“
EQUINE Health
stresses Dr. Emmanuelle Van Erck Westergren of a key
focus at her Equine Sports Medicine Practice in Water-
loo, Belgium.
The prominent veterinarian and thought leader spent
15 years engaged in equine health from a University-
based perspective. She then left academia to apply that
knowledge in private practice, immersing herself in
a 360-degree perspective on horse management. Equine
Sports Medicine Practice specializes in high performance
horses and prioritizes prevention and career longevity.
Dr. Emmanuelle Van Erck Westergren I want to help horses compete successfully over a whole season
52 www.EliteEquestrianMagazine.com
Continued...
Every Breath Horses Take
Affects Every Move They Make.
Kim: How is the equine respiratory system different from a human’s?
Dr. Emmanuelle: Several factors contribute to the horse becoming deficient in
oxygen even in sub-maximal levels of exercise. This state is called hypoxemia.
In man, oxygen levels stay the same during all levels of exertion.
Kim: What are those factors?
Dr. Emmanuelle:
1) Horses breathe only through their nose. There is no communication between
the oral cavity and the airways. Think about exerting yourself while only breathing
through your nose.
2) Their narrow upper airway and the long distance from there into the lungs
makes it that much harder to move the column of air in and out. It’s “dead
space” because nothing happens to the oxygen during the trip. It is only transferred
to the blood stream when it gets into the lungs.
3) Horses breathe in and out at the same rate as their gait. As they canter or
lope, they inhale in suspension, and exhale when their first foreleg hits the
ground. Standardbred trotting horses have an advantage because, if they
become oxygen deficient, they can take a big breath over several trot steps. A
Thoroughbred racehorse is limited because they can’t compensate with a big
breath over a few strides. They have to breathe in and out with their stride. As
they become oxygen deficient, they have to breathe more often, which means
shortening their stride.
4) Horses bodies are over 60% muscle and muscles demand a lot of oxygen.
By comparison, muscle mass for a “normal” 18-40-year-old man is 33% to
39%.
5) Horses have a higher heart rate and that faster circulating blood means it
doesn’t stay anywhere long enough to output all the oxygen it carries.
Kim: Will the horse’s ability to intake and use oxygen improve as his fitness
improves?
Dr. Emmanuelle: Unfortunately, no. The horse’s muscle and heart function
adapt and improve with conditioning, but the oxygen capacity of its respiratory
system does not. Human performance is limited because we have small hearts.
Horses have big hearts that get bigger and can pump more blood with conditioning,
but their performance is still limited because the respiratory system
can’t deliver enough oxygen to the muscles.
“Respiratory
health is
essential to
performance,”
By Kim F Miller
Because of all the limitations, even a little bit of inflammation or obstruction
anywhere in the respiratory tract has a big impact on performance.
Kim: How often to you see sport horses with some type of respiratory disease?
Dr. Emmanuelle: Too often! We have tracked 400 cases in which horses
were referred to our practice for poor performance. Between 50% and 80%
had some degree of respiratory disease. Eventers had 100% and international
show jumpers had 85% at the high end, while driving and leisure horses were
at the “low” end with 50% affected. In a study published last fall, we found that
88% of 731 horses referred for poor performance had Inflammatory Airway Disease,
a range of conditions on the milder end of the Equine Asthma Spectrum.
Kim: Do owners typically recognize poor performance issues as related to
respiratory health?
Dr. Emmanuelle: No. Most of the complaints were very unspecific. “Feeling
heavy” is a top complaint. Heavy breathing, breathlessness, lack of energy
and slow recovery times are more common complaints. Owners seldom noted
coughing or nasal discharge, which are more clear symptoms of respiratory
problems.
Kim: What are some of the biggest risks to respiratory health?
Dr. Emmanuelle: Respiratory diseases fall into the category of Equine Asthma,
a relatively new label in veterinary medicine. Some horses have a genetic
predisposition for it, but otherwise it is an occupational disease. Environment,
stresses of training and competition which can lower immunity, and mingling
with other horses are all risk factors for Equine Asthma.
Kim: How do you figure out what’s causing the problem?
Dr. Emmanuelle: I look at the horse and his environment. We do measurements
of dust levels and samples of contaminants. Some are easy to see.
Have you seen someone sweep dust from the barn aisle, then stash that in the
horse’s stall? Or seen mold stains on barn walls or ceilings?
A condition called Sick Building Syndrome exists in human medicine and it
can apply to horses, too. They may not be coughing or having nasal discharge,
but they clearly don’t feel well. That can often be linked to the amount of contaminants
growing inside the building.
Horses were designed to live outside, but many horses spend 23 hours
a day in the barn. Living inside, they’re exposed to 50 times more inhalable
irritants! Even if they live outside, if they’re getting hay with contaminants, it’s
still a problem.
and a whole career,” Dr. Emmanuelle explains. Accomplish-
ing that involves working with owners to evaluate and implement
best management practices related to every aspect of their horse’s
health. Respiratory function is critical to that, yet often under-appreciated
and misunderstood. Worse, warning signs of trouble are easily missed or
misinterpreted.
That’s why Dr. Emmanuelle welcomes the chance to speak on equine
respiratory health, as she did here with journalist Kim F Miller.
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