Since the early 17th century, it has
been recognized that many horses that exercise strenuously bleed from their
nostrils during or shortly after a workout, a phenomenon known to horsemen as
"bleeding." For many years, people thought this blood originated from
the nose. However, 20 years ago, a young graduate student from the UC Davis
School of Veterinary Medicine, Dr. John Pascoe, used an endoscope to examine
the airways of horses following racing. He found that the blood originates in
the lungs and he called the disease "exercise induced pulmonary
hemorrhage" or EIPH or Eiphen. Dr. Pascoe found that the majority of
racehorses eventually experience EIPH. More recent studies indicate that
anywhere from 70 to 100 percent of horses in racing and training experience
EIPH. This problem is not only limited to racehorses; horses engaged in any
activity that involves strenuous effort are susceptible, including draft horses
pulling heavy loads.
Bleeding from the lungs during
exercise is rarely reported in any other mammals, yet nearly all horses
experience this bleeding. Why? Research has shown that during exercise, horses
have unusually high blood pressures in the vessels that lead from the heart to
the lungs, two to three times higher than in almost all other species, and
scientists have hypothesized that high blood pressures in the lungs' small
vessels could lead to their breaking, and releasing blood into the airways.
Research has focused on why the blood pressure in the pulmonary blood vessels
is high during exercise in horses, and particularly on whether the high
pressures are required to push the blood through the smaller blood vessels in
the lungs because they are too small and have high resistance.
In an effort to reduce this blood
pressure in the lungs, the diuretic furosemide (Lasix) has been administered to
horses prior to a race. Horsemen use Lasix to make the horse urinate, thereby
slightly reducing the volume of fluid in its circulatory system and hence, the
degree to which the blood vessels are stretched and generate pressure, as in
humans. Although studies have shown that Lasix does lower blood pressure
slightly, it has never been definitively demonstrated that Lasix reduces the
frequency or severity of bleeding. Furthermore, Lasix has numerous undesirable
effects, that is, dehydrating a horse just prior to engaging in heavy exercise,
diluting the urine and making it more difficult to detect illegal drugs, and a
number of other direct and indirect physiological consequences for different
body systems. Evidence also suggests that the sum of these effects is a slight,
but measurable, enhancement of racing performance in horses receiving Lasix.
Ten years ago, Drs. Jim Jones and John
Pascoe of the UC Davis School of Veterinary Medicine evaluated this question
from a different approach. If the high blood pressures in the vessels leading
to the lungs were due to the high pressure needed to push blood through the
lungs themselves, the pressure would be used up as the blood went through the
lungs. Instead, what if the high blood pressure was due to the blood pressure
being high on the output side of the lungs? These blood vessels simply collect
the blood from the lungs and return it to the heart, where it is pumped to the
rest of the body. If the pressure in these vessels were high, then in order for
blood to flow from the lungs to these vessels, the blood pressure in the lung
vessels would have to be even higher. Unfortunately, it is very difficult to
evaluate this hypothesis because the vessels that connect the downstream side
of the lung to the heart are inaccessible. They are deep within the horse's
chest.
Drs. Jones and Pascoe began a series
of studies in which they surgically implanted catheters into the hearts of
horses to directly measure blood pressures. These were very difficult studies
because they required horses to recover from major chest surgery, then return
to maximum performance on the treadmill. The results showed that the pressures in
the heart are unusually high, thus raising the blood pressure throughout the
lung and setting up conditions in which EIPH might occur. In extensive
collaborative studies with the Japan Racing Association, researchers utilized
surgically implanted catheters in conjunction with ultrasound crystals
surgically affixed to the surface of the heart to directly measure the
mechanics of the heart during exercise. These excruciatingly difficult
experiments showed that the fundamental cause of the high pressures in the
heart, and hence the lungs, appears to be the heart's inability to relax
quickly enough between beats during extreme exercise. When the heart is not
relaxed and thus too stiff, it takes higher pressure upstream, in the lungs, to
fill the heart between beats. This finding led to current studies that evaluate
possible methods to enhance the rate at which the heart relaxes during heavy
exercise.
To understand why the horse's heart
relaxes too slowly at maximum exercise, Dr. Jones compared horses with another
mammalian athlete, the pronghorn antelope. Among mammals, pronghorn antelope
have one of the highest abilities to utilize oxygen. They are highly aerobic.
They have a maximum rate of oxygen consumption during exercise that is nearly
twice that of a horse, per unit of body weight. They also are capable of
sprinting at speeds approaching 60 mph and running fully aerobically for an
extended period of time at a speed of 45 mph, that the fastest Quarter Horse
can only reach in a sprint for 20 seconds. However, pronghorn are exceptionally
skittish animals. To study them on a treadmill was a challenge.
