On Nasal Strips (and tongue ties) in racehorses....
Yesterday afternoon, California Chrome trainer Art Sherman contacted the NYRA Stewards requesting permission to use nasal strips on the horse. In a Stewards house rule, nasal strips had previously fallen under the broad catch-all of a non approved device and was thus banned from use in NY where is it not as popular as it is in say California where just about every trainer is using them. The Stewards immediately sought comment from New York State Gaming Commission Equine Medical Director Scott E. Palmer, VDM, on the use. Dr. Palmer wrote:
"I recommend that the stewards at State-based Thoroughbred racetracks discontinue their ban on equine nasal strips. Equine nasal strips do not enhance equine performance nor do they pose a risk to equine health or safety and as such do not need to be regulated.
While there is research to indicate that equine nasal strips decrease airway resistance in horses and may decrease the amount of bleeding associated with EIPH to some degree, I am unfamiliar with any research indicating that equine nasal strips enable a horse to run faster with nasal strips than without them. In other words, there is no evidence they have a performance enhancing effect. Equine nasal strips do not pose a welfare or safety risk to the horse. They are applied to the top of the nose and anyone can see their use prior to a race. If improperly applied, equine nasal strips cannot interfere with performance. In my opinion equine nasal strips fall into the same category as tongue-ties."
The Stewards considered Dr. Palmer's advice and thus determined to allow the unregulated use of the nasal strips.
So where does the science that Dr Palmer refers to fall on this. For ease of understanding we can look at the studies in chronological order and I have linked the reports so if you click on the title you can see the abstract.
2000 - Poole, et al "Effects of external nasal support on pulmonary gas exchange and EIPH in the horse". Their findings were that nasal dilation can lower whole body V̇O2 and reduce EIPH. It is possible that these effects are secondary to a decreased inspiratory resistance, lowered inspiratory muscle work and altered intrapulmonary pressures.
2001 - Goetz, et al "Nasal strips do not affect pulmonary gas exchange, anaerobic metabolism, or EIPH in exercising Thoroughbreds". Their findings were that application of an external nasal dilator strip neither improved the exercise-induced arterial hypoxemia and hypercapnia nor diminished anaerobic metabolism or the incidence of EIPH in Thoroughbred horses performing strenuous exercise.
2001 - Goer, et al "Effects of an external nasal strip and frusemide on pulmonary haemorrhage in Thoroughbreds following high-intensity exercise". Their findings were that both the external nasal strip and frusemide(Lasix) 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.
2001 - Kindig, et al "Efficacy of nasal strip and furosemide in mitigating EIPH in Thoroughbred horses". Their findings were that although both modalities (Nasal Strip and Frusemide) were successful in mitigating EIPH, neither abolished EIPH fully as evaluated via BAL. Frusemide was more effective than Nasal Strip in constraining the severity of EIPH. The simultaneous use of both interventions appears to offer no further gain with respect to reducing EIPH.
2002 - Holcolme, et al "Effect of commercially available nasal strips on airway resistance in exercising horses". Their findings were that the commercially available nasal strip tented the skin over the nasal valve and dilated that section of the nasal passage, resulting in decreased airway resistance during inspiration. The nasal strip probably decreases the amount of work required for respiratory muscles in horses during intense exercise and may reduce the energy required for breathing in these horses.
2004 - McDonough, et al, "Effect of furosemide and the equine nasal strip on exercise-induced pulmonary haemorrhage and time-to-fatigue in maximally exercising horses". Their findings were that both frusemide and nasal strip enhance Time to Fatigue and reduce EIPH to a similar degree during high-speed treadmill running to fatigue.
2004 - Valdez, et al "Effect of an external nasal dilator strip on cytologic characteristics of bronchoalveolar lavage fluid in Thoroughbred racehorses". Their finding was that use of an external nasal dilator strip in Thoroughbred racehorses may decrease pulmonary bleeding, particularly in horses with severe exercise induced pulmonary hemorrhage.
So in summary, Goetz, et al found no effect of nasal strips on thoroughbreds where the other six studies found that nasal strips had some effect in either reducing bleeding or a decrease in effort required to breath using the strips.
It's interesting that Palmer specifically said that he was "unfamiliar with any research indicating that equine nasal strips enable a horse to run faster with nasal strips than without them". The term "enhanced" is a rather grey area in this case as they don't "run faster" per se, that is their maximal velocity isn't any higher, they just fatigue slower. McDonough, et al's paper was fairly unequivocal in its summary that the use of Lasix and the Nasal strip enhanced "Time to Fatigue", that is it took longer for horses using the nasal strip and Lasix to fatigue than the control group without these. If you are a trainer, you'd want to be using both, especially in distance races.
It's also interesting that Palmer has classified the nasal strip as falling into the same category as "tongue-ties". In 2009 Barakzai, et al showed that the use of a tongue tie had a measurable effect on performance. However, it is most likely that the application of the tongue tie was done on horses with palatial instability in the first place. The science isn't quite clear if a tongue tie on a clinically normal horse has an effect. Cornelisse, et al who back in 2001 found that the application of a tongue-tie did not alter upper respiratory mechanics in exercising horses and does not improve upper airway mechanics in clinically normal horses but late last year Chalmers, et al in their paper "The use of a tongue tie alters laryngohyoid position in the standing horse" found that the tongue tie had a measurable effect on upper airway structure in the standing horse but that the functional implications of their finding was yet to be elucidated. Should Chalmers et al find that a tongue tie does have a measurable performance effect on clinically normal horses start to see it become the norm also.