Equine Recurrent Airway Obstruction

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Equine Recurrent Airway Obstruction (RAO), also known as heaves or broken wind, is one of the most common disease in middle-aged horses. Inflammation of the airway is inducted by organic dust exposure. This disease is characterized by neutrophilic inflammation, bronchospasm, excessive mucus production and pathologic changes in the bronchiolar walls. Clinical signs are resolved in 3-4 weeks after environmental changes. Horses suffering from RAO are susceptible to allergens throughout their lives, therefore they should be properly managed. In therapy the most importanthing is to eliminate dust exposure, administration of corticosteroids and use bronchodilators to improve pulmonary function.

Keywords: RAO; horses; heaves


  • 1. Davis, E., Rush B.R. (2002). Equine recurrent airway obstruction: pathogenesis, diagnosis and patient management. Vet Clin North Am Equine Pract, 18: 453-467. http://dx.doi.org/10.1016/S0749-0739(02)00026-3 PMid:12516928

  • 2. Halliwell, R.E., McGorum, B.C., Irving, P., Dixon, P.M. (1993). Local and systemic antibody production in horses affected with chronic obstructive pulmonary disease. Vet Immunol Immunopathol, 38: 201-215. PMid: 8291200

  • 3. Bureau, F., Bonizzi, G., Kirschvink, N. (2000). Correlation between nuclear factor-kB activity in bronchial brushing samples and lung dysfunction in an animal model of asthma. Am J Respir Crit Care Med, 161: 1314-1321. http://dx.doi.org/10.1164/ajrccm.161.4.9907010 PMid:10764329

  • 4. Lavoie, J.P., Maghni, K., Desnoyers, M., Taha, R., Martin, J.G., Hamid, Q.A. (2001). Neutrophilic airway inflammation in horses with heaves is characterized by a Th2-type cytokine profile. Am J Respir Crit Care Med. 164: 1410-1413. http://dx.doi.org/10.1164/ajrccm.164.8.2012091 PMid:11704587

  • 5. Léguillette R. (2003). Recurrent airway obstructionheaves. Vet Clin North Am Equine Pract, 1: 63-86. PMid:12747662

  • 6. Fernandez, N.J., Hecker, K.G., Gilroy, C.V., Warren, A.L., Léguillette, R. (2013). Reliability of 400-cell and 5-field leukocyte differential counts for equine bronchoalveolar lavage fluid. Vet Clin Pathol, 1: 92-98. http://dx.doi.org/10.1111/vcp.12013 PMid:23289790

  • 7. Dixon, P.M., Railton, D.I., McGorum, BC. (1995). Equine pulmonary disease: a case control study of 300 referred cases: part 3. Ancillary diagnostics findings. Equine Vet J, 27: 428-435. http://dx.doi.org/10.1111/j.2042-3306.1995.tb04423.x PMid:8565939

  • 8. Leclere, M., Lavoie-Lamoureux, A., Lavoie, J.P. (2011). Heaves, an asthma-like disease of horses. Respirology, 7: 1027-1046. http://dx.doi.org/10.1111/j.1440-1843.2011.02033.x PMid:21824219

  • 9. Thomson J.R., McPherson E.A. (1983). Chronic obstructive pulmonary disease in the horse. Part 2: Therapy. Equine Vet J, 15: 207-210. http://dx.doi.org/10.1111/j.2042-3306.1983.tb01766.x PMid:6411459

  • 10. Thomson J.R., McPherson E.A. (1984). Effects of environmental control on pulmonary function of horses affected with chronic obstructive pulmonary disease. Equine Vet J, 16: 35-38. http://dx.doi.org/10.1111/j.2042-3306.1984.tb01845.x PMid:6714203

  • 11. Woods, P.S., Robinson, N.E., Swanson, M.C., Reed C.E., Broadstone, R.V., Derksen, F.J. (1993). Airborne dust and aeroallergen concentration in a horse stable under two different management systems. Equine Vet J, 25: 208-213. http://dx.doi.org/10.1111/j.2042-3306.1993.tb02945.x PMid:8508749

  • 12. McGorum, B.C., Dixon, P.M., Halliwell, R.E.W. (1993). Response of horses affected with chronic obstructive pulmonary disease to inhalation challenge with mould antigens. Equine Vet J, 25: 261-267. http://dx.doi.org/10.1111/j.2042-3306.1993.tb02960.x PMid:8354208

  • 13. Jackson, C.A., Berney, C., Jefcoat, A.M., Robinson, N.E. (2000). Environment and prednisone interactions in the treatment of recurrent airway obstruction (heaves). Equine Vet J, 5: 432-438.

  • 14. Lavoie, J.P. (2001). Update on equine therapeutics: inhalation therapy for equine heaves. Compend Contin Educ Pract Vet, 23: 475-477.

  • 15. Robinson, N.E., Jackson, C., Jefcoat, A., Berney, C., Peroni, D., Derksen, F.J. (2002). Efficacy of three corticosteroids for the treatment of recurrent airway obstruction (heaves). Equine Vet J, 34: 17-22. http://dx.doi.org/10.2746/042516402776181105 PMid:11817547

  • 16. Robinson, N.E., Berney, C., Eberhart, S., deFeijter- Rupp, H.L., Jefcoat, A.M., Cornelisse, C.J., Gerber, V.M., Derksen, F.J. (2003). Coughing, mucus accumulation, airway obstruction, and airway inflammation in control horses and horses affected with recurrent airway obstruction. Am J Vet Res, 64: 550-557. http://dx.doi.org/10.2460/ajvr.2003.64.550 PMid:12755293

  • 17. Tilley, P., Sales Luis, J.P., Branco Ferreira, M. (2012). Correlation and discriminant analysis between clinical, endoscopic, thoracic X-ray and bronchoalveolar lavage fluid cytology scores, for staging horses with recurrent airway obstruction (RAO). Res Vet Sci, 93:1006-1014. http://dx.doi.org/10.1016/j.rvsc.2011.10.024 PMid:22136797

Macedonian Veterinary Review

The Journal of the Faculty of Veterinary Medicine-Skopje at the Ss. Cyril and Methodius University in Skopje

Journal Information

CiteScore 2016: 0.28

SCImago Journal Rank (SJR) 2016: 0.161
Source Normalized Impact per Paper (SNIP) 2016: 0.368


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