Dr. Jones and colleagues spent a month
camped in the sagebrush of northern Colorado to capture newborn pronghorn
fawns. The fawns were then bottle fed and hand-raised for two years until they
were mature and had grown up trained to run on a treadmill. These studies
showed that although the pronghorn is more highly aerobic and its heart pumps
relatively more blood than the horse's, it accomplishes this without the high
blood pressures that occur in the horse. This suggests that body and heart size
may be an important factor in understanding why horses have such high blood
pressures and why their lungs bleed.
Our Conclusions
These brilliant and difficult studies
have gone a long way to establishing that the principal cause of EIPH is high
blood pressure during exertion. If there is excessively high blood pressure,
that puts the heart under considerable extra strain, but that is a consequence
of the pressure, not the cause of it. Studies of the pronghorn make a very
valuable contribution. What has perhaps not been investigated closely is the
unique physiology of the horse, compared with apparently similar animals such
as the pronghorn. During exertion, the normal horse, like the fit human, is
able to output a copious quantity of sweat for cooling, and thus is able to
keep moving all day, so long as there is access to water at intervals. Other
animals have different methods of regulating temperature. The pronghorn runs
with erect body hair, losing heat by radiation and convection, rather than
evaporation like the horse.
The disciplines of training horses for
particular tasks, or performance, necessarily mean that the horse is under
exertion for short periods and at rest for longer periods. This is not a normal
pattern of activity for a horse. The sweat ducts are affected by this adverse
habituation, and some or many of them become blocked as a result. Now when the
horse is under exertion and producing copious sweat, what happens to the sweat
traveling outwards in the blocked ducts? The answer is that the ducts are
ruptured from the pressure of the sweat and the sweat exudes into the
surrounding skin, the lower dermis. This layer of the skin has no sensors so
the sweat is not felt and causes no irritation. In humans this asymptomatic
condition is called miliaria profunda.
The dermis is very richly supplied
with fragile capillary loops. The walls of the capillaries are only one cell
thickness. The exuding sweat ruptures the capillaries, thus cutting thousands
or millions of the connections between the arteries and the veins. The more
intense the exercise, the more sweat is produced, the more capillaries are
lost, and the higher the blood circulation pressure rises. It is this pressure
which causes bleeding in the lungs and distress to the head of the horse.
Fortunately we now have the discovery
of the signaling method of reversing the adverse habituation of the sweat
ducts. By placing a carefully designed "fuzzy logic" signaling device
on the skin of the horse, the sweat ducts unblock and the problem is solved.
Having unblocked the ducts and thus allowing regenesis of the capillaries, the
reversing of the adverse habituation then needs to be reinforced so that it is
long lasting. The signaling device, the Equiwinner Patch, needs to be
replaced and a fresh one put in a different position each twenty four hours for
ten days. By this means the horse does not become accustomed to the signal and
the sweat ducts are returned to their original habituation. This (leaving out
only the detailed microbiology and habituation of sweat ducts) is the full
etiology and treatment of Exercise Induced Pulmonary Hemorrhage and its
associated conditions in the horse.
Cell Signaling
Notes on the basic biology of cell signaling may be found here. As stated in these notes,
"Cells must be ready to respond to essential signals in their environment."
Current knowledge of cell signaling science assumes that the "environment"
is the environment within a multi-cellular organism. However if a single
cell organism is considered, then the "environment" is the surrounding
fluid, commonly either a gas such as air or a liquid such as water, and
any elements in the fluid.
We have therefore concluded that cells of a multi-cellular organism are ready to
respond to elements which are in proximity to, but not within the
organism. Thus the invention of the Equiwinner Patches, which bring elements in close proximity to the horse. We are not
publicly disclosing the precise elements used in the signaling devices on
the Equiwinner Patches, as a matter of commercial confidentiality. We do
not have to disclose them since they have been made inert and do not cross
the epithelial barrier. However, it would be reasonable to assume that the ingredients include naturally occuring minerals. The important thing to know is that no substance enters or is metabolized within the body of the horse.
It will be recognized that the novel use of cell signaling we have described is capable of accurately targeting a reaction in the horse, in a way which is impossible with a drug which has to be put into body circulation. The signaling method also eliminates the possibility of any of the side effects normally found as a result of elimination difficulties and unwanted metabolitites. In addition the "dose" can be calculated and is unvarying.
The above information is offered
for information only and is not meant to be a substitute for the advice
provided by your own veterinarian. You should not rely on the information for
diagnosis of any specific situation. Always consult your own veterinarian for
specific advice concerning the medical condition or treatment of any animal for
whose care you are responsible. Equiwinner Patch is a fully guaranteed product.
Liability is limited to the return monies paid for the product. In no event
will Therapina Ltd be liable for any consequential, incidental, special, or
punitive damages, however caused and under any theory of liability.