Veterinary Research Communications

, Volume 19, Issue 6, pp 517–527 | Cite as

The effects of three models of airway disease on tidal breathing flow-volume loops of thoroughbred horses

  • A. J. Guthrie
  • R. E. Beadle
  • R. D. Bateman
  • C. E. White


The effects of histamine and methacholine aerosols and of a fixed inspiratory resistance on tidal breathing flow-volume loops (TBFVL) were investigated using 18 unsedated, standing, healthy thoroughbred horses. The data were first analysed using traditional flow-volume loop indices and then reduced using standardized factor scoring coefficients obtained in a previous study in this laboratory using similar experimental techniques. On the basis of resting TBFVL analysis, the degree of pulmonary dysfunction caused by inhalation of histamine and methacholine aerosols with concentrations of 10 and 2 mg/ml, respectively, was similar. The fixed resistance also caused significant changes in the resting spirogram and TBFVL indices, suggesting that this model may prove valuable for further studies involving upper respiratory tract (URT) conditions.

Administration of histamine and methacholine aerosols resulted in significant changes in all factor scores, although most of the observed changes were due to the effects of these aerosols on the respiratory rate. These findings re-emphasize the importance of the effects of respiratory rate on pulmonary mechanics. Application of the resistance resulted in significant changes in factor score 3, the ‘inspiratory’ factor, which lends support to the validity of this model for URT conditions. The close agreement between the factor scores obtained under controlled conditions in this study and in a previous study in this laboratory confirms that the factor analysis used for both of these studies provides an adequate means of reducing TBFVL data obtained from thoroughbred horses.

The large intra- and inter-individual variation observed both with the indices of TBFVL and with the factor scores limits the potential of these variables for detecting individual animals with obstructive airway disease. Re-evaluation of these indices under the stress of exercise may reduce the variability observed in these data and may increase the magnitude of differences between different animals, providing a means of detecting individual animals with subclinical obstructive airway conditions.


factor analysis flow-volume loop histamine horse inspiratory resistance methacholine pulmonary function 



coefficient of variation


maximal intrapleural pressure difference


flow-volume loop


lower respiratory tract


airway opening pressure


transpulmonary pressure


tidal breathing flow-volume loop


upper respiratory tract


ultrasonic pneumotachometer


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Abramson, A.L., Goldstein, M.N. and Stenzler, A., 1982. The use of the tidal breathing flow-volume loop in laryngotracheal disease of neonates and infants.Laryngoscope,92, 922–926PubMedGoogle Scholar
  2. Amis, T.C. and Kurpershoek, C., 1986a. Pattern of breathing in brachycephalic dogs.American Journal of Veterinary Research,47, 2200–2204PubMedGoogle Scholar
  3. Amis, T.C. and Kurpershoek, C., 1986b. Tidal breathing flow-volume loop analysis for clinical assessment of airway obstruction in conscious dogs.American Journal of Veterinary Research,47, 1002–1006PubMedGoogle Scholar
  4. Amis, T.C., Smith, M.M., Gaber, C.E. and Kurpershoek, C., 1986. Upper airway obstruction in canine laryngeal paralysis.American Journal of Veterinary Research,47, 1007–1010PubMedGoogle Scholar
  5. Art, T. and Lekeux, P., 1988. Respiratory airflow patterns in ponies at rest and during exercise.Canadian Journal of Veterinary Research,52, 299–303PubMedGoogle Scholar
  6. Beadle, R.E., Guthrie, A.J. and Kou, A.H., 1995. Characterization of a density-corrected ultrasonic pneumotachometer for horses.Journal of Applied Physiology,78, 359–367PubMedGoogle Scholar
  7. Butler, J.P., Leith, D.E. and Jackson, A.C., 1986. Principles of measurement: applications to pressure, volume, and flow. In: A.P. Fishman (ed.),Handbook of Physiology. The Respiratory System III, (American Physiological Society, Bethesda), 15–33Google Scholar
  8. Connally, B.A. and Derksen, F.J., 1994. Tidal breathing flow-volume loop analysis as a test of pulmonary function in exercising horses.American Journal of Veterinary Research,55, 589–594PubMedGoogle Scholar
  9. Derksen, F.J., Robinson, N.E., Slocombe, R.F., Riebold, T.W. and Brunson, D.B., 1982. Pulmonary function tests in standing ponies: reproducibility and effect of vagal blockade.American Journal of Veterinary Research,43, 598–602PubMedGoogle Scholar
  10. Duncan, I.D., 1987. Some aspects of the neuropathy of equine laryngeal hemiplagia.Proceedings of the American College of Veterinary Internal Medicine,5, 863–865Google Scholar
  11. Gillespie, J.R., 1974. The role of the respiratory system during exertion.Journal of the South African Veterinary Association,45, 305–309Google Scholar
  12. Gillespie, J.R., Tyler, W.S. and Eberly, V.E., 1966. Pulmonary ventilation and resistance in emphysematous and control horses.Journal of Applied Physiology,21, 416–422PubMedGoogle Scholar
  13. Guthrie, A.J., 1990.Evaluation of selected pulmonary function tests in resting thoroughbred horses having reversible, experimentally induced respiratory dysfunctions, (PhD dissertation, Louisiana State University, Baton Rouge)Google Scholar
  14. Guthrie, A.J., Beadle, R.E., Bateman, R.D. and White, C.E., 1992. Temporal effects of inhaled histamine and methacholine aerosols on pulmonary mechanics of thoroughbred horses.Journal of Veterinary Pharmacology and Therapeutics,15, 317–331PubMedGoogle Scholar
  15. Guthrie, A.J., Beadle, R.E., Bateman, R.D. and White, C.E., 1995. Characterization of normal tidal breathing flow-volume loops for thoroughbred horses.Veterinary Research Communications,19, in pressGoogle Scholar
  16. Jackson, A.C. and Vinegar, A., 1979. A technique for measuring frequency response of pressure, volume, and flow transducers.Journal of Applied Physiology,47, 462–467PubMedGoogle Scholar
  17. Johnson, R.A. and Wichern, D.W., 1988.Applied Multivariate Statistical Analysis, 2nd edn, (Prentice-Hall, Englewood Cliffs)Google Scholar
  18. Lumsden, J.M., Derksen, F.J., Stick, J.A. and Robinson, N.E., 1993. Use of flow-volume loops to evaluate upper airway obstruction in exercising standardbreds.American Journal of Veterinary Research,54, 766–775PubMedGoogle Scholar
  19. Mason, D.K., Collins, E.A. and Watkins, K.L., 1983. Exercise induced pulmonary haemorrhage in horses. In: D.H. Snow, S.G.B. Persson and R.J. Rose (eds),Equine Exercise Physiology, (Granta Editions, Cambridge), 57–63Google Scholar
  20. Pascoe, J.R. and Wheat, J.D., 1981. Historical background, prevalence, clinical findings and diagnosis of exercise-induced pulmonary hemorrhage (EIPH) in the racing horse.Proceedings of the Annual Convention of the American Association of Equine Practitioners,26, 417–420Google Scholar
  21. Petsche, V.M., Derksen, F.J. and Robinson, N.E., 1994. Tidal breathing flow-volume loops in horses with recurrent airway obstruction (heaves).American Journal of Veterinary Research,55, 885–891PubMedGoogle Scholar
  22. Raphel, C.F. and Soma, L.R., 1982. Exercise-induced pulmonary hemorrhage in thoroughbreds after racing and breezing.American Journal of Veterinary Research,43, 1123–1131PubMedGoogle Scholar
  23. Robinson, N.E. and Derksen, F.J., 1981. Small airway obstruction as a cause of exercise-associated pulmonary hemorrhage: an hypothesis.Proceedings of the Annual Convention of the American Association of Equine Practitioners,26, 421–430Google Scholar
  24. SAS Institute Inc., 1988.SAS/STAT User's Guide, Release 6.03 Edition, (SAS Institute Inc., Cary, NC)Google Scholar
  25. Stadler, P. and Deegen, E., 1986. Diurnal variation of dynamic compliance, resistance and viscous work of breathing in normal horses and horses with lung disorders.Equine Veterinary Journal,18, 171–178PubMedGoogle Scholar
  26. Steel, R.G.D. and Torrie, J.H., 1980.Principles and Procedures of Statistics: A Biometrical Approach, 2nd edn, (McGraw-Hill, New York)Google Scholar
  27. Takishima, T., Grimby, G., Graham, W., Knudson, R., Macklem, P.T. and Mead, J., 1967. Flow-volume curves during quiet breathing, maximum voluntary ventilation, and forced vital capacities in patients with obstructive disease.Scandinavian Journal of Respiratory Diseases,48, 384–393PubMedGoogle Scholar

Copyright information

© Kluwer Academic Publishers bv 1995

Authors and Affiliations

  • A. J. Guthrie
    • 1
  • R. E. Beadle
    • 2
  • R. D. Bateman
    • 2
  • C. E. White
    • 2
  1. 1.Department of Veterinary Physiology, Pharmacology and ToxicologyLouisiana State UniversityBaton RougeUSA
  2. 2.Department of Veterinary Clinical Sciences, School of Veterinary MedicineLouisiana State UniversityBaton RougeUSA

Personalised recommendations