Effects of an external nasal strip and frusemide on pulmonary haemorrhage in Thoroughbreds following high-intensity exercise.
Authors: Geor R J, Ommundson L, Fenton G, Pagan J D
Journal: Equine veterinary journal
Summary
Exercise-induced pulmonary haemorrhage (EIPH) remains a significant concern in high-performance Thoroughbreds, and this 2001 investigation compared two distinct interventions—an external nasal strip and frusemide administration—to determine their effectiveness in reducing bleeding severity during maximal exertion. Eight horses underwent four randomised treadmill sprint trials (2 minutes at 120% VO₂max on a 3-degree incline) under different treatment conditions: nasal strip only, frusemide alone (0.5 mg/kg intravenously 4 hours pre-exercise), combined treatment, and control. Red blood cell counts in bronchoalveolar lavage fluid served as the primary measure of haemorrhage, collected 30 minutes post-exercise, whilst oxygen consumption and plasma lactate were monitored during effort. Both the nasal strip and frusemide substantially reduced EIPH compared to untreated controls (61.1 × 10⁶ RBC/ml dropping to 15.9 and 12.2 × 10⁶ RBC/ml respectively), with combined treatment producing the most pronounced effect at 7.9 × 10⁶ RBC/ml; notably, the nasal strip lowered the metabolic cost of supramaximal exercise without lactate accumulation differences. For practitioners managing horses prone to EIPH, this evidence suggests the external nasal strip represents a legitimate non-pharmacological alternative to frusemide, particularly valuable given regulatory restrictions on diuretic use in competition, though the additive benefit of combination therapy warrants consideration in severe cases.
Read the full abstract on PubMed
Practical Takeaways
- •External nasal strips offer a non-pharmacological alternative to frusemide for reducing EIPH in racehorses, with potential appeal to racing jurisdictions with stricter medication rules
- •Nasal strips appear to reduce the metabolic cost of high-intensity exercise, suggesting ergogenic benefits beyond hemorrhage reduction
- •Consider nasal strip use as a first-line intervention for EIPH-affected horses, potentially combined with frusemide for cases refractory to single-agent therapy
Key Findings
- •External nasal strip (NS) reduced pulmonary hemorrhage from 61.1×10⁶ to 15.9×10⁶ RBC/ml BAL fluid compared to control (P<0.05)
- •Frusemide (FR) reduced pulmonary hemorrhage to 12.2×10⁶ RBC/ml, similar efficacy to nasal strip (P<0.05)
- •Combined NS + FR treatment produced further reduction to 7.9×10⁶ RBC/ml, significantly better than NS alone (P<0.05)
- •External nasal strip significantly lowered oxygen consumption (VO₂) and CO₂ production during supramaximal sprint exercise without affecting plasma lactate