• 1.

    Birks EK, Shuler KM, Soma LR, et al.EIPH: postrace endoscopic evaluation of Standardbreds and Thoroughbreds. Equine Vet J Suppl 2002;34:375378.

    • Search Google Scholar
    • Export Citation
  • 2.

    Boden LA, Charles JA, Slocombe RF, et al.Sudden death in racing Thoroughbreds in Victoria, Australia. Equine Vet J 2005;37:269271.

  • 3.

    Hinchcliff KW, Jackson MA, Morley PS, et al.Association between exercise-induced pulmonary hemorrhage and performance in Thoroughbred racehorses. J Am Vet Med Assoc 2005;227:768774.

    • Search Google Scholar
    • Export Citation
  • 4.

    Hinchcliff KW. Exercise-induced pulmonary hemorrhage, in Proceedings. Annu Meet Am Assoc Equine Pract 2005;51:342347.

  • 5.

    Heller B. Run baby run: what every owner, breeder and handicapper should know about Lasix in racehorses. Neenah, Wis: Russell Meerdink, 2002.

    • Search Google Scholar
    • Export Citation
  • 6.

    Gross DK, Morley PS, Hinchcliff KW, et al.Effect of furosemide on performance of Thoroughbreds racing in the United States and Canada. J Am Vet Med Assoc 1999;215:670675.

    • Search Google Scholar
    • Export Citation
  • 7.

    Hinchcliff KW, Jackson MA, Brown JA, et al.Tracheobronchoscopic assessment of exercise-induced pulmonary hemorrhage in horses. Am J Vet Res 2005;66:596598.

    • Search Google Scholar
    • Export Citation
  • 8.

    Brown H, Prescott R. Applied mixed models in medicine. 2nd ed. London: J Wiley, 2006.

  • 9.

    Littell R. SAS for mixed models. 2nd ed. Cary, NC: SAS Institute Inc, 2006.

  • 10.

    Stokes ME, Daves CS, Koch GG. Categorical data analysis using the SAS system. 2nd ed. Cary, NC: SAS Institute Inc, 2000.

  • 11.

    Senn S. Cross-over trials in clinical research. New York: J Wiley, 2002.

  • 12.

    Phillips B. Levels of evidence. Available at: www.cebm.net/index.aspx?o=1025#levels. Accessed May 11, 2009.

  • 13.

    Lester G, Clark C, Rice B, et al.Effect of timing and route of administration of furosemide on pulmonary hemorrhage and pulmonary arterial pressure in exercising Thoroughbred racehorses. Am J Vet Res 1999;60:2228.

    • Search Google Scholar
    • Export Citation
  • 14.

    Olsen SC, Coyne CP, Lowe BS, et al.Influence of furosemide on hemodynamic response during exercise in horses. Am J Vet Res 1992;53:742747.

    • Search Google Scholar
    • Export Citation
  • 15.

    Zawadzkas XA, Sides RH, Bayly WM. Is improved high speed performance following frusemide administration due to diuresis-induced weight loss or reduced severity of exercise-induced pulmonary haemorrhage? Equine Vet J Suppl 2006;36:291293.

    • Search Google Scholar
    • Export Citation
  • 16.

    Bayly WM, Slocombe RF, Schott HC II, et al.Effect of intra-venous administration of furosemide on mass-specific maximal oxygen consumption and breathing mechanics in exercising horses. Am J Vet Res 1999;60:14151422.

    • Search Google Scholar
    • Export Citation
  • 17.

    Hinchcliff KW, McKeever KH. Fluid administration attenuates the haemodynamic effect of frusemide in running horses. Equine Vet J 1998;30:246250.

    • Search Google Scholar
    • Export Citation
  • 18.

    Hinchcliff KW, McKeever KH, Muir WW III, et al.Effect of furosemide and weight carriage on energetic responses of horses to incremental exertion. Am J Vet Res 1993;54:15001504.

    • Search Google Scholar
    • Export Citation
  • 19.

    Geor RJ, Ommundson L, Fenton G, et al.Effects of an external nasal strip and frusemide on pulmonary haemorrhage in Thoroughbreds following exercise. Equine Vet J 2001;33:577584.

    • Search Google Scholar
    • Export Citation
  • 20.

    Pascoe JR, McCabe AE, Franti CE, et al.Efficacy of furosemide in the treatment of exercise-induced pulmonary hemorrhage in Thoroughbred racehorses. Am J Vet Res 1985;46:20002003.

    • Search Google Scholar
    • Export Citation
  • 21.

    Clarke A. Comments on furosemide and exercise-induced pulmonary hemorrhage in horses (lett). Am J Vet Res 1989;50:21832184.

  • 22.

    Chay S, Woods WE, Rowse K, et al.The pharmacology of furosemide in the horse. V. Pharmacokinetics and blood levels of furosemide after intravenous administration. Drug Metab Dispos 1983;11:226231.

    • Search Google Scholar
    • Export Citation
  • 23.

    Broadstone RV, Robinson NE, Gray PR, et al.Effects of furosemide on ponies with recurrent airway obstruction. Pulm Pharmacol 1991;4:203208.

    • Search Google Scholar
    • Export Citation
  • 24.

    Kondo CS, Macchionne M, Nakagawa NK, et al.Effects of intravenous furosemide on mucociliary transport and rheological properties of patients under mechanical ventilation. Crit Care 2002;6:8187.

    • Search Google Scholar
    • Export Citation
  • 25.

    Cunningham EP, Dooley JJ, Splan RK, et al.Microsatellite diversity, pedigree relatedness and the contributions of founder lineages to Thoroughbred horses. Anim Genet 2001;32:360364.

    • Search Google Scholar
    • Export Citation
  • 26.

    O'Sullivan CB, Lumsden JM. Veterinary aspects of training and racing Thoroughbred race horses. In: Hinchcliff KW, Kaneps AJ, Geor RJ, eds. Equine sports medicine and surgery: basic and clinical sciences of the equine athlete. London: WB Saunders Co, 2004;10511073.

    • Search Google Scholar
    • Export Citation

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Efficacy of furosemide for prevention of exercise-induced pulmonary hemorrhage in Thoroughbred racehorses

Kenneth W. Hinchcliff BVSc, PhD, DACVIM1, Paul S. Morley DVM, PhD, DACVIM2, and Alan J. Guthrie BVSc, PhD3
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  • 1 Faculty of Veterinary Science, University of Melbourne, Melbourne, VIC 3030, Australia.
  • | 2 Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523.
  • | 3 Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, Gauteng, Republic of South Africa.

Abstract

Objective—To evaluate the efficacy of furosemide for prevention of exercise-induced pulmonary hemorrhage (EIPH) in Thoroughbred racehorses under typical racing conditions.

Design—Randomized, placebo-controlled, blinded, crossover field trial.

Animals—167 Thoroughbred racehorses.

Procedures—Horses were allocated to race fields of 9 to 16 horses each and raced twice, 1 week apart, with each of the 2 races consisting of the same race field and distance. Each horse received furosemide (500 mg, IV) before one race and a placebo (saline solution) before the other, with the order of treatments randomly determined. Severity of EIPH was scored on a scale from 0 to 4 after each race by means of tracheobronchoscopy. Data were analyzed by means of various methods of multivariable logistic regression.

Results—Horses were substantially more likely to develop EIPH (severity score ≥ 1; odds ratio, 3.3 to 4.4) or moderate to severe EIPH (severity score ≥ 2; odds ratio, 6.9 to 11.0) following administration of saline solution than following administration of furosemide. In addition, 81 of the 120 (67.5%) horses that had EIPH after administration of saline solution had a reduction in EIPH severity score of at least 1 when treated with furosemide.

Conclusions and Clinical Relevance—Results indicated that prerace administration of furosemide decreased the incidence and severity of EIPH in Thoroughbreds racing under typical conditions in South Africa.

Abstract

Objective—To evaluate the efficacy of furosemide for prevention of exercise-induced pulmonary hemorrhage (EIPH) in Thoroughbred racehorses under typical racing conditions.

Design—Randomized, placebo-controlled, blinded, crossover field trial.

Animals—167 Thoroughbred racehorses.

Procedures—Horses were allocated to race fields of 9 to 16 horses each and raced twice, 1 week apart, with each of the 2 races consisting of the same race field and distance. Each horse received furosemide (500 mg, IV) before one race and a placebo (saline solution) before the other, with the order of treatments randomly determined. Severity of EIPH was scored on a scale from 0 to 4 after each race by means of tracheobronchoscopy. Data were analyzed by means of various methods of multivariable logistic regression.

Results—Horses were substantially more likely to develop EIPH (severity score ≥ 1; odds ratio, 3.3 to 4.4) or moderate to severe EIPH (severity score ≥ 2; odds ratio, 6.9 to 11.0) following administration of saline solution than following administration of furosemide. In addition, 81 of the 120 (67.5%) horses that had EIPH after administration of saline solution had a reduction in EIPH severity score of at least 1 when treated with furosemide.

Conclusions and Clinical Relevance—Results indicated that prerace administration of furosemide decreased the incidence and severity of EIPH in Thoroughbreds racing under typical conditions in South Africa.

Contributor Notes

All authors contributed equally to this study.

Supported by the National Horseracing Authority of South Africa, Phumelela Gaming and Leisure (Pty) Ltd, TecMed (Pty) Ltd, Racing South Africa (Pty) Ltd, the Grayson-Jockey Club Research Foundation, the Racing Medication and Testing Consortium, the Thoroughbred Racing Trust of South Africa, and private donors.

The authors thank Graeme Hawkins, Elvarde van Zyl, Eddie Smith, Rob de Kock, Dr. Duncan MacDonnald, Dr. Dale Wheeler, Dr. Cindy Harper, Dr. Melvyn Quan, Dr. John Grewar, Dr. Patrick Page, Dr. Rosie Gerber, Dr. Cynthia Donnellan, Dr. Robin Moore, Dr. Karin Kruger, Stellest de Villiers, Anette Nel, Ilse Vorster, Roehan Sutherland, Taelo Sibi, Dr. Rick Sams, and Dr. Schalk de Kock for technical, logistic, and administrative assistance.

Address correspondence to Dr. Hinchcliff.