Education Articles
Respiratory System | Fatigue | EIPH
Respiratory System
Quick respiratory faces from Dr. David Marlin:
- Cross-country is 90% aerobic
- A horse uses two buckets of oxygen every second while galloping.
- The skin over the nasal passages is sucked in every time the horse takes a breath and obstructs the nasal passage.
- Hyperflexion can also obstruct the airway.
Dr. David Marlin, The Roars & Gurgles, Wheezes & Coughs, seminar given at the USEA Convention, December 2009.
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Horses hold their breath over fences, and breathe in rhythm with their strides. These scientific facts are critical to understanding how to help performance horses compete at their best. On a typical show jumping course of 18 jumping efforts performed in 60 seconds, a horse may hold its breath for up to one-third of that time. And since a horse’s breathing is directly linked to their stride, riding a course of fences in a consistent stride reduces physical stress on the horse. Detailed illustrations show exactly when a horse holds its breath during a jumping effort, and the phases of breathing and striding.
Dr. David Marlin, Breathing, Stride, and Jumping Performance, The Horse, May 2009 Read More
Perhaps in no other sport is a horse’s stride so critical as show jumping. Distances between fences are measured exactly and are based upon a horse’s stride length. Success in the jumper ring depends on the horse and rider getting the stride length correct. Jumping too early, or too late, may result in a knock-down and keep the competitor out of the ribbons and money. This article discusses how breathing and strides are interdependent, and how important it is that the performance horse be able to breathe without compromise.
Dr. David Marlin, Veterinary clinic: Breathing, stride and could they be linked? Horse & Hound, March, 19, 2009 Read More
The horse’s upper airway provides a high resistance to airflow into the lungs and may be a limiting factor in the horse’s exercise capacity. Strong evidence suggests that upper airway resistance limits arterial blood oxygenation in exercising horses therby limiting oxygen delivery to tissues and performance. In the exercising horse, during inhalation, the upper airway is responsible for over 75% of the total resistance to airflow into the lungs. 50% of total airway resistance, upper (nostrils, nasal passages, throat) and lower (trachea, lungs) comes from the nasal passages. Read more
This Fact Sheet was provided by The Horse for educational purposes provides useful information on the structure, function and some problems that can occur in the upper airway. Please visit www.TheHorse.com for other Fact Sheets.
By the time a horse crosses the finish line in a five-mile race, has completed a Grand Prix show jumping round, or gone one-sixth of the way rough a three-star cross-country course, he will have moved somewhere around 1,800 liters of air in and out of the lungs. If you find 1,800 liters hard to visualize, then think of six bathtubs full of air. This equates to moving two five-gallon buckets of air into and out of the lung every second.
Dr. David Marlin, The Airways and The Lungs, The Horse, November 2007 Read More
Exercise, whether in training or in competition, places tremendous demands on many of the different body systems of the horse. Exercise makes the respiratory sys- tem move more oxygen-rich air in and out of the lungs to replenish the blood oxygen concentration, the heart works harder to pump more oxygen rich blood to the muscles, the muscles contract around twice each second (to achieve stride rates of around 120 strides/minute) to propel the horse and the skeleton and other soft tissues must support the whole weight of the horse’s body as it moves.
Dr. David Marlin, The Growing Physical Demands of Modern Equestrian Sport, Eventing USA, Issue 2, 2008 Read More
The difference between being very good and being world class is the smallest of margins. Competitively only a very few make that final toughest push, to take them onto the world class stage. The basic ingredients all have to be in place to be a contender, natural talent, commitment and, in the equine world, the right horses. Twenty-year old International show jumper, Ryan Prater, has proved he has all of these attributes and Horse Health are following his progress in a series of features, as he reviews practices and attends to fine tuning, which he hopes will help him make the transition.
Going for the Gold, Horse Health, Dec 2007/Jan 2008 Read More
Fatigue
Fatigue is a term that is used frequently but often differently by different people. This paper provides an overview of what fatigue is, the causes of fatigue and specifically addresses indicators of fatigue in the enduance horse.
Dr. David Marlin, The Physiology of Fatigue in Horses During Exercise, 2007 Read More
This power point presentation provides an illustrated overview of fatigue and progression of fatigue to exhaustion in humans. The presentation then focuses on horses and discusses what fatigue is, indicators of fatigue and the progression of fatigue to exhaution.
Dr. David Marlin, The Physiology of Fatigue in Horses, Can Fatigue be Measured, former Head of Animal Health Trust, 2007 Read More
Exercise Induced Pulmonary Hemorrhage (EIPH or “bleeding”)
It is widely believed that 40-70% of all horses experience EIPH (exercise-induced pulmonary hemorrahge), and studies have recently found that some degree of bleeding occurs in 95-100% of exercising horses at some time. At issue is how best to treat EIPH, or prevent it from happening in the first place. Repeated studies have shown that Nasal Strips reduce bleeding. Another practice is the use of the drug called Furosemide (Lasix). One researcher at Michigan State University has suggested the use of furosimide and nasal strips. Additional therapies being investigated include nutrition, venodilators, and hyperbaric oxygen therapy.
