space, 30 minutes after the run.

Findings

• Furosemide managed to reduce peak Ppa around 7 mmHg in comparison to the control condition, while the nasal strip did not show an effect regarding this point.
• There was no significant difference in maximal Pes swings among all groups in the experiment.
• Nasal strip use led to a significant decrease in exercise-induced pulmonary hemorrhage when compared to the control trial. However, furosemide reduced the occurrence of pulmonary hemorrhage to a greater extent than nasal stripes.
• The combined use of both interventions, furosemide and nasal strip, did not deliver additional benefits in terms of reducing the pulmonary hemorrhage.

Conclusion

• Both interventions, furosemide and nasal strips, succeeded to a certain extent in mitigating exercise-induced pulmonary hemorrhage in Thoroughbred horses. However, neither succeeded in fully eradicating the problem.
• While both treatments worked to some degree, furosemide was shown to be more effective than nasal strips in limiting the severity of the condition.
• Finally, using both interventions at the same time demonstrated no further improvements in reducing the pulmonary hemorrhage, suggesting that their effects may not be cumulative.