Abstract: The purpose of this study was to examine the effects of an external nasal strip (NS), frusemide (FR) and a combination of the 2 treatments (NS + FR) on exercise-induced pulmonary haemorrhage (EIPH) in Thoroughbred horses. It was hypothesised that both the NS and FR would attenuate EIPH as assessed by red blood cell count in bronchoalveolar lavage fluid. In random order, 8 horses completed each of 4 sprint exercise tests on a treadmill: 1) NS; 2) FR (0.5 mg/kg bwt i.v., 4 h pre-exercise); 3) NS + FR; and 4) control (C; no treatment). After a 5 min warm-up (4.5 m/s), horses completed 2 min running at 120% maximum oxygen consumption (VO2max) with the treadmill set at 3 degrees incline. Mean +/- s.d. running speed was 14.2+/-0.2 m/s. In the FR and NS + FR trials, horses carried weight equal to that lost as a result of frusemide administration. During exercise at 120% Vo2max, oxygen consumption (Vo2) and carbon dioxide production (Vco2) were measured at 15 s intervals. Plasma lactate concentration was measured in samples collected before exercise, at the end of the sprint and after 5 min cool-down at the trot. Thirty minutes after the run, bronchoalveolar lavage (BAL) was performed and the red cell count in the fluid quantified. Vo2 and Vco2 were significantly lower in NS and NS + FR trials than in the C and FR trials at the end of the sprint exercise protocol. However, plasma lactate concentrations did not differ among treatments. Compared with the C trial (61.1+/-30.5 x 10(6) red blood cells/ml BAL fluid), pulmonary haemorrhage was significantly (P<0.05) decreased in both the NS (15.9+/-4.0 x 106 RBC/ml) and FR (12.2+/-5.8 x 10(6) RBC/ml) trials. EIPH in the NS + FR trial (7.9+/-1.0 x 10(6) RBC/ml) was further diminished (P<0.05) compared to the NS trial, but not different from the FR trial. We conclude that both the external nasal strip and frusemide attenuate pulmonary haemorrhage in Thoroughbred horses during high-speed sprint exercise. The external nasal strip appears to lower the metabolic cost of supramaximal exertion in horses. Given the purported ergogenic effects of frusemide, the external nasal strip is a valuable alternative for the attenuation of EIPH.
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
This research attempts to determine the impact of two treatments, external nasal strips and frusemide, individually and in combination, on exercise-induced pulmonary haemorrhage in Thoroughbred horses used for high-intensity exercise.
Research Purpose and Hypothesis
The study aims to understand the effect of external nasal strips (NS), frusemide (FR), and the combination of these two treatments on exercise-induced pulmonary haemorrhage (EIPH) in Thoroughbred horses.
The researchers hypothesized that both NS and FR would reduce EIPH, which would be verified by counting the red blood cells in the bronchoalveolar lavage (BAL) fluid of the horses.
Methodology
Eight Thoroughbred horses underwent a set of four sprint exercise tests on a treadmill in random order.
The four tests were differentiated based on the treatment given to the horses – application of NS, intake of FR (0.5 mg/kg bwt, intravenously given 4 hours before exercise), a combination of NS and FR, and control (no treatment).
Observations were made for oxygen consumption, carbon dioxide production, plasma lactate concentration, and red blood cell count in BAL fluid during the exercise trials.
Findings
Measurements of oxygen consumption and carbon dioxide production were lower in the NS and NS+FR trials compared with the control test and the frusemide-only test towards the end of the sprint exercise.
Plasma lactate concentrations, however, did not vary across the different treatments.
Compared to the control trial, pulmonary haemorrhage significantly decreased in the NS and FR trials, as evident through the red blood cell count in the BAL fluid.
The combination of NS and FR showed a further decrease in pulmonary haemorrhage compared to the NS-only trial, although this was not significantly different from the FR-only trial.
Conclusion
The researchers concluded that both NS and FR successfully reduce pulmonary haemorrhage in Thoroughbred horses subjected to high-intensity exercise.
The theory that NS can lower the metabolic cost of high-intensity effort in horses has been supported by this study.
Considering the ergogenic effects of frusemide, NS is regarded as a viable alternative for alleviating exercise-induced pulmonary haemorrhage in Thoroughbred horses.
Cite This Article
APA
Geor RJ, Ommundson L, Fenton G, Pagan JD.
(2001).
Effects of an external nasal strip and frusemide on pulmonary haemorrhage in Thoroughbreds following high-intensity exercise.
Equine Vet J, 33(6), 577-584.
https://doi.org/10.2746/042516401776563490
Kentucky Equine Research, Inc., Versailles 40383, USA.
Ommundson, L
Fenton, G
Pagan, J D
MeSH Terms
Animals
Body Weight / drug effects
Bronchoalveolar Lavage Fluid / cytology
Carbon Dioxide / metabolism
Combined Modality Therapy
Diuretics / pharmacology
Diuretics / therapeutic use
Erythrocyte Count / veterinary
Exercise Test / veterinary
Female
Furosemide / pharmacology
Furosemide / therapeutic use
Hemorrhage / prevention & control
Hemorrhage / veterinary
Horse Diseases / prevention & control
Horses
Lactates / blood
Lung Diseases / prevention & control
Lung Diseases / veterinary
Male
Oxygen Consumption / drug effects
Physical Conditioning, Animal / adverse effects
Pulmonary Gas Exchange / drug effects
Random Allocation
Time Factors
Citations
This article has been cited 6 times.
Poole DC, Copp SW, Colburn TD, Craig JC, Allen DL, Sturek M, O'Leary DS, Zucker IH, Musch TI. Guidelines for animal exercise and training protocols for cardiovascular studies. Am J Physiol Heart Circ Physiol 2020 May 1;318(5):H1100-H1138.