Denise Steffanus, Veterinary Spotlight: Racing Blood, Thoroughbred Times, April 18, 2009 Read More
Why do horses bleed internally after exercise? This is a question that has been asked in some form or another for at least the last 300 years. Bleeding in horses was originally spotted when blood ran from a horse’s nostrils after perfoming hard work or running. This condition, called eipistaxis, was consisdered serious, but was never seen as a widespread problem. According to Michigan State University, less than five percent of horses bleed from the nose and mouth after heavy work-the sign many horse owners use as an indication that there is a problem. Most horses that work hard bleed into there lungs without notice to their owners. This article discusses the signs, causes, diagnosis and treatment options for all horses that work hard.
Michael Mahaffey, Guaranteed to Bleed? Barrel Horse News, April 2009. Read More
The first Havemeyer Foundation Workshop on EIPH was held in March of 2006 in Vancouver Canada. 20 participants represented the main horse regions from around the world. While the threshold for haemorrhage and the severity varies between horses it is now recognized that all horses experience some haemorrhage even after light exercise. EIPH is not limited to racehorses, but is a ubiquitous consequence of exercise in all horses in almost all disciplines. EIPH may justify EIPH being considered the most common exercise-related injury that occurrs in horses. This Handbook from the second Workshop builds on the progress of the first Workshop. The Handbook provides new articles, concepts and treatments related to EIPH. EIPH is a complex condition and many factors interact to explain the nature and level of haemorrhage in individual horses under different circumstances. Because of its prevalence, the potential effects on health and perfomance, impact onf the economic value of horses and the fact that manifestation of extreme EIPH is distressing to the lay public, EIPH continues to be a condition that is both challenging and a concern to the global horse industry. Read more
Dorother Russell Havemeyer Foundation Workshop on Exercise-Induced Pulmonary Haemorrhage, San Diego, USA, 30th November-3rd December 2008. The Havemeyer Foundation.
Exercise-induced pulmonary hemorrhage (EIPH) occurs in Quarter Horses, Standardbred and Thoroughbreds worldwide during sprint racing. EIPH is an important cause of exercise intolerance and results from strenuous exercise and/or pathophysiological changes in the equine lung. Read more
H.H. Erickson, D.C. Poole, C.A. Kindig, Current Status of Exercise-Induced Pulmonary Hemorrhage: A New Concept for Prevention. College of Veterinary Medicine, Kansas State University
Research has shown that more than half of all racehorses have some degree of exercise-induced pulmonary hemorrhage (EIPH). Some experts say that number is conservative and that almost every high-performance equine athlete experiences some form of bleeding in the lungs. The key word is degree. For many horses, a small amount of blood leaking into the lungs is absorbed with little to no adverse effect on the individual or its performance. For others, the story is quite different.
Robin Stanback, The Fight For Air: Medication may not be the answer to stop exercised-induced pulmonory hemorrhage. Thoroughbred Times, June 2007 Read More
Exercise-induced pulmonary haemorrhage is a pervasive and important problem of athletic horses, particularly racehorses. Recognising the need for further research into this important problem, the Havermeyer Foundation has sponsored this Workshop as a forum to review current knowledge of EIPH and, perhaps more importantly, to identify areas of future investigation, including definition of specific research problems and approaches to addressing these issues.
Havemeyer Foundation Workshop Exercise-Induced Pulmonary Haemorrhage: State of Current Knowledge 9th – 12th March 2006 Read More
Exercise induced pulmonary haemorrhage (EIPH) is a condition with high prevalence in racing thoroughbreds. However, despite its perceived importance as a cause of morbidity and impared performance, few studies have attempted to address the relationship of EIPH to race performance. This study was conducted to investigate the association between performance and EIPH in a large number of thoroughbred race horses. Endoscopic examinations were performed on 744 horses, representing 52.1% of those eligible horses starting during the study period. The results demonstrate that EIPH has a significant negative relationship with race performance of thoroughbred horses. There is a proportional inverse relationship between severity of EIPH and performance. There is no evidence that EIPH was associated with superior performance. Exercise induced pulmonary haemorrhage is a cause of reduced performance in thoroughbred race horses.
K.W. Hinchcliff, J. McCaffrey, P. O’Callaghan, P. Morley, M. Jackson, J. Brown, A. Dredge, A. F. Clarke, Exercise-Induced Pulmonary Haemorrhage in Thoroughbred Racehorses: Effects on racing performance. A report for the Rural Industries Research and Development Corporation, February 2005
Most body systems of the horse have some capacity to respond to physical training of the type used to improve fitness and performance in Thoroughbred racehorses. The art of training is of course assessing what each horse needs, when to start, when to back off and when to accept that you have reached a suitable level of fitness which should result in a horse being able to get close to achieving a performance consistent with its genetic potential. However, the one body system that training cannot improve on is the respiratory system and this article will highlight some of the implications of this.
The Horse’s Lungs: Training the Untrainable, Dr. David Marlin, Global Equine Group Ltd, Newmarket UK david.marlin@globalequinegroup.com